___________________

¹ DEIA stands for diversity, equity, inclusion, and accessibility, a phrase used to define policies, behaviors, and beliefs that support the opportunity for all to participate and develop within a community. The “+” includes anti-racism, accountability, and justice.

the ambitious science and space weather guiding questions and realistic by prioritizing research focus areas that are compelling and where significant progress will be made in the next decade.

This research strategy, summarized in Figure 5-2, is comprehensive in that it addresses all of the themes in Chapters 2, 3, and 4 and all of the funding agencies: the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), the National Science Foundation (NSF), and the Air Force Office of Scientific Research. In addition, this strategy has important international and cross-divisional contributions. In fact, the strategy is realized only through combined investments of these agencies in ground- and space-based observations, theory and modeling efforts, research and analysis, and development of the workforce to meet the broader needs of the field.

The strategy is balanced in that it includes research for the entire community to participate in shaping solar and space physics in the next decade. One common theme in both science and space weather research (Chapters 2 and 3) is that the local cosmos must be studied as a system, which requires the data from an integrated HelioSystems Laboratory (HSL) and the analysis and workforce development in DRIVE+.² While this theme is in common with both science and space weather, the other four themes in science and space weather carry equal weight in this balanced strategy. This balance is necessary to make significant progress on all science focus areas and achieve all space weather outcomes.

There are several critical elements to the strategy that are organized into three broad categories (Figure 5-2). The HSL and DRIVE+ are defined in Sections 5.2 and 5.3, respectively. DRIVE+ includes technology development that is needed for the assets in the next decade. Section 5.4 presents the preparation for beyond the next decade, including the technological and programmatic preparation that needs to occur in the next decade to prepare solar and space physics for beyond the end of the next decade. Chapter 6 includes the budget implications and decision rules for the research strategy and summarizes Chapter 5, including a summary of all recommendations in the report.

Figure 5-3 provides a timeline representation of the decadal research strategy, illustrating how the critical elements of the strategy are woven together to make significant science and space weather progress over the next decade. The figure also shows how existing programs are interleaved with new missions and programs. One new program is the flagship community science modeling program discussed in detail below. A major component of

___________________

² The 2013 decadal survey introduced the original Diversify, Realize, Integrate, Venture, Educate (DRIVE) initiative, a long-term framework for organizing and enhancing agency research programs that reflects the need for interagency cooperation. The recommended research strategy transforms DRIVE into DRIVE+ an includes recommended enhancements in supporting research and technology programs that are essential for realizing ambitious scientific progress.

this strategy includes two discovery-enabling new NASA missions (see Figure 5-3). The new Solar Terrestrial Probes (STP) mission is represented by the notional Links mission, a groundbreaking combination of an in situ constellation and remote sensing imaging spacecraft of the highly structured magnetospheric and ionospheric plasmas in a heterogeneous constellation. This mission applies innovative technology to provide definitive answers to long-standing questions on global solar wind energy entry on the day side of the magnetosphere, and subsequent energy transport through the night side of the magnetosphere to the aurora and regions of large-scale currents. Furthermore, this mission determines the impacts that “intermediate-scale” or meso-scale processes have on the larger-scale evolution of the system. The answers and fundamental understandings from this mission are of high relevance for accurate and timely space weather predictions. The combined Geospace Dynamics Constellation (GDC) and Dynamical Neutral Atmosphere–Ionosphere Coupling (DYNAMIC) missions (the high-priority missions from the 2013 solar and space physics decadal survey report [NRC 2013; hereafter “the 2013 decadal survey”] that are currently under development) act as a forerunner for technologies related to operating a heterogeneous constellation like the Links mission, where different spacecraft perform different observations.

The second discovery-enabling new NASA mission is a solar polar mission, represented by the notional Solar Polar Orbiter in the Living With a Star (LWS) program. This exploratory mission will, for the first time, measure magnetic fields and velocity structure for extended periods at the Sun’s poles. These measurements are critical for understanding the origin of the solar magnetic dynamo and how the magnetic field drives solar activity and

shapes the heliosphere over the course of the solar cycle. Understanding the polar fields and velocity structures is also a key factor in predicting space weather approaching Earth. Its vantage point enables comprehensive study of the creation and structuring of the solar corona and solar wind.

The research strategy timeline in Figure 5-3 also includes critical new ground elements—a new NSF Major Research Equipment and Facilities Construction (MREFC) project and two new NSF Mid-scale Research Infrastructure (MSRI) projects. The next-generation Global Oscillations Network Group (ngGONG) is the MREFC project in Figure 5-3 that is an enhanced successor to the National Solar Observatory’s (NSO’s) Global Oscillations Network Group (GONG) network. This comprehensive ground-based network is the first to include operational space weather requirements from its conception. The highest-priority, ground-based, mid-scale projects in Figure 5-3 are a MSRI-1 observing system simulation experiment (OSSE) study of Distributed Arrays of Small Heterogeneous Instruments (DASHI) and an MSRI-2 implementation of the Frequency-Agile Solar Radiotelescope (FASR). Both critical mid-scale projects perform important ionosphere–thermosphere–mesosphere (ITM), magnetospheric, and solar heliospheric science and broadly serve the ground-based solar and space physics community.

The missions and projects described above are key components of the integrated HSL. The full HSL takes advantage of these new missions and projects, HSL components already in operation, HSL components in development, and an enhanced model and simulation program within the HSL to achieve the ambitious and exciting science and space weather research described in Chapters 2 and 3. In this sense, the HSL is the ultimate resource, or laboratory, that the solar and space physics community uses to understand the complex and intertwined systems that make up the local cosmos. The HSL includes, but is distinct from, the NASA Heliophysics System Observatory (HSO) and relies on the integration within and across agencies and foundations to achieve this science and space weather research.

Significant progress on the entirety of the research guiding questions will not be possible without additions to this HSL, beyond the LWS and STP missions and the MREFC and MSRI projects described above. In particular, there is a growing need—driven in part by rapid advancements of spacecraft and instrument technologies—for a new NASA Explorer class that falls between the current Medium-Class Explorers (MIDEX) and larger-scale LWS and STP lines. To fill this mission cost gap and contribute to the balance of the overall research strategy, the decadal survey committee recommends establishing the Heliospheric Large Explorer (HeLEX) (see Section 5.2). HeLEXs are comparable to principal investigator (PI)-led New Frontiers missions in the NASA Planetary Science Division and expand the opportunities for PI-led scientific missions. The HeLEX class of missions would enable the realization of, for example, smaller-scale constellation missions, which have become increasingly important for studying the heliophysics system of systems.

There are a number of high-priority NASA missions whose development continues in the next decade and these missions are key elements of the research strategy. They include Explorer missions, the Interstellar Mapping and Acceleration Probe (IMAP), GDC, and DYNAMIC. As this decadal survey builds on the 2013 decadal survey that prioritized these missions, they contribute significantly to science progress and provide important balance to the overall research strategy in the next decade.

Space weather research in the next decade benefits from cross-agency coordination and collaboration as prescribed by the 2020 Promoting Research and Observations of Space Weather to Improve the Forecasting of Tomorrow Act (PROSWIFT Act; P.L. 116-181). This act outlines the space weather roles and responsibilities of the various agencies and the quad-agency memorandum of agreement, signed in 2023, among NASA, NSF, NOAA, and the Department of the Air Force, outlining opportunities for collaboration. The coordination groups around space weather (see Chapter 3 for details) are paving the way for efficient use of resources with increased scientific and societal impacts. For solar and space physics, such coordination and collaboration are major steps forward, and the space weather recommendations highlight some further steps that would continue the positive development.

Basic science research and technology development programs are the backbone of the research strategy. The 2013 decadal survey (NRC 2013) took an important step toward organizing research and technology programs with its recommendation of the DRIVE initiative. DRIVE continues to be a powerful organizational tool for research and technology programs into the next decade. It is multiagency, building on the strengths and investments of each agency, while reflecting the interagency cooperation needed to achieve decadal survey science goals. This decadal survey’s research strategy for the next decade includes a transformation of DRIVE into DRIVE+ (Section 5.3). In Figure 5-3, DRIVE+ is part of the research strategy timeline. Where the integrated HSL provides all the data for

the science in the next decade, the science is accomplished through the vibrant research program that is DRIVE+. DRIVE+, like the integrated HSL, has existing elements as well as new enhancements in the research program for the next decade.

The research strategy extends beyond 2033, the end of the decadal survey interval. An important element of this strategy is the preparation for future decades (Section 5.4). This preparation includes developing new technologies and important interagency and international developments to pave the way for implementation of the inherently collaborative and international solar and space physics strategy beyond the next decade.

The investments that are needed to support the research strategy are described in Chapter 6.

5.2 AN INTEGRATED HELIOSYSTEMS LABORATORY

5.2.1 Introduction to the HelioSystems Laboratory³

The decadal science and space weather themes (Chapters 2 and 3) encompass scientific research that requires diverse sets of heterogeneous observations. However, the vastness of the local cosmos will always leave much of the space unobserved; thus system-level models are required to fill the gaps, provide the large-scale context, and bridge spatial and temporal scales. This section introduces the concept of an integrated HSL to describe all the missions, projects, and program elements that generate the data sets (from both observations and models) that are key to expanding the frontiers of solar and space physics and enabling significant progress across the broadest range of science and space weather themes.

There is already significant progress on these themes. For system science, NASA has moved toward managing its Heliophysics Division fleet as a coherent network, the HSO. The 2019 report Progress Toward Implementation of the 2013 Decadal Survey for Solar and Space Physics: A Midterm Assessment (NASEM 2020a) recommended that NSF and NASA coordinate their respective ground-based and space-based assets. The PROSWIFT Act codifies the space weather roles and interagency cooperation for NASA, NOAA, NSF, DoD, and the Department of the Interior (DOI). Notably, most of the NASA mission concepts submitted to this decadal survey (through community input papers) were constellation and/or remote sensing missions and, in many cases, these missions consisted of heterogeneous elements combining a variety of measurements from best-suited vantage points, including from the ground. Many of the concept ground-based facilities also consisted of distributed arrays of heterogeneous instrumentation or imaging arrays. There is a fundamental paradigm shift from individual spacecraft or ground-based facilities to heterogeneous constellations and integrated arrays of ground-based facilities that is emerging in solar and space physics for the next decade. Multiagency coordination between ground-based and space-based assets is needed to effectively achieve system science objectives.⁴

Solar and space physics is inherently transdisciplinary and requires a systems approach to understand the complex interactions between domains over a wide range of spatial and temporal scales. This necessitates comprehensive measurements around the globe, and from multiple vantage points in the space environment. Solar and space physics is therefore a global enterprise for which international collaboration is not just desirable, but necessary.

In the next decade, U.S. leadership in the international solar and space physics community requires development of diverse platforms of in situ and remote sensing instrumentation. This instrumentation must provide spatially distributed measurements with temporal continuity and integrated data processing. These measurements need to be supported by large-scale, system-level modeling to fully understand the diverse phenomena throughout our local cosmos. Integration of all solar and space physics ground-based and space-based assets is accomplished through NASA, NOAA, NSF, and Department of the Air Force–Air Force Office of Scientific Research (AFOSR) strategic science partnerships, complementing the space weather partnerships that have formed for coordination and collaboration on space weather research-to-operations-to-research programs. The vision for solar and space

___________________

³ This section was modified after release of the report to correct agency responsibilities for ground-based infrastructure.

⁴ This paragraph was modified after the release of the report to provide factual clarity regarding multiagency coordination for achieving the next decade’s science goals.

physics for the next decade to discover the secrets of the local cosmos and to expand and safeguard humanity’s home in space is realized with an integrated HSL, discussed below.

The collection of individual elements in the HSL described in this chapter is a “laboratory” in the broadest sense of the term, defined as a source of scientific and operational data. The laboratory is not confined to a specific type of element (e.g., a space-based mission or missions that would constitute an observatory). Rather, the HSL encompasses a wide range of elements that may be space-based, ground-based, or, analogous to the equipment (measuring devices, computers, etc.) used in a laboratory, theory and modeling. These assets are used both to conduct scientific experiments and to make space weather forecasts and predictions.

In this laboratory, the solar and space physics community conducts investigations into and makes predictions about heliosystems. This term is a shorthand for all the systems in the local cosmos, including the Sun, the heliosphere, and planetary magnetospheres, ionospheres, thermospheres, and mesospheres (including Earth’s). The interplay within and among all these heliosystems and the comparison of these systems to other stellar systems is the essence of solar and space physics.

A key attribute of this laboratory is that it is integrated. A common scientific and space weather theme that prevails in this report (see Chapters 2 and 3) is the interconnectedness of all regions and entities under study. The next decade heralds a new era where the primary way to make progress on this common theme is to employ the assets of an integrated HSL.

Another key aspect of this integrated HSL is that major advances on critical science and space weather questions will require missions or combinations of missions that provide large-scale, heterogeneous constellation measurements, measurements from both the ground and space, and measurements within and away from the Sun–Earth line. In the next decade, single- and multiple-spacecraft missions will continue to provide critical observations to answer targeted questions—for example, in science theme 2, A Laboratory in Space; Building Blocks of Understanding. At the same time, these missions will add to the heterogeneous measurements of the HSL. Thus, missions will have a dual nature where they address fundamental science and at the same time add to the system. Also in the next decade, the Sun–Earth line will continue to be an important vantage point to explore and diagnose the Sun–Earth system. However, other vantage points have grown in importance as necessary for a full understanding of the dynamics of the Sun and the space between it and Earth.

An underexploited dimension to international science collaborations is to leverage extant ground- and space-based instruments to jointly attack problems of interest. Such efforts require close cooperation and coordination. Examples include the Whole Sun Month (Biesecker et al. 1999), the Whole Heliosphere Interval (Woods et al. 2009), and the Whole Heliosphere and Planetary Interactions international campaigns (Gibson et al. 2023; UCAR 2024). These efforts have been largely voluntary with limited resources available at the institutional or agency level. The development of tools to enable coordinated observations, coordinated data analysis, and data sharing between international partners would facilitate such collaborations.

Increasing the lead time and accuracy of space weather predictions requires monitoring the Sun and solar wind with ecliptic and off-ecliptic vantage points, each having their own benefits. Collaboration with the European Space Agency (ESA) on the Vigil mission provides an opportunity to demonstrate the capabilities of solar and solar wind monitoring from what will be a novel vantage point in the ecliptic, but away from the Sun–Earth line. (See also Section 5.2.3.) Vigil’s operational demonstration supports the NASA Artemis Moon to Mars initiative, which requires monitoring the inner heliosphere over a wide range of solar longitudes as the relative positions of Earth and Mars vary over time. The collaboration with ESA also underscores the important role that international collaboration plays in the integrated HSL.

Conclusion: Achieving the vision for solar and space physics and realizing the research strategy requires significantly enhanced communication within and across the funding agencies. Meeting the diverse observational (both ground-based and space-based) and modeling needs is achieved only through an interagency strategic planning activity. Such planning would allow evaluation of missions and projects based solely on traceable implementation plans and ensure that the needs of all agencies are addressed, from fundamental science to space weather research and applications. Lastly, an interagency strategy would foster coordinated use of resources across agencies without explicit community direction in each case.

___________________

⁵ This language was changed following the release of the report to clarify the roles of the agencies to which this recommendation is directed.

___________________

⁶ This section was modified after release of the report to correct agency responsibilities for ground-based infrastructure.

⁷ Although AMPERE measurements are from a space-based data buy, it is included here because NSF has supported its coordination and implementation for many years.

three-dimensional (3D) at radio wavelengths (frequencies from 200 MHz to 20 GHz) from the midchromosphere up into the midcorona with a high degree of angular (1″ at 20 GHz) and temporal resolution (as high as 20 ms). This innovative array (Figure 5-5) measures the plasma state of the solar atmosphere in less than 1 second (snapshot imaging) with a high degree of fidelity and dynamic range.

The unique characteristic of FASR is its ability to make quantitative measurements of chromospheric and coronal magnetic fields, both on the disk and above the limb, in both quiescent plasma and in energetic and dynamic phenomena such as flares and coronal mass ejections (CMEs) and to measure the spatiotemporal evolution of the electron distribution function for both quiescent and explosive phenomena. As a 3D “camera,” FASR will observe the Sun’s atmosphere as a coupled system, providing entirely new perspectives on its role as the central driver of heliosystems.

areas. The instruments may include scanning Doppler imagers, Fabry-Pérot interferometers, all-sky imagers, global navigation satellite system (GNSS) receivers, meteor radars, magnetometers, ionosondes, and other instrumentation. DASHI complements the incoherent and coherent scatter radars (the existing and planned various incoherent scatter radars and the SuperDARN network). Because most of the instruments have been successfully deployed before, the concept is technologically mature.

The DASHI concept could be realized in multiple ways in terms of number and location of observing sites as well as the instrumentation. Several implementation options were described by the decadal survey panels. It is clear that a comprehensive network, such as that illustrated in Figure 5-6, is well beyond the Distributed Array of Small Instruments (DASI) in number and complexity of the instrumentation. However, OSSE modeling studies are needed to determine the optimal number and location of the DASHI sites in terms of balance between observing requirements that are tied to science objectives and available resources, including the cyber-infrastructure needed to support scientific use and interactions between the DASHI sites. The completed OSSE, followed by deployment of prototype instrument arrays, will yield a cost estimate that determines whether a full-scale DASHI is realized

through the NSF MSRI-2 or the MREFC line. The OSSE and associated planning and prototyping activities are a good match to the MSRI-1 track.

Conclusion: DASHI combines new and existing resources to create a distributed array for the NSF geospace community to enable a transformative systems science approach to mesosphere–thermosphere–ionosphere–magnetosphere coupling. Before full implementation, the DASHI concept requires OSSE modeling studies to determine the optimal number and location of DASHI sites and their optimal instrumentation to maximize the ITM and magnetospheric science return, as well as associated planning and prototyping activities to determine the cost.

The combined FASR and DASHI high-priority projects benefit both the solar and geospace communities. In fact, the combined projects constitute a strategic plan for convergent research that crosses the NSF Mathematical and Physical Sciences (MPS) and Geosciences (GEO) directorates. Furthermore, these two projects contribute to space weather research. As such, this plan for the MPS and GEO communities is synergistic with recommendations to better coordinate solar, geospace, and space weather research at NSF.

The ground-based projects in Recommendations 5-2 and 5-3 are those that best contribute to the comprehensive, balanced research strategy. Other high-priority projects considered for the various NSF programs are listed in Table 5-2 in alphabetical, but not in priority, order.

While there is keen interest in mid-scale infrastructure, larger investments in ground-based infrastructure in support of solar and space physics are also needed. The ngGONG (Figure 5-7) is a modern and enhanced successor to the NSO’s GONG network. Originally deployed in 1995, GONG was designed to explore the Sun’s interior using helioseismology with homogeneous instrumentation on six sites distributed around the globe to provide continuous observations of the Sun. The network was later enhanced to make Hα observations. GONG has also become a valuable space-weather asset, as the project has made magnetograms and far-side images available.

Now approaching 30 years of service, GONG is an aging infrastructure that is difficult to maintain and operate. Yet, its measurements have become more important than ever before, both for scientific research and space weather operations. These important measurements will be extended by ngGONG. For scientific research, ngGONG will continue and expand critical measurements on the Sun–Earth line complementing the space-based observations, enabling more comprehensive study of the Sun’s interior, the nature of the solar magnetic dynamo, and mapping solar activity on the far-side of the Sun. For space weather operations, ngGONG will continue to be a critical part of the infrastructure for space weather operations.

The ngGONG facility will be the first ground-based network that includes operational space weather requirements from its conception. Cost estimates suggest that ngGONG is appropriate for development and deployment under the NSF MREFC line. However, as a facility that plays a role in both research and space weather operations, and because it is inherently international in nature, ngGONG requires collaboration with NOAA, DAF-AFOSR, and international partners such as the European counterpart to ngGONG, the Solar Physics Research Integrated Network Group (SPRING) of the SOLARNET project.

Conclusion: With its combined science and space weather operations mission, ngGONG is an example of a facility with dual purpose in the integrated HSL.

Recommendation 5-3: The highest-priority large Major Research Equipment and Facilities Construction-scale project for the National Science Foundation for the next decade is the Next Generation Global Oscillations Network Group (ngGONG). In light of its importance to space weather, the development, implementation, and operation of ngGONG should be supported through partnerships with the National Oceanic and Atmospheric Administration, the Department of Defense-Air Force Office of Scientific Research, and international partners.

Table 5-3 summarizes mid-scale and large investments projects considered by the three science panels and prioritized by the steering committee.

In the next decade, the NSF contributions to space weather will increase significantly. Several of the existing and future NSF facilities support and provide key data for space weather observations (see Table 5-4). To integrate these increased contributions into NSF and into the national space weather endeavor, NSF needs an agencywide plan. The recommendation that NSF develop this agencywide strategic space weather plan is in Chapter 3 (see Recommendation 3-1).

Ground-Based Infrastructure for Space Weather

Ground-based infrastructure provides valuable information for space weather with importance to both predictions and monitoring of the current state of the system. Similar to their space-based counterparts, ground-based

space weather assets range from dedicated operational monitoring systems, controlled by a variety of organizations to science instrumentation, which also serves as a source of space weather information. An example of such dual use is the solar monitoring provided by ngGONG (see the discussion above and Table 5-4). In the next decade, the synergy between NOAA and other agencies will be expanded and enhanced. For both ground- and space-based data, the use of NOAA data in scientific research and the use of scientific data in NOAA research will be key to advancing the research strategy. For NOAA, Recommendation 3-7 (see Chapter 3, Section 3.3.5) states that the agency should take advantage of new data opportunities by assessing the value of new data streams. This recommendation includes both ground-based and space-based data streams.

Ground-based space weather assets are not limited to the NSF assets in Table 5-4. The U.S. Air Force 557th Weather Wing has the responsibility for providing space weather information to all DoD services worldwide, which it does by operating the Space Weather Operation Center and by providing data to NOAA Space Weather Prediction Center (SWPC). Data from the Solar Electro-Optical Network (SEON) and Radio Solar Telescope Network (RSTN) are publicly available but not all other data are accessible. To maximize the potential of these space weather assets, they need to be integrated and managed strategically, and made publicly accessible. The PROSWIFT Act provides some guidance by identifying which agencies are responsible for which assets.

TABLE 5-3 Summary of the Highest-Priority Ground-Based Projects for the National Science Foundation Programs

NOTE: MSRI, Mid-scale Research Infrastructure; OSSE, observing system simulation experiment.

___________________

⁸ For reference, a large part of the NCAR annual budget of $100 million goes toward supporting community Earth system modeling (Slingo et al. 2022). The UK meteorological office is procuring more than $1 billion over the next decade for the hardware required to support climate modeling (e.g., https://www.hpcwire.com/2021/05/13/behind-the-met-offices-procurement-of-a-billion-dollar-microsoft-system).

Numerical simulations of such systems require developing highly complex models that encapsulate different physical regimes, couple disparate spatial regions, and cover an enormous range of length scales. The challenge is analogous to simulations of fusion devices, nuclear reactors, or numerical prediction of weather and climate. A good example of a complex community model with sustained infrastructure is the Community Earth System Model (CESM). This model was developed for climate prediction by the National Center for Atmospheric Research (NCAR) in collaboration with the larger research community.

State-of-the art solar and space physics models already push the boundaries of physical and algorithmical complexity. However, modeling efforts by individual groups are hampered by a lack of sustained infrastructure necessary to harness already available and emerging software and hardware technologies. Computational capacity has increased by roughly three orders of magnitude in the past decade. The world’s first exascale supercomputer entered production in 2022. Cloud resources now play a growing role in all aspects of HPC, data analysis, and storage. AI, machine learning, and data mining are increasingly used for improvement of numerical algorithms, model-data fusion, and analysis of big data produced by the models. These transformative advances in supercomputing present a unique and timely opportunity to tackle open questions involving cross-scale and cross-domain coupling (see Chapter 2), setting solar and space physics on the precipice of new discoveries. Moreover, it allows the United States to maintain leadership in space environment modeling, which has both scientific and national security implications.

To bring about this new era of discovery, the solar and space physics community needs a framework that allows models to efficiently utilize the largest supercomputers and other HPC systems and take advantage of cloud and AI resources, while enabling broad community participation in algorithmic and model development and use. Challenges in harnessing modern HPC technologies include porting highly complex models, often consisting of multiple interconnected components, to increasingly heterogeneous supercomputer architectures while in a way that achieves performance that allows capable simulations on a massive scale.

Development and maintenance of software for such models requires sustained curation of large and complex code bases and improving model fidelity, which demands a new level of error analysis, uncertainty quantification, and data assimilation. The implementation of sustained maintenance of large ensembles of curated uniform data streams, standardized file formats, and testbeds entails large intellectual, computational, communication, storage, and system administration resources. Open accessibility implies development and maintenance of software that will enable broad research community participation including contributions to open source code development, performing model runs, and carrying out analyses based on simulation data. All the above requires sustained infrastructure for training, hiring, and retaining a new type of interdisciplinary workforce with overlapping expertise ranging from HPC-specialized research software engineers to experienced applied mathematicians, domain scientists, and program managers. Such a sustained, professional workforce is paramount to meeting the nascent modeling challenges in solar and space physics but is not being achieved within the current hierarchy of the funding programs.

The solar and space physics community is ready to embrace the open science and open software paradigms. However, even the largest modeling programs currently cannot efficiently serve the broader community, because the programs do not have the resources to recruit the necessary workforce, nor do they possess the sustained infrastructure to retain it. Therefore, a new paradigm is necessary to implement an open science approach to solar and space physics modeling. This new paradigm should incentivize and develop the new modeling workforce in ways that allow appropriate prioritization of both scientific throughput and development of community models. The flagship-level community modeling program recommended below would be a prime example of NASA’s commitment to open science.

Conclusion: A significant expansion of the funding hierarchy for theory and modeling is needed to meet the challenges of ever-increasing physical complexity of the models, rapid development of the high-performance computing landscape, and adherence to open science standards.

Recommendation 5-4: In addition to maintaining the current range of grant opportunities for theory and modeling, the National Aeronautics and Space Administration (NASA) should establish a flagship-level heliophysics community science modeling program capable of addressing heliophysics problems that have broad community interest and that require complex community models. This program should be funded at a level that enables training, hiring, and retaining interdisciplinary teams of highly specialized professionals. NASA should establish a sustained

infrastructure for these core teams to engage community participation in developing, using, and maintaining the models. To define and implement the program, NASA Heliophysics Division should gather community input and consider examples (e.g., the various Earth system models) from other NASA divisions, other federal agencies, and international organizations.

A critical part of space weather operations is the use of models, data assimilation, and AI methods. The use of these methods assembles available observations into a coherent framework that describes the past sequence of events and predicts future evolution. The NASA flagship community science modeling program described above focuses on the three science themes of Chapter 2 and not on real-time monitoring and predictions. Thus, the operational space weather organizations should join forces to support a parallel modeling effort where the increased scientific understanding from the flagship community model is transitioned to operational services, as described in Chapter 3, Recommendation 3-4.

5.2.3 Space-Based Assets in the Integrated HSL

The science and space weather guiding questions and focus areas introduced in Chapters 2 and 3 require an integrated HSL that has a wide array of space-based measurements. Measurements of the heliosystems include remote sensing and in situ techniques. Most often, remote sensing requires space-based observation platforms because of the need to have different vantage points, duration and cadence of the measurements, and measurements above the dense atmosphere of Earth. In addition, almost every science focus area in Chapter 2 requires in situ measurements of plasmas (including thermal plasma through energetic particles), neutrals, and magnetic and electric fields in regions from very close to the Sun and Earth to out into the local interstellar medium.

Figure 5-8 shows that the NASA space-based and selected NSF-funded elements of the integrated HSL include NASA and NSF CubeSats, sounding rockets, balloons, the existing HSO, the Explorers and Missions of Opportunity (MOs), space weather missions, and the STP and LWS Heliophysics mission lines. Cross-divisional collaboration within NASA brings in measurements of the interplanetary medium by planetary missions in their cruise phase between Earth and their planetary targets, as well as potential data from the outer heliosphere boundaries from the Planetary Science Division’s New Horizons mission. Figure 5-8 also shows selected NSF facilities, including the recently commissioned Inouye Solar Telescope and the new ground-based facilities recommended by this decadal survey. In the next decade, combining ground-based and space-based assets is important for the comprehensive research strategy.

Acquiring these measurements requires data links from the space-based assets to the ground. These links become increasingly challenging as the number of space-based assets increases and the assets move farther from Earth into interplanetary and even interstellar space. In addition, new, increasingly sophisticated instruments produce large quantities of data while science investigations require measurements at high cadence and space weather operations require these measurements in (near) real time. Thus, continuous transfer of large data quantities over long distances becomes a significant bottleneck to achieving both the science and space weather goals. Elimination of these bottlenecks requires upgrades and expansion of data receiving and processing ground facilities; specific recommendations for these communications facilities are provided in Section 5.4.

NASA Suborbital Program

From its inception, NASA’s suborbital Sounding Rocket and Scientific Balloons Programs have had a two-pronged focus on both technology development and science. These smaller- and shorter-timescale projects have provided significant achievements both independently focusing on targeted research questions and as complementary elements in support of larger missions. In addition, the program has advanced instrument concepts for future explorer and strategic missions and expertise in the solar and space physics community. For example, the Twin Rocket Investigation of Cusp Electrodynamics (TRICE-2) sounding rockets produced significant science results on the physics in Earth’s magnetospheric cusps, while providing a significant technology development step for the Tandem Reconnection And Cusp Electrodynamics Reconnaissance Satellites (TRACERS) Small Explorer (SMEX) mission. Another highly prolific suborbital mission has been the Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) mission that flew multiple campaigns during the Van Allen Probes era (and beyond). BARREL

provided unique scientific insight as well as providing context for and comparison to Van Allen Probes radiation belt observations.

The sounding rocket program provides primary access to the “ignorosphere” at 80–300 km in altitude, where satellite orbits rapidly decay, and balloons cannot reach. However, the fundamental plasma physics that can be studied in this hard-to-reach region is not to be underestimated: neutral winds and upper atmosphere composition, auroral emissions and related current structures, energy dissipation through Joule heating and wave-particle interactions all are fundamental aspects of the ITM system and its coupling to the magnetosphere above and atmosphere below.

The high-altitude balloon program has been instrumental in accessing the upper atmosphere and viewing space from a stable platform that can stay aloft for days to weeks (in contrast to sounding rockets whose flights last on the order of 10 minutes). Balloon programs have contributed valuable science to studies of the Sun, the auroras, and other emissions from particle precipitation and its impacts on the upper atmosphere.

While suborbital flights are often used as testbeds for new instrument and concept developments, they also provide training of students and early career researchers in the rigors of spaceflight missions, preparing them for future hardware responsibilities and leadership positions. Rocket and balloon missions are ideal training grounds for future PIs of Explorer missions, instrument suites, and other mission involvement. The skillsets developed include exposure to the NASA mission architecture, team management, complex budget and schedule preparation, and a multitude of leadership credentials. The support and expansion of these programs is vital to producing a future set of instrument-providers and leaders for NASA PI-led missions (see also Section 5.3).

NASA and NSF CubeSats

The proliferation and capabilities of CubeSats have grown significantly over the past decade since NSF took the lead by implementing a modest but highly successful CubeSat program in 2008. One of NSF’s first missions, CSSWE (Colorado Student Space Weather Experiment) was launched in 2012 and contributed to at least 24 peer-reviewed publications, including in the journal Nature (Baker et al. 2014; Li et al. 2017). In a review of early CubeSat missions, Spence et al. (2022) quantitatively demonstrated that they had weighted publication impact factors comparable to those of larger missions. CubeSats (e.g., CSSWE and Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics [FIREBIRD]) have also been used in support of major missions such as NASA’s Van Allen Probes.

NASA provided technical support for NSF’s program early on, and the agencies have jointly supported projects. The highly successful Electron Losses and Fields Investigation (ELFIN) mission made groundbreaking discoveries about radiation belt electron precipitation and plasma wave-particle interactions. To date, more than 35 peer-reviewed publications in high-impact journals are based on ELFIN observations. Since the 2015 launch of the first NASA Heliophysics Division science CubeSat, the Miniature X-ray Solar Spectrometer (MinXSS),⁹ NASA’s CubeSat program has expanded significantly. As of early 2024, 13 CubeSat missions had launched, and 14 were in development.¹⁰

Although typically funded through the research and analysis (R&A) program, suborbital and CubeSat projects are included in the HSL because of their scientific and data contributions. With the intention to offer low-cost access to space, the CubeSat program provides important program balance at NASA. However, a program that was envisioned originally as inexpensive (~$1 million per mission) has grown in complexity and cost (current mission costs range between $4 million and $8 million) and has been hampered by internal and external problems; even with the explosion of launches by the commercial sector, launch opportunities for CubeSats suffer from lengthy delays and cost growth. New launch companies available through the Venture Class Launch Service (VCLS) demonstrations have been plagued by delays and launch failures. The COVID-19 pandemic had a significant impact both on teams and on the supply chain. Although these issues are mostly resolved, CubeSat projects, which may have all the complexities of a larger mission, have no reserves and therefore less resiliency to deal with problems.

___________________

⁹ MinXSS made new observations of the solar X-ray spectrum, was the first CubeSat mission to demonstrate pointing control better than 10 arcsec and led to more than 30 publications. It was followed by MinXSS-2, which was launched in 2018.

¹⁰ This number does not include CubeSats that are part of larger missions—for example, Explorers—which are becoming more common. See NASA (2024c).

As the costs have increased, the engagement of smaller institutions and early career PIs has become increasingly challenging, because they may not have sufficient resources in the proposal phase to compete against institutions that have large internal teams and funding. Furthermore, there is growing concern over the right level of management oversight, which contributes to the increased total program costs.

The community has also voiced a need for better support for project teams in addressing issues such as radio licensing and ground station access, as well as better opportunities for community input to NASA and sharing of lessons learned. Maximizing the return on investment in the CubeSat program calls for assessment of project costs, program structure, as well as identification of potential solutions to the challenges described above. After nearly a decade over which the program has grown, a review to ensure its continued success would be beneficial.

The NSF CubeSat program, despite its early successes, appears to have stagnated. The midterm assessment of the 2013 decadal survey pointed out that the CubeSat solicitation was not offered in 2016 or 2017 when the program was reinvented as the Foundation-wide CubeSat Ideas Lab program. In 2022, five NSF-supported CubeSat missions were expected to launch in 2023–2024 timeframe (Sharma 2022). However, the agency has not solicited new proposals since 2019. The Physics Division has established a new cross-NSF program in partnership with the GEO and ENG directorates—Ecosystem for Leading Innovation in Plasma Science and Engineering (ECLIPSE), which supports sensor development for CubeSats (NSF n.d.). The 2017 National Academies of Sciences, Engineering, and Medicine’s report Assessment of the National Science Foundation’s 2015 Geospace Portfolio Review recommended that “the NSF Geospace Section carefully consider the impact associated with decreasing funding for the CubeSat program before additional resources through intra-divisional partnerships can be obtained” (NASEM 2017, p. 35).

Conclusion: The CubeSat programs at NASA and NSF are important elements of the HSL, contributing data and scientific results. These programs continue to be valuable and need to continue meeting the original goals of science, training, and participation.

Recommendation 5-5: To ensure continued success, the National Aeronautics and Space Administration and the National Science Foundation should conduct comprehensive, community-based reviews of their CubeSat programs.

Recommendation 5-5 is written generally so that NASA and NSF determine their own means to go about the review of CubeSat programs. However, important aspects to consider include, but are not limited to, the following:

• Balance between technology demonstration, education, and science investigations and the appropriate risk postures for each;
• Methods for sharing lessons learned and enhancing support for potential or inexperienced PIs. One possibility would be to expand activities where experienced NASA scientists and engineers work directly with the project team;
• Facilitation of cross-government coordination and identification of areas where funding agencies could provide additional guidance or support—for example, when applying for a radio license or other regulatory requirements;
• Appropriate levels of management and oversight;
• More formalized means for community input to the agencies. For example, NASA’s Sounding Rocket Working Group is a possible model for this input;
• Evaluation of current access to space—for example, an assessment of time from selection to launch, launch success rates, availability of CubeSat Launch Initiative–supported launches and other potential opportunities for funding launches; and
• Appropriate levels of funding needed to maintain a robust program.

The increased costs of NASA MOs (see the next section) have created a gap in the funding between the current CubeSat funding level (~$4 million to $8 million) and the lower end of the MOs ($35 million). Missions in this gap could include larger balloon or rocket missions or multiple CubeSats—for example, for science requiring multipoint

measurements or larger suborbital launches. Similar gaps in the Astrophysics and Earth Science Divisions were recently filled with the new Pioneers Program and with Earth Venture instruments, respectively. The implications of this gap in Heliophysics should be considered, because such gaps affect program balance within NASA.

Recommendation 5-6: The National Aeronautics and Space Administration should create opportunities for principal investigator–led projects in the size range $10 million to $35 million (not including launch costs) that could accept higher risk than the Missions of Opportunity and be realized with minimal requirements for mission assurance and agency oversight.

This program could be implemented quickly and in a cost-effective manner if the Heliophysics Division partnered with or otherwise leveraged the approach of the Astrophysics Pioneers Program.

NOAA Space Weather Observations

The current NOAA missions monitor the Sun and the space environment, providing the data needed to make operative space weather forecasts and predictions. Future missions are designed to provide continuous monitoring of the Sun and the space environment well into the next decade (see Figure 5-9). These future missions include the Space Weather Follow-On Lagrange 1 (SWFO-L1) and Space Weather Next programs. There is substantial

international involvement in these missions. The SWFO-L1 mission, scheduled for launch in 2025, requires an international ground network for 24/7 mission data acquisition. A number of agreements are in place (Japan’s National Institute of Information Technology and Communications and Korea Radio Research Agency) or are being negotiated (South Africa and Brazil) to continue the Real Time Solar Wind network (RTSWnet) and supplement the SWFO antenna network. Discussions are under way with the Indian Space Research Organization to explore opportunities for collaboration—for example, data exchanges between SWFO-L1 and Aditya L-1. Space Weather Next program has multiple project components designed to extend space weather observations to a variety of critical vantage points: from L1 and L5 orbits, geostationary orbit, low Earth orbit (LEO), and ground support networks. NOAA’s National Environmental Satellite, Data, and Information Service (NESDIS) will provide a compact coronagraph to be hosted on ESA’s Vigil mission (2031 launch) and is exploring other instrument hosting opportunities with other international hosts, including the Canadian Space Agency, the Taiwan Space Agency, and the Korea AeroSpace Administration.

In addition to their primary monitoring task, these missions produce a wealth of data that support research space weather science and guide development of models used in forecasting and predicting space weather. It is important that NOAA develop systems to make those data readily available to the research community in a format that is compatible with other data sources.

While the decadal survey committee acknowledges and supports the NOAA satellite missions, it was not tasked with assessing the current and future monitoring missions or providing recommendations on their operational aspects. However, there are findings and recommendations of this decadal survey that focus on space weather research, the research to operations transfer, and the operations to research feedback (research to operations to research [R2O2R]). Space weather research and R2O2R pervades all solar and space physics, to the extent that it is included as a second part of the mission statement of this decadal survey—to serve humanity.

NASA Space Weather Program

The NASA Space Weather Program provides explicit transition of scientific knowledge to operational applications (see Figure 5-11). The Space Weather Program will provide a space weather science instrument on the ESA Vigil mission. Vigil (previously known as Lagrange) is an ESA space weather mission to observe the Sun from the Sun–Earth Lagrange point L5, away from the Sun–Earth line. This vantage point allows the propagation of coronal mass ejections emitted by the Sun toward Earth to be observed, as well as observations of the solar disk before it rotates into view from Earth. The Vigil mission will image the solar disk and corona as well as the inner heliosphere and measure the interplanetary medium at its location at 1 AU. The remote sensing instrument provided by the NASA Space Weather Program fills the gap between the Vigil photospheric magnetograph and the coronagraph provided by NOAA. The inclusion of a space weather monitoring instrument on a partner’s mission is a blueprint for future monitoring instruments onboard other NASA and international space missions.

As part of the Artemis program, the Lunar Gateway will be a Moon-orbiting outpost for astronauts heading to and from the lunar surface. Gateway will carry the Space Weather Program Heliophysics Environmental and Radiation Measurement Experiment Suite (HERMES), which consists of four instruments monitoring space weather conditions in lunar orbit. Similar to the space weather monitoring instrument on Vigil, HERMES has basic science goals and also provides observations that will be useful for space weather monitoring.¹¹ HERMES is a blueprint for deployment of future monitoring instruments, for projects under the auspices of the Moon to Mars strategy.

Given the increased need for space weather services in the coming decade, the NASA Space Weather Program needs to grow with fresh funding that does not come at the expense of the Heliophysics Division science. Specifically, funding for instruments that are vital for the safety of the lunar infrastructure and humans needs to be covered from sources outside the Heliophysics budget. In addition, if the Space Weather Program funding were sufficient, the program could fund model improvement efforts and analysis to demonstrate its operational effectiveness. The resulting techniques that showed sufficient improvement in forecasting and specification skill would then be candidates for transition to operations. As with the transition of instruments to operational status,

___________________

¹¹ This paragraph was modified after release of the report to accurately reflect the purpose of HERMES.

the transition of models to operational status requires close coordination with NOAA. This NASA and NOAA modeling effort is part of the larger R2O2R framework described in Section 3.3.1.

The Space Weather Program recommended for the next decade includes funding for a stand-alone mission up to the size of a SMEX as well as MOs. The program is designed to provide NASA with the means and flexibility to conduct stand-alone missions as needed. These missions would complement the Space Weather Program initiatives by providing demonstration instruments for missions carried out by other agencies and international partners. In keeping with the overall charter of the Space Weather Program, target objectives of these stand-alone missions need to be based on those observations or techniques that have been identified as showing promise for implementation as operational components of NOAA’s space-based fleet. NASA and NOAA need to work together to develop metrics and transition plans to transfer research results to NOAA operations, as recommended in Chapter 3 (see Recommendation 3-5).

The Panel on Space Weather Science and Applications (see Appendix E) reviewed the space weather value of all the missions that went through the evaluation (i.e., technical, risk, and cost evaluation [TRACE]) process (see Appendix G). The panel also suggested potential space weather enhancements for NASA missions. (See Chapter 3, Recommendation 3-6.) These add-ons range from enhanced data acquisition, modification of proposed instrumentation, to addition of space weather–related demonstration or even operational instrumentation. The panel review concluded that all new Heliophysics Division missions have the potential for space weather enhancements. Specifically, LEO satellites are ideal platforms to host GNSS receivers with upgraded firmware that enables total electron content (TEC) measurements, while medium Earth orbit (MEO) and highly elliptical orbit (HEO) satellites could host charge-discharge sensors. Orbits beyond Earth orbit are ideal for hosting sensors for measuring solar energetic particles. Space weather enhancements are best accommodated early in the mission development. Space weather is further discussed below.

Heliophysics System Observatory

The HSO comprises a wide range of space-based missions that are in its extended mission operations phase. Figure 5-8 contains the current HSO as part of the HSL but does not show the important contributions to the HSO from NOAA assets. Over the past decade, this observatory has grown in size and range of observations as many Explorer and larger-class missions have reached the end of their prime mission and have successfully completed senior reviews that emphasize new systems science objectives within the HSO. In fact, of the missions in Figure 5-8 that are currently in operation, only two, Parker Solar Probe (PSP) and Solar Orbiter, are in their prime mission phase. In addition, NASA has created and, in the 2023 senior review, greatly expanded a new infrastructure category for the HSO. The Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE), and Wind were a part of the original infrastructure category. Following the 2023 senior review, new infrastructure missions—Global-scale Observations of the Limb and Disk (GOLD), Hinode, Solar Dynamics Observatory (SDO), Solar Terrestrial Relations Observatory (STEREO), Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED), and Voyager—receive funding solely to continue operations for the next 3 years. In the future, these and the other infrastructure missions are invited to a programmatic review that is on a similar cadence as the senior review. The Interface Region Imaging Spectrograph (IRIS), THEMIS, Interstellar Boundary Explorer (IBEX), and Magnetospheric Multiscale Mission (MMS), which currently make up the rest of the HSO missions in extended operations, continue both operations and science. Additionally, NASA has been developing capabilities of the Heliophysics Digital Resource Library’s with an intent to integrate it into the management of the HSO mission data sets.

The combined fleet of infrastructure and science missions is considered as a single observatory, in effect a large-scale heterogeneous constellation. The value of the HSO in the previous decade was dramatically illustrated by numerous solar flare observations. Simultaneous observation by multiple HSO assets enabled major breakthroughs in the understanding of explosive energetic releases. For example, the flare on September 10, 2017, was simultaneously observed over the entire electromagnetic spectrum by NASA missions (SDO, IRIS, Reuven Ramaty High Energy Solar Spectroscopic Imager [RHESSI], Fermi), international spacecraft (SOHO, Hinode, Project for Onboard Autonomy 2 [PROBA2]), NOAA assets (Geostationary Operational Environmental Satellites

[GOES]/Solar Ultraviolet Imager [SUVI]), and ground-based observatories (EOVSA, Coronal Multi-Channel Polarimeter [CoMP], Low-Frequency Array [LOFAR]), and by ground-based neutron monitors. The multitude of observations measured the magnetic field strength along the current sheet, mapped out locations in the sheet where electrons were energized, and located the position within the current sheet where magnetic reconnection occurred and energy was released.

In the magnetosphere, fortuitous conjunctions of HSO spacecraft and NOAA assets offered glimpses of the highly complex magnetospheric dynamics, its response to various driving conditions, and highlighted the potential for future multispacecraft observations at various scales and in different regions. For example, a study involving GOES 13 and three THEMIS satellites found the first evidence that magnetic reconnection very close to Earth (near geosynchronous orbit, at 6.6–10 Earth radii [R_E]) could power intense geomagnetic storms. Another multispacecraft conjunction study using MMS, THEMIS, Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS), Van Allen Probes, and Cluster observations led to new understanding of the extreme thinning and stability properties of the magnetotail current sheet during active geomagnetic conditions. Simultaneous observations by Van Allen Probes, THEMIS, MMS, and GOES were used to probe the extreme variability of Earth’s outer radiation belt electrons, addressing the role of electron acceleration in the magnetotail as a possible source of outer belt electrons. These studies have made it clear that understanding the entire inter-connected system that makes up the magnetosphere, ionosphere, thermosphere, and mesosphere requires coordinated multiregion and multiscale observations.

For the systems science–focused themes of this decadal survey, constellation missions, new vantage points, and the HSO become critical elements of the research strategy. The distributed HSO has flexibility and capabilities that evolve with each new mission launched. Its current composition includes a significant number of diverse solar, heliospheric, and magnetospheric missions. However, with the loss of the Ionospheric Connection Explorer (ICON) spacecraft (after its highly successful prime and extended missions), there is a dearth of upper atmosphere (ITM) missions (see Figure 5-8). This shortcoming is remedied only when GDC and DYNAMIC are launched and included in the HSO near the end of the next decade.

NASA is actively engaged with the international community through HSO missions such as Hinode, IRIS, PSP, Solar Orbiter, Wind, SOHO, STEREO, MMS, and THEMIS. In the next decade, the importance of international missions in the HSO and the integrated HSL will continue to grow. Inner-heliospheric research takes on a much more international character with the inclusion of some important international missions, such as the BepiColombo dual-spacecraft mission to Mercury, and later in the survey interval, the Vigil and Solar-C missions observing the Sun and the solar wind. This international character could be strengthened even more if other space agencies, like the Indian Space Research Organization (ISRO) and the newly established Korean Aerospace Administration (KASA), are included in the HSL. The combination of these remote and in situ inner heliospheric measurements forms an unprecedented inner heliosphere observational capability in the next decade. Figure 5-10 illustrates the opportunities to measure the inner heliosphere either over a range of radial distances along a Parker spiral establishing a magnetic connection between the measurements (top panel) or a wide range of longitudes covering the global solar activity (bottom panel). The coordinated use of this fleet of spacecraft is a pathfinder for future science of the Sun and inner heliosphere—in particular, propagation of disturbances from the Sun to and beyond 1 AU.

Multiagency Support for Space Weather

While the NASA Heliophysics Division and NSF programs are focused on fundamental science and understanding of the local cosmos, space weather research is inseparably intertwined with the fundamental research.

Table 5-5 summarizes assets in the NSF, NOAA, and NASA programs of record (both operative and upcoming) and their space weather potential. The plans for ngGONG (see Section 5.2.2) include a space weather component from the planning of the infrastructure, while the other assets are scientific instruments that provide valuable space weather monitoring capabilities if the data are received and distributed to the users in a timely manner.

Earth’s high-latitude energy and momentum input resulting from coupling with solar wind and magnetosphere and DYNAMIC measures momentum and energy forcing resulting from coupling with the lower atmosphere through waves. In addition, GDC and DYNAMIC will trace the global energy and momentum transport through the ITM system and record the impacts on the global dynamical state of the system. These NASA observations will be made available in near real time to NOAA through optimized transmission content and latency for NOAA’s space weather notification system.

The near-real-time observations will contribute to space weather by (1) providing situation awareness data and space traffic management services to commercial space operators especially at LEO; (2) notifying operators providing communications, navigations, and surveillance services of the radio propagation conditions; (3) providing geomagnetic activity information to power grid and other system operators; and (4) monitoring the LEO radiation environment impacting spacecraft systems and human health.

As mentioned above, the Panel on Space Weather Science and Applications suggested space weather enhancements for NASA missions. These enhancements are significant because they provide a direct link between the NASA Heliophysics Division and the research to operations efforts of NASA and NOAA. Such enhancements

could also be included on NOAA operational missions as well as missions led by other federal agencies, given sufficient lead time in the mission development. Each additional datapoint in the sparse network is an important addition for space weather predictions; therefore, it is imperative to take advantage of all opportunities to increase the observational coverage. Each time an agency plans a new spacecraft or a ground-based facility, it would be advantageous to assess whether a space weather instrument, data stream, or other space weather component could add value at a reasonable cost. Instrument add-ons are best accommodated early in the mission development, which implies that it would be desirable to have an early space weather assessment as a standard practice by the agencies.

The NASA Explorer Program

The Explorer program is as old as NASA itself. The first U.S. satellite, Explorer 1, discovered Earth’s magnetosphere and radiation belts. Since then, the increased cadence and diversification of the mission classes has resulted in a program that responds rapidly and cost-effectively to science opportunities that evolve over the decadal survey intervals. The program has been an outstanding success, with missions that uniformly achieve their focused science objectives and provide major, new science results during their extended missions. The existing Explorers are critically important and cost-effective components to the HSO and hence the HSL. Truly, the Explorer program lives up to its name, providing exploratory science that paves the way for strategic missions. An outstanding, recent example is the IBEX SMEX, whose discoveries informed many of the science objectives for the strategic STP IMAP mission.

Explorer solicitations, even though the announcements of opportunity (AOs) are not the same (Stand Alone MO Notice Program Element Appendix versus standard AO), and the evaluation panels are different. Concurrent solicitations potentially disadvantage institutions that lack the resources to produce multiple proposals simultaneously, forcing proposers from these institutions to choose between proposing a MO and a full mission. The concurrent solicitations can have the effect of reducing the quantity and competitiveness of the MO proposals. This could have contributed to no MO being selected in the recent SMEX 2022 cycle.

At the upper end of the cost scale for the current Explorer program, the MIDEX missions offer an excellent opportunity to perform important science on a budget that falls between the SMEX budget and the strategic LWS and STP missions budgets. However, the current structure, implementation, and cost caps of the Explorer program are not conducive to launching the constellations of spacecraft needed for reaching the science goals of the next decade. The current Explorers cost cap and offered launch options limit constellations to ~10 CubeSats and a single launch. An increase in the MIDEX cost cap from $250 million to $300 million, as assumed for the next decade (see Chapter 6), does not substantially reduce these limitations. Furthermore, the current definitions and implementation of risk class and reliability focus on single flight systems or small constellations, which makes it difficult for constellation missions to compete against other missions in the current Explorer program. New approaches are needed to facilitate efficient operations and maintenance of these large constellations. Increased use of autonomy may be necessary to manage large constellations, in addition to new approaches to communications, including increased use of commercial providers or inter-satellite crosslinks. While the current cost caps limit the number of spacecraft in a constellation, there are other viable Explorer missions (small constellations of larger spacecraft and single spacecraft) that could fit within the cap.

Conclusion: Multipoint science observations and system science are the next frontier in heliophysics. Implementing large satellite constellations (≥24 satellites), as submitted in many community input papers to this decadal survey, is not feasible in the current Heliophysics Division–competed (PI-led) mission portfolios.

Conclusion: There is currently a significant gap in funding between MIDEX and the recommended strategic LWS and STP missions. This gap needs to be filled to maintain program cost balance across the Heliophysics Division.

These conclusions drive the following recommendations for necessary revisions to the Explorer program. These revisions are designed to enhance the effectiveness of an already extremely successful program and enhance accommodation of constellation missions. They clarify the recommended Explorer cadence, the association between Explorers and MOs, and add a new class to the Explorer program to fill an increased mission cost gap between the MIDEX missions and the strategic LWS and STP missions. Specifically, the addition of a new class of Explorers arises from the critical need for moderate-scale constellation missions.

by determining the combinations of fundamental processes (Section 2.2) that build up the complex dynamics between the solar wind and Earth’s coupled magnetosphere–ionosphere systems (Section 2.1). The foundational understanding from a mission like Links may help assess the habitability of exoplanets (Section 2.3) as well as to build next-generation space weather applications (Chapter 3).

This bold constellation mission concept comprises two platforms for auroral and magnetospheric imaging along with 24 satellites making in situ observations in the magnetosphere. The auroral imagers provide unprecedented simultaneous coverage of the northern and southern auroral ovals, unraveling questions related to (a)symmetries between the two hemispheres. The magnetospheric imagers provide the first-ever portrayal of the tenuous plasma system engulfing Earth, as the fleet of 24 satellites resolve for the first time the striated plasma flows and structured magnetic fields providing ground truth for the global imagers (Figure 5-13).

The simultaneous conjugate auroral observations from the two hemispheres are provided by spacecraft in circular polar orbits that view both the auroral oval and the magnetotail transition region near the equatorial plane. The high (~20 km) spatial resolution of the imagers resolves the meso-scale auroral dynamics and energy deposition that close an important gap in the global energy circulation process. The dual imager system reveals asymmetries in energy deposition and auroral processes between the two poles, and how such asymmetries between the poles impact the magnetotail processes.

Each imaging spacecraft carries three energetic neutral atom (ENA) imagers that provide remote sensing observations of the magnetospheric ion populations. These images reveal for the first time the shapes, sizes, velocities, and pathways of these dynamic structures that are the main carriers of energy from the outer magnetosphere inward. The composition and spectral information define the role of ionospheric sources in magnetic storm processes.

This ground-breaking constellation will be the first ever to resolve magnetotail dynamics simultaneously along and across the magnetotail, allowing the spatial structure and the temporal evolution to be uncovered at the same time. The in situ satellites have mesoscale (0.5–1 R_E) spacing near their apogees, designed to resolve the flow channels and the associated magnetic flux bundles and filamentary current systems in the magnetotail as well as transient phenomena within and around the bow shock and dayside magnetopause. Each in situ spacecraft carries

an instrument suite consisting of ion and electron plasma and energetic particle detectors and a magnetometer, enabling measurements of high-speed plasma flows, particle injections, magnetic field dipolarizations, and dayside transient plasma and magnetic field structures.

The notional Links mission responds to the primary objective of the STP mission line, to “understand fundamental physics processes from the Sun to Earth” with its scientific objective to determine the mass, momentum, and energy flow in the magnetosphere. It will advance understanding of the cross-scale and cross-regional coupling that directly feeds to broad scientific progress with applications beyond the terrestrial space environment. It is also expected to pinpoint key processes in the coupled system dynamics at Earth, thus its discoveries will enable operational space weather prediction and forecast models to take major leaps forward. As with all STP missions, Links would benefit greatly from international participation.

More details of this constellation-class mission are provided in the report of the Panel on the Physics of Magnetospheres in Appendix C. The cost information from the TRACE process for this mission is provided in Chapter 6 and Appendix G.

Recommendation 5-8: The highest priority for a new Solar Terrestrial Probes mission is one to investigate the system-level global coupling between the solar wind, magnetosphere, and ionosphere, while resolving mesoscale dynamics. This requires a heterogenous constellation mission that includes in situ measurements and remote sensing. If a science and technology definition team study is appropriate for the implementation, then it should be done early in the decadal survey interval in time to support development starting in fiscal year 2027.

Highest-Priority New Living With a Star Mission: Solar Polar Orbiter

The highest-priority new LWS mission for the next decade is a mission that focuses on the Sun’s poles. The notional mission that underwent the TRACE process was the Solar Polar Orbiter (SPO), shown schematically in Figure 5-14.

SPO is an ambitious mission concept to image the Sun from a completely new place to answer fundamental questions about how the Sun generates its magnetic field and how the field drives solar activity and shapes the heliosphere over the course of the solar activity cycle. The SPO would be the first mission to image the extended polar regions of the Sun, focusing on the solar magnetic fields. Historically, solar observations have been made from the ecliptic plane (on which Earth orbits the Sun) and most often from the Sun–Earth line. ESA’s Solar Orbiter is a notable exception, but even its measurements are limited to relatively small out-of-the-ecliptic viewing angles. The polar regions are key to understanding the cyclic behavior of solar activity and these regions are observable only from a high-inclination vantage point.

A mission to observe the solar poles is needed to establish how the Sun’s differential rotation evolves from the equator to the poles, how the plasma convects at and near the poles, and what the strength and distribution of the magnetic field is at and near the poles. These measurements are critically important to constrain models of the solar magnetic dynamo and to understand the time-variable extension of the solar magnetic field into the interplanetary medium. SPO builds on results from previous missions. The Ulysses mission made several passes above the solar polar regions and recorded the solar cycle variability of the solar wind and magnetic field structures at high solar latitudes. However, focused on in situ observations, Ulysses did not resolve the solar sources of these fields and flows. While ESA’s Solar Orbiter will eventually observe from a vantage point that is as much as 30° out of the ecliptic, it does not provide the kind of sustained observations necessary to make significant progress on these questions. Furthermore, SPO imagery provides an entirely new perspective on the corona and heliosphere by observing from well above the ecliptic plane. For example, SPO can determine the longitudinal structure of the streamer belt, radial and longitudinal extent of solar eruptions, and the longitudinal origins of fast solar wind streams.

SPO makes progress on all the science themes described in Chapter 2. By revealing details and variability of the magnetic fields at the solar poles, SPO data helps uncover the “solar magnetic field through the heliosphere” (Section 2.1). The SPO observations are crucial for the guiding question, “How is the Sun’s global magnetic field created and maintained, and what causes its cyclical variations?” (Section 2.2). The SPO mission contributes to

“exploration of new environments” (Section 2.3), as very little is known of the dynamics of the solar poles. Prior missions to the giant planets have shown beautiful vortices such as those in the Jovian polar regions (Juno) and an intriguing hexagonal jet stream at Saturn’s poles (Cassini). If such vortices or jets were found at the Sun’s poles, they would likely play a critical role in determining the generation of magnetic fields in the Sun. As the solar magnetic field structure is the key driver for space weather (Chapter 3), the SPO mission has direct relevance for understanding long-term space climate evolution.

SPO responds to the primary objective of the LWS mission line, to “provide scientific understanding that leads to predictive capability.” Specifically, the space weather advancements come through recording the first polar magnetograms over multiple solar rotations and simultaneous 360° longitudinal views of coronal structure, variability, and coronal mass ejections (CMEs). The comprehensive suite of instrumentation on SPO includes a compact doppler magnetograph, extreme ultraviolet (EUV) imager, white light coronagraph, ion electron spectrometer, ion mass spectrometer, heliospheric imager, and an energetic particle suite. The spacecraft uses planetary gravity assists to achieve a 3-year orbit that is >70 degrees out of the ecliptic plane, allowing extended periods of unobstructed observation of both the northern and southern solar poles. The mission lifetime spans at least one solar activity cycle. As with all LWS missions, SPO would benefit greatly from international participation.

More details of this out-of-the-ecliptic mission are provided in the report of the Panel on the Physics of the Sun and Heliosphere in Appendix B. Cost information from the TRACE process for SPO is provided in Chapter 6.

Recommendation 5-9: The highest priority for a new National Aeronautics and Space Administration Living With a Star mission is one to explore the solar polar regions to understand how polar magnetic fields and flows reveal the Sun’s global dynamics and the mechanisms that underlie the solar dynamo and shape the solar activity cycle. A science and technology definition team study should be completed by approximately the middle of the decadal interval (i.e., before fiscal year [FY] 2029) in time to support mission development starting in FY 2029.

NOTE: The color scheme matches the color scheme for the science questions in Figure S-1.

___________________

¹² The 2013 solar and space physics decadal survey recommended, “implementation of a new, integrated, multiagency initiative (DRIVE—Diversify, Realize, Integrate, Venture, Educate) that will develop more fully and employ more effectively the many experimental and theoretical assets at NASA, NSF, and other agencies” (NRC 2013, p. 77).

CubeSat programs, in addition to providing valuable data for science, are essential for providing hands-on training opportunities (Section 5.3.4). Materials to support future mission leaders are provided by the NASA SMD list of resources for PIs¹³ and the PI LaunchPad Workshops, which were initiated in 2019 to provide better access and training for aspiring mission PIs.

Chapter 4 discusses the current state of the profession and includes recommendations for ensuring a sustainable workforce that meets evolving basic research and space weather needs. Those recommendations that fall into the DRIVE+ framework include the following: Recommendation 4-2, which details how the funding agencies can expand the reach of space physics in education to recruit students from diverse areas of study; Recommendation 4-3, which asks NSF to continue and expand support for the Faculty Development in geoSpace Science (FDSS) program in solar and space physics at colleges and universities; and Recommendation 4-4, which asks funding agencies to increase opportunities for researchers to lead summer schools, workshops, and other skill-building activities for undergraduate and graduate students.

5.3.2 Collaboration and Coordination

Different aspects of solar and space physics research are supported by different agencies, reflecting its interdisciplinary nature and the diverse types of data and tools required to advance the science. The integration of heterogeneous data sets and models, and the cross-divisional and cross-agency coordination required to enable it, are essential for addressing the science goals and space weather needs of the next decade.

Space Weather

Cross-agency collaboration in the field of space weather has advanced significantly; however, the December 2023 memorandum of agreement between agencies is a positive step, but needs to be followed by action (Section 3.3). Areas where further coordination would lead to a better use of resources, and improved outcomes, were identified in Chapter 3 and are not repeated here. However, the committee emphasizes the importance of space weather research priorities being informed by user-driven needs and outcomes. The space weather research recommendations relevant to DRIVE+ include the following: Recommendation 3-2 to NOAA and DoD to identify high-priority space weather research goals and develop processes to ensure communication of these priorities across NASA, NSF, NOAA, and DoD-DAF; Recommendation 3-3, which asks NASA and NSF to target their research programs to these prioritized research goals; and Recommendation 3-4 to NOAA to establish a space weather research program and partner with DoD to develop large-scale predictive space weather models that can meet the operational demands.

Combining Ground- and Space-Based Data Sets

Community interest in expanding, coordinating, or integrating instrument networks in support of systems science has been steadily increasing. Improvements in coordination are needed to make significant progress toward decadal science goals. For example, now that Inouye is online, good coordination between NSF and NASA is critical for realizing the scientific potential of combining ground- and space-based observations across the spectrum and in situ. The recent ISTP-Next report that grew out of a community-led grassroots effort expresses the coordination needs by stating that “the current uncoordinated and oftentimes fractured observational, analysis, and modeling activities are incompatible with the holistic system-of-systems approach that is needed to answer many of the outstanding science questions of this era” (ISTP-Next 2023). Recommendation 5-1 addresses the need for agencies to coordinate development and operations of ground- and space-based assets through strategic management of an integrated HSL. This is necessary but not sufficient; after the HSL data are collected, research support for their combined analysis is needed to turn data into scientific results.

Systems science methodology emphasizes a close integration of ground- and space-based assets because they observe different aspects of a single phenomenon. Use cases abound but with differing emphasis depending on

___________________

¹³ “New Principal Investigator (PI) Resources,” for Researchers, NASA, https://science.nasa.gov/researchers/new-pi-resources, accessed June 2, 2024.

subdiscipline. For instance, solar physics requires comprehensive remote sensing observations across the electromagnetic spectrum, as well as in situ observations of particles and fields, from multiple vantage points.

ITM and magnetospheric studies demand a combined data set registered to common coordinates. Data returned from space missions and ground-based facilities are currently managed by different agencies, or different directorates within an agency (e.g., at NSF). As a result, data formats and other aspects of archiving and distribution are not handled uniformly. Furthermore, the agencies prioritize different data sets in their strategies and decision-making. This creates artificial barriers and unnecessary risk at the proposal phase, in particular, to projects that seek a tight integration of space- and ground-based observations at the mission planning phase.

Agencies have started to recognize that combined assets can be more than the sum of their parts and are making efforts to improve coordination, such as NASA’s HSO with data accessible through the Space Physics Data Facility (SPDF). NSF has invested in enabling joint analysis of ground magnetometers through the SuperMAG facility as well as the combined use of the individual SuperDARN radars. The HSL proposed in this decadal survey is the first attempt to bring together observations from heterogeneous sources and multiple platforms, essential for continued scientific progress.

Despite these positive steps, increased and sustained coordination will be required to achieve measurable progress in the identified research focus areas for the coming decade. This calls for new innovative approaches to obtaining, accessing, and analyzing diverse data sets. Recommendation 5-1 for an integrated HSL addresses the need for coordinated observations. Additional measures are needed to make scientific progress using these data.

Conclusion: Data analysis that combines ground- and space-based observations is essential for scientific advances in solar and space physics. Coordination among federal agencies (NASA, NSF, NOAA, and Air Force-AFOSR) is needed to enable data access and sharing of tools in a seamless and efficient way. Continued barriers to this kind of coordination limit scientific progress.

Recommendation 5-10: The National Aeronautics and Space Administration (NASA) and the National Science Foundation (NSF) should expand and coordinate opportunities for carrying out scientific research that combines ground- and space-based observations. Grant funding opportunities should continue to enable and enhance joint analysis of ground-space data as appropriate. NSF and NASA should offer additional funding opportunities that support joint aggregation, assimilation, and analysis of ground- and space-based data and production and archiving of combined ground-space data products.

Cyberinfrastructure and Data-Driven Discovery

The explosive growth of data and computing capabilities over the past decade have ushered in a new era of data-driven discovery, impacting all areas of science, technology, and society. The integration of data science methods (e.g., AI, machine learning, big data, deep learning) into solar and space physics is rapidly changing the way researchers approach scientific discovery. This trend is only expected to accelerate in the coming decade with the proliferation of multipoint ground- and space-based measurements, remote sensing, and supercomputer simulations producing enormous amounts of data. These advances make it imperative for the solar and space physics community to develop a sustained cyberinfrastructure (“the hardware, software, networks, data and people that underpin today’s advanced information technology”¹⁴) for collection, storage, and shared analysis of disparate data sets.

The community has started organizing at the grassroots level to respond to these challenges, while NASA and NSF have launched strategic programs to embrace and capitalize on this cultural shift.¹⁵ NASA’s Open

___________________

¹⁴ “Cyberinfrastructure and Advanced Computing,” Our Focus Areas, National Science Foundation, https://new.nsf.gov/focus-areas/cyberinfrastructure, accessed June 2, 2024.

¹⁵ “Workshop for Collaborative and Open-Source Science Data Systems,” Meetings, Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, https://lasp.colorado.edu/meetings/sds-workshop, accessed June 2, 2024. “IHDEA and DASH Hybrid Meeting 14-18 October 2024,” International Heliophysics Data Environment Alliance, https://www.cosmos.esa.int/web/ihdea/ihdea-dash-2024, accessed June 2, 2024. “Python in Heliophysics Community,” PyHC, https://heliopython.org, accessed June 2, 2024.

Source Science initiative¹⁶ endeavors to make publicly funded scientific research transparent, inclusive, accessible, and reproducible. Within the initiative, NASA has instituted a 5-year Transform to Open Science (TOPS) program dedicated to establishing a robust infrastructure to train scientists and researchers on the critical definitions, tools, and resources underpinning the open science culture and to provide participants at all career levels with recommendations on best practices. Since 2017, NSF has embraced “10 Big Ideas” to “define a set of cutting-edge research agendas and processes that are uniquely suited for NSF’s broad portfolio of investments, and will require collaborations with industry, private foundations, other agencies, science academies and societies, and universities.”¹⁷

Among the Big Ideas is “Harnessing the Data Revolution,” which seeks to engage NSF’s research community in the pursuit of fundamental research in data science and engineering. This is realized through three principal components: research that seeks convergence across NSF directorates, educational pathways that support a data science–literate workforce, and advanced cyberinfrastructure to accelerate data-intensive research.

The solar and space physics community can build on this Big Idea through a coordinated strategy among NASA Heliophysics Division, NSF Geospace Section, NSF Division of Astronomical Sciences, and relevant parts of NOAA. With an increasing emphasis on systems science in the next decade, combined use of data from all sources with efficient means to access and process it will become crucial. This includes combining ground- and space-based; scientific, operational, and commercial; solar, heliospheric, magnetospheric, and upper atmospheric observations to describe the entire heliospheric system of systems. Such a common, sustained cyberinfrastructure, providing a single point of entry to all solar and space physics data for the entire community, is critical and would serve multiple inter-related purposes.

NASA’s Heliophysics Division has done a commendable job in collecting observations from the HSO into a common SPDF and Solar Data Analysis Center (SDAC), open to all researchers. However, this system needs a major update to ingest vastly increased data volumes and to provide modern tools that enable combined analysis of heterogeneous data sources. For example, sophisticated search engines that facilitate finding multimessenger coordinated data of specific events is not something that SDAC currently allows. In addition, solar and space physics scientific observations are being augmented by a fleet of satellites operated by NOAA (e.g., the Polar Operational Environmental Satellites [POES] and DSCOVR), other government organizations, and private industries. While many of these organizations are willing and able to provide data for scientific use, there is no coordinated activity to bring those data to formats and platforms easily usable by the research community.

Furthermore, ground-based infrastructure to monitor space and the upper atmosphere has a variety of ownership and operational models. While some data are collected to common databases (e.g., the NSF-funded SuperMAG ground-based magnetometer data collection facility, the SuperDARN radar network data distribution system, AMPERE LEO magnetometer data facility, and the Virtual Solar Observatory [VSO]), there is no coordination or resourcing to bring these assets to a common framework. This results in wasted time and resources when individual researchers repeat data collection and processing tasks and limits the use of these valuable data in studies addressing systems science questions. Resolving these challenges at NSF will require coordination across NSF directorates, including the MPS Division of Astronomical Sciences (AST) (solar) and the GEO Division of Atmospheric and Geospace Sciences (geospace).

While it may not be feasible to build a single data repository with all data, it is feasible to build a common cloud-enabled cyberinfrastructure that links to existing data sources. Cloud resources will enable the analysis to be done where the data reside, eliminating the need to move around large volumes of data. Projects such as HelioCloud¹⁸ are already enabling such functionality, albeit with a limited scope. Such efforts need to be scaled up to include disparate observational and modeling data sets from across solar and space physics.

___________________

¹⁶ “Open Science at NASA,” Science, NASA, https://science.nasa.gov/open-science, updated May 31, 2024.

¹⁷ “10 Big Ideas for Future NSF Investments,” National Science Foundation, https://scepscor.org/documents/nsf_big_ideas.pdf, accessed June 2, 2024; and “NSF’s 10 Big Ideas,” Special Report, National Science Foundation, https://www.nsf.gov/news/special_reports/big_ideas, accessed June 2, 2024.

¹⁸ “Cloud Software for the Heliophysics Research Community,” HelioCloud, https://heliocloud.org, accessed June 2, 2024.

tion (Astrophysics Division) and planetary magnetospheres and upper atmospheres (Planetary and Earth Sciences Divisions) (Figure 5-16). Opportunities for cross-divisional collaboration on missions and technologies are further discussed in Section 5.4.

NASA has recognized the need for multi-, cross-, and transdisciplinary research to address critical heliophysics science goals. As one example, the 2018 announcement of opportunity for Heliophysics Phase I DSCs addressed this as a central theme, calling for centers to “play a major role in enabling interdisciplinary science and innovative approaches.. . . Create a rich environment that provides valuable research and educational experiences for the broader community.”¹⁹ Recognizing the importance of the multidisciplinary characteristics of successful DSCs, proposers were expected to include a “talented, diverse, multi/inter/trans-disciplinary, and fully integrated team to execute the research program.” These centers are already expanding the traditional sub-disciplinary boundaries within the Heliophysics Division, which has resulted in major scientific advances and novel methodology developments—for example, the ongoing development of the Multiscale Atmosphere–Geospace Environment (MAGE) model now available to the broader community via the NASA Community Coordinated Modeling Center (CCMC).²⁰

Space weather research is also inherently interdisciplinary, because it covers the full chain of processes occurring from the Sun, through interplanetary space, to planetary magnetospheres and upper atmospheres, as well as the impacts on humans and technological systems in space and on the ground. The Space Weather Centers of Excellence selected in 2023 combine expertise from a broad range of solar and space physics, and in many cases, also from the AI and machine learning research communities. These investments expand the solar and space physics community into the information sciences area and foster engagement with organizations developing or using the space weather information (e.g., NOAA, companies developing space weather products, and the space weather user community).

___________________

¹⁹ “Amendment 24: DRAFT B.13 DRIVE Science Center Call Released for Community Comment.” NASA Science Research website, https://science.nasa.gov/science-research/for-researchers/roses/amendment-24-draft-b13-drive-science-center-call-released-community-comment, updated May 22, 2023.

²⁰ “MAGE.” Model Catalog, Community Coordinated Modeling Center, https://ccmc.gsfc.nasa.gov/models/MAGE~0.75, accessed June 2, 2024.

transdisciplinary research spanning areas that are outside the field of space science, connecting space plasma research to that of laboratory plasmas and energy production; theory and modeling in solar and space physics with mathematical, statistical, computational, and information sciences; and, as an emerging topic, connecting NSF’s basic research endeavors with the applied field of space weather. NSF has been proactive in supporting multidisciplinary efforts—for example, through a variety of space weather calls and by enabling community-organized efforts such as the Comparative Planetary Magnetospheres focus group mentioned above. Nevertheless, some areas of research near the boundaries can fall through the cracks, such as outer heliosphere and planetary sciences, neither of which seem to find a home in either geosciences or solar physics.

Although these opportunities for expansion are valuable and would benefit the entire scientific community, it is important that these efforts to not take resources away from the core of solar and space physics research because there are still critical unanswered questions about the heliosphere and the basic physical processes at play.

Support by multiple divisions at the NSF (see Box 5-2) has sometimes been advantageous to solar and space physics. For example, funding is available from multiple NSF divisions for both researchers and different institutes, offering more diverse opportunities. Inouye is an excellent example of a major research facility that was supported both by AST and GEO. On the other hand, there may be significant benefits in consolidating solar, heliospheric, space physics, and space weather science within a single division. These include the ability to develop and enable a single strategic vision, better advocate for solar and space physics within NSF, enable better integration between ground-based facilities and programs, provide better interfaces to other space- and ground-based “system components,” enable efficiencies and opportunities in proposal submission and review, and enable a single NSF entity to coordinate with other agencies and to provide a consolidated interface to national and international space weather science.

The 2013 decadal survey and its midterm assessment highlighted challenges related to the fragmented organizational structures at NSF, and those have become even more pressing in recent years. The astronomy and astrophysics decadal surveys have historically provided recommendations to AST for ground-based solar physics. However, in 2020, the astronomy and astrophysics decadal survey narrowed its scope to solar physics done in the service of astronomy. Thus, the AST division needs to respond to two decadal surveys (astronomy and astrophysics, solar and space physics), released at different times, to fully serve the solar community.

Additionally, as discussed in Chapter 4, there are challenges associated with identifying members of the solar and space physics community, and thus in obtaining accurate demographic information of the profession. Different terminology used by NASA (Heliophysics) and NSF (Geosciences and Astronomical Sciences) causes confusion in communicating the science to a broad audience and leaves solar and space physics without a clear identity in the public mind (e.g., the solar eclipse of 2024 was mostly identified as an astronomical event by the press). The different organizational structures can leave gap areas and make it more difficult to coordinate across agencies, especially in areas that deal with systems science problems spanning a broad range of disciplines. The new space weather mandate for the NSF (see Chapter 3) is at an institutional level, encompassing multiple divisions, which makes it more challenging to identify a clear point of contact.

___________________

²¹ Definition from NASA, 2023, “2023 Heliophysics Senior Review Call for Proposals,” https://lasp.colorado.edu/galaxy/download/attachments/1900656/2023%20Heliophysics%20Senior%20Review%20Call%20For%20Proposals%20FINAL.pdf.

which scientific analysis can be supported by the mission funding (see also the 2024 Heliophysics Advisory Committee Report [NASA 2024b], which includes findings and recommendations on this topic), because part of data validation is always achieved through scientific analysis. These decisions communicate NASA’s prioritization of science carried out by the broader research community rather than by the mission science team (Leisner 2024). While engagement of the broader community through guest investigator programs is commendable and expands the reach of each mission, it is essential to involve the mission science teams who understand instrument operations and can validate the data. Early career researchers often play an integral role in producing and validating mission data products; their participation is enabled by mission funding that also supports their own scientific research, necessary for advancing their careers.

Recommendation 5-14: For missions that are moved to the infrastructure category, the National Aeronautics and Space Administration should ensure that sufficient funding is provided for mission teams to calibrate and process data to Level 2 (calibrated data products that are in physical units, appropriate for use by the rest of the science community), deliver to the Space Physics Data Facility, and carry out scientific validation.

Realizing the Scientific Potential of Archival Data

In addition to the increased number of infrastructure missions for which scientific data analysis is not supported as part of the mission funding, some Heliophysics Division missions have ended their operations. These include Imager for Magnetopause-to-Aurora Global Exploration (IMAGE 2000–2005), Van Allen Probes (2012–2019) and its supporting BARREL balloon project (2013–2020), RHESSI small explorer (2002–2018), and ICON, which achieved full mission success at the completion of its primary mission (2019–2022). Together with the other integrated HSL components, significant amounts of high-quality data produced by these missions would form a valuable part of the HSL archive.

As many of the (combinations of) observations from the past and presently operative missions form unique data sets that will not be available in the foreseeable future, there is an acute need for program elements that support the analysis of archival data. This is important for both basic science research and space weather research. Recommendation 3-4 proposes that NOAA establish a new space weather research program that could support such analysis. At NASA, the HGIO program only supports analysis of currently operating missions, while the Heliophysics Supporting Research (HSR) program element encourages projects that combine data analysis with a theory or modeling component. While the combination of observation and theory/modeling is not strictly required, NASA has communicated—and the community broadly believes—that proposals not including both elements have lower priority for selection. A NASA presentation to HPAC in February 2024 stated as follows:

___________________

²² See, for example, Nietzel (2022).

___________________

²³ The new NCAR Derecho supercomputer, with nearly 20 petaflops peak performance, entered production at the beginning of 2024.

²⁴ “November 2023,” Lists, TOP500, https://www.top500.org/lists/top500/2023/11, updated November 2023.

___________________

²⁵ “Amendment 5: Final Text and Due Dates for B.15 the Geospace Dynamics Constellation Interdisciplinary Scientists Program,” NASA Science for Researchers, https://science.nasa.gov/researchers/solicitations/roses-2021/amendment-5-final-text-and-due-dates-b15-geospace-dynamics-constellation-interdisciplinary, updated September 11, 2023.

Excellence program was implemented even later, and there is a similar expectation of lessons learned by the time of the midterm assessment.

While different agencies may have different constraints, the DSC program would benefit from enhanced collaboration between NASA and NSF. Potential NSF contributions could be involvement by NSF facilities (e.g., by providing expertise on data usage) or by leveraging NSF’s strengths in broadening impacts activities.

Recommendation 5-18: To ensure their continued success, the National Aeronautics and Space Administration should review the structure of DRIVE Science Centers program and Space Weather Centers of Excellence program around the time of the midterm assessment. This could be either in conjunction with the midterm assessment or as a separate study feeding into the midterm assessment.

Laboratory Space Plasma Advancing Solar and Space Physics

Laboratory plasma physics has made useful contributions to understanding of space plasmas. Several laboratory experiments have facilitated comparisons with solar and heliophysics conditions, enabling direct comparisons with solar and space physics observations and models. Several laboratories were at the forefront of this effort; the Line-Tied Reconnection Experiment (LTRX) plasma physics facility at the University of Wisconsin, Madison, was built to investigate ideal and resistive magnetohydrodynamic instabilities for various boundary conditions and equilibria. This experiment is suitable for solar physics because the boundary conditions are similar to those in the solar atmosphere. The Facility for Laboratory Reconnection Experiments (FLARE) at the Princeton Plasma Physics Laboratory (PPPL) is an intermediate collaborative user facility whose focus is on magnetic reconnection processes.²⁶ The Basic Plasma Science Facility (BAPSF) at the University of California, Los Angeles, is a national facility for fundamental plasma science sponsored by DOE and NSF. BAPSF, and its primary experimental device, the Large Plasma Device (LAPD), provide a platform for studying processes such as plasma waves, collisionless shocks, magnetic reconnection, wave-particle interactions, and turbulence. The Naval Research Laboratory uses the Office of Naval Research (ONR)-sponsored Space Physics Simulation Chamber (SPSC) to complement theory, modeling, and in situ space measurements with laboratory experiments. Often laboratory experiments cannot fully match the relevant parameters and conditions of heliophysics systems. T&M can help connect laboratory experiments with the actual system. SPSC allows for collaborative investigations of space plasma physics under controlled, reproducible, scaled laboratory conditions, suited particularly well to problems addressing the near-Earth space plasma environment. SPSC provides a reasonably realistic testbed facility for the development and preflight testing of space diagnostics and hardware.

In addition to laboratory facilities that explore elements of basic plasma physical phenomena, spectroscopic diagnostics is an important means to determine the physical conditions in solar and heliospheric plasmas. Models of optically thin radiation rely on atomic cross-sections, ionization/recombination rates, electron excitation rates, and radiative decay rates calculated theoretically and validated against laboratory data. Two major resources used for space applications include the CHIANTI atomic database²⁷ for emission lines for calculating spectra from astrophysical plasmas and the Atomic Data and Analysis Structure (ADAS), which is an interconnected set of computer codes and data collections for modeling the radiative properties of ions and atoms in solar and heliospheric plasmas. However, even though many solar and heliospheric plasmas include very heavy elements, the available databases lack essential data on these elements, and existing codes cannot treat these elements. Benchmarking of atomic data models requires new, high-resolution laboratory spectrometers in the ultraviolet (UV) and X-ray wavelength regions as well as adequate funding for maintaining and updating production codes and databases.

___________________

²⁶ FLARE was constructed by a consortium of five universities (Princeton University; University of California, Berkeley; University of California, Los Angeles; University of Maryland; University of Wisconsin–Madison) and two DOE national laboratories (PPPL and Los Alamos National Laboratory).

²⁷ “CHIANTI,” CHIANTI Database, https://www.chiantidatabase.org, accessed June 2, 2024.

and eventually on future flight missions. Recognizing that new technology development efforts are not always successful, the recent H-TIDeS solicitations strongly encourage high-risk/high-impact concepts, which the decadal survey committee endorses.

After the potential of new instrument concepts has been demonstrated, opportunities to raise the technology readiness level (TRL, a scale from 1 to 9, with TRL 1–2 being basic technology research, TRL 6—technology demonstration in a relevant environment, and TRL 9—flight proven) are provided by NASA’s suborbital and CubeSat programs as well as through technology demonstration options (TDOs) on larger missions. These are described below and in Section 5.4. Results from the TRACE analysis of proposed mission concepts highlighted the healthy technology infusion roadmap of NASA’s technology programs, as several prior CubeSat instruments were proposed for the STP and LWS mission concepts. However, the analysis also revealed that some of these instruments may still need significant design modifications and test updates before they qualify for larger-scale, longer-duration science missions with more stressing operational requirements.

The need for multipoint measurements is a theme that emerged from the mission concepts introduced in the community input papers to this decadal survey and were further developed by the panels to address priority science. Many of the mission concepts involve heterogeneous constellations, which comprise several types of measurements made from different vantage points. The implementation of such constellations often involves nonidentical spacecraft and multiple launches. Examples include the prioritized Links notional mission (see Section 5.2) and a host of other concepts that were studied (see Appendixes C, D, and G). Furthermore, building and calibrating the instruments for a large constellation of dozens or more satellites required by some of the concepts requires new processes and capabilities.

The past few years have witnessed an explosion in the number of commercial satellites, many of which are part of mega-constellations for communications (i.e., Internet in space). The increasing number of commercial satellites could mean an increase in opportunities for hosted payloads, providing another means for obtaining multipoint measurements. In a panel discussion hosted by the “Access to Space” working group of this decadal survey, representatives from the commercial sector were unanimously willing to work with the science community to implement hosted scientific payloads onboard commercial spacecraft. However, they also indicated that including hosted payloads is commercially viable only if instruments are hosted on hundreds of their satellites and conform to existing bus resource capabilities. Such resource limitations currently preclude field of view and pointing requirements assumed for many ITM instrument concepts (see Appendix D). Even for instruments with less stringent accommodation requirements, the nonrecurring engineering costs are too high to host only a handful of instruments. The system science goals provide an obvious use case for hundreds of hosted sensors, but the capability to build that many copies of science instruments does not currently exist.

In 2020, NASA established a centrally managed SMD rideshare office to develop standard rideshare processes, provide a single interface between NASA and rideshare providers, and to maximize science return of rideshare opportunities (Mendoza-Hill 2021). This positive step toward improving coordination and identifying rides for heliophysics instruments was taken in response to the report Agile Responses to Short-Notice Rideshare Opportunities for the NASA Heliophysics Division (NASEM 2020b) However, the TRACE analysis identified several challenges regarding building multiple high-precision science instruments and pointed out that the limiting factor is the instruments rather than the satellite bus. Building instruments en masse may require instrument technology licensing to multiple providers to enable rapid production through parallel builds. Managing multiple providers requires additional systems engineering and management. Because science instruments are often highly specialized, there may be only a few potential providers, and careful consideration is also needed for science-unique requirements and characteristics such as EMI and magnetic cleanliness, spinning platforms, relatively tight stability and attitude control, or accommodating unique payloads.

The challenges outlined above require concerted efforts to create processes for realizing mega-constellations for science. A HeLEX class of Explorer missions (Recommendation 5-7) could offer opportunities for pathfinder concepts to develop manufacturing processes and capacity for multiple instrument builds that could support even larger constellation missions. A more general discussion of large scientific constellation mission requirements is given in Section 5.4.2.

the new Astrophysics Pioneers Program. Building on the earlier success, following these recommendations would allow for even more ambitious CubeSat missions.

NASA Heliophysics Strategic Technology Office

Recently, the Wallops Flight Facility, as part of Goddard Space Flight Center, implemented a new Heliophysics Strategic Technology Office (HESTO) to support NASA’s Heliophysics Division in all technology matters. HESTO’s tasks include recommendation of strategic investments, management of non-mission-specific technologies within the Heliophysics Division, coordination with other relevant technology groups, and fostering infusion of new technology into future missions.

The implementation of HESTO and its current work on gap and trend analysis and managing of H-TIDeS and HFOS is encouraging. However, the HESTO portfolio is currently limited and includes only a few elements, which are competitively selected through the NASA ROSES solicitation (ROSES B.8 [H-TIDeS] and ROSES B.10 [HFOS]). Current incubating technologies supported by NASA Heliophysics have historically outpaced the available opportunities for demonstration in flight. HESTO is already playing an important role to increase flight opportunities. For example, it works closely with the Sounding Rocket Program²⁸ and the Scientific Balloon Program²⁹ to manage flight technology maturation efforts, as well as with the Small Satellite and Special Projects Office that assists SMD with managing small satellite missions.

Conclusion: In addition to current suborbital technology maturation as part of full science investigations, the newly formed HESTO office can play a critical role in matching instrument development teams with technology maturation pathways, ultimately leading to flight demonstration. It would be important for these implementations to evolve into a strong advocate for PIs in negotiating access to space for technology maturation.

Recommendation 5-19: The National Aeronautics and Space Administration (NASA) Heliophysics Division should expand opportunities for instrument development that align with decadal survey goals and provide opportunities for in-flight demonstrations to raise technology readiness levels. NASA should consider expanding the role of the Heliophysics Strategic Technology Office to manage some of these activities and increase collaboration with the Space Technology Mission Directorate as appropriate.

5.4 PREPARATION FOR THE NEXT DECADE AND BEYOND

The decadal survey research strategy provides the framework for making significant progress in each of the focused research areas identified in Chapter 2. The guiding questions within each basic science and space weather theme are broader than these focus areas; continued progress requires a multidecadal effort. Priority areas of investment can be made in the next decade to prepare for future endeavors. These include investments in new technologies and advancing new mission architectures, establishing organizational structures within SMD to enable science that crosses discipline boundaries, and identifying future opportunities for international collaboration.

In May 2021, NASA, NSF, and NOAA sponsored the Heliophysics 2050 workshop to provide a forum for the community to discuss future goals. A second workshop on measurements and techniques was held in February 2022.³⁰ The vibrant discussions and strong community engagement at these workshops highlighted the importance of planning for the future. Planning for beyond the next decade is an ongoing effort and will require continued engagement by both the scientific community and agencies’ leadership.

___________________

²⁸ “Sounding Rockets,” NASA, https://www.nasa.gov/mission_pages/sounding-rockets/index.html, updated March 28, 2024.

²⁹ “Scientific Balloons,” NASA, https://www.nasa.gov/scientificballoons, updated January 10, 2024.

³⁰ “Heliophysics 2050 Workshop,” NASA Heliophysics Resources, NASA, https://science.nasa.gov/heliophysics/resources/heliophysics-2050-workshop, accessed June 2, 2024.

more than 20 percent of DSN antenna utilization hours during FY 2022 (NASA 2023a). Meanwhile, the DSN and NSN system capacity must also contend with planetary, astrophysics, Earth sciences, and international space missions.

System-wide telecommunications pressure comes at a time when many DSN and NSN assets are aging, new heliophysics sensors are generating rapidly increasing data rates, and the lunar exploration (Artemis) program is levying strict requirements for contiguous network coverage for safe crewed operations. A recent investigation of DSN congestion pointed out a significant loss of science coverage while assets were focused on the Artemis-1 mission primary spacecraft and associated rideshare SmallSats (Foust 2023).

NASA has proactively responded to this looming communication crisis on multiple fronts, including increasing the total number of 34 m DSN antennas, enhancing half of those antennas for high-capacity Ka-band operation, creating a new subnetwork of 17 m antennas solely for Lunar Exploration Ground Support, and exploring how commercial network partners can offload network demand. NASA SCaN actively pursues international partnerships to provide additional large apertures with increased geographic coverage. NASA is also exploring the role of infrared laser communications in increasing system capacity and has recently reported high-definition television-class data rates from a deep space lasercom system at a range of 16 million km (roughly 0.1 AU) (NASA 2023b).

The notional space science mission concepts created for this decadal survey included assessing the optimal use of the heterogeneous NASA network (DSN, NSN, and commercial partners). Table 5-10 lists the concepts that set the highest demands for the network in terms of data downlink rate, number of spacecraft, range to Earth, and orbit architecture.

During the Artemis-1 mission, the communication resources required by Exploration System Development Mission Directorate (ESDMD) missions have tended to get priority over SMD science missions. Recognizing that such conflicts have occurred before, the Space Operations Mission Directorate (SOMD), SMD, and ESDMD carried out the “DSN Futures Study,” which seeks to address near-term network issues (network scheduling efficiency, network and element brittleness, and fragility), and projected capability needs through 2050. Furthermore, NASA SCaN has discussed creation of a joint “prioritization working group” between the same invested parties to better prepare for and mediate mission conflicts. For this prioritization working group to fairly gauge all future missions, it is critical to evaluate the full set of U.S. government, international, and commercial communication obligations outside of NASA.

Conclusion: Increasing pressure on NASA’s shared communications infrastructure has the potential to create significant conflict, impacting future Heliophysics missions. A NASA-wide study is needed to find solutions before the situation becomes untenable.

5.4.4 Cross-Divisional and Cross-Directorate Coordination at NASA

Transformational research is often found at the boundaries between disciplines, and both cross-agency and cross-divisional collaboration have proven to be highly productive (Section 5.3). While cross-agency collaboration will remain important in future decades, this section focuses on cross-divisional coordination within NASA. Some of the most pressing and fundamental questions are shared across science divisions at NASA, and the unique expertise and skills of scientists from across SMD need to be harnessed to forge new frontiers. The solar and space physics community has developed a detailed expertise in understanding how a star interacts with its planets and is eager to share that knowledge in partnership with other divisions.

Cross-divisional research is discussed in Section 5.3.3, but collaboration needs to begin with the missions that provide data to enable scientific breakthroughs. There is a long history of collaboration between the Heliophysics and Planetary Sciences Divisions. The solar and space physics community has made major contributions to the scientific discoveries of interdisciplinary missions (see Section 2.3), starting from the Voyagers traversing the heliosphere (with groundbreaking observations in the magnetospheres of Jupiter, Saturn, Uranus, and Neptune along the way) to planetary missions such as MESSENGER at Mercury, MAVEN at Mars, Galileo and Juno at Jupiter, and the Cassini mission to Saturn. More recently, PSP made flybys of Venus, fueling the debate about the assumption that the magnetic field of Earth protects the planet from atmospheric escape (Figure 5-18).³¹

___________________

³¹ “Parker Solar Probe Captures Its First Images of Venus’ Surface in Visible Light, Confirmed,” NASA, https://www.nasa.gov/general/parker-solar-probe-captures-its-first-images-of-venus-surface-in-visible-light-confirmed, updated July 26, 2023.

Such opportunities enable quantitative comparisons of the solar wind interactions with the atmospheres of Earth, Venus, and Mars, critical for advancing understanding of planetary magnetospheres.

Opportunities exist for capitalizing on both the traditional mechanism whereby one division participates in another division’s mission (e.g., smaller missions that are achievable within a certain division’s budget but could be augmented to do more science by collaboration), and for truly cross-divisional missions (and funded by SMD) where scientists from each division are involved from the planning stages through the whole mission.

An example of a smaller mission is MAVEN where a Planetary Discovery mission included substantial Heliophysics objectives on the solar wind interaction with Mars’s atmosphere and ionosphere. For much earlier missions—Voyager, Galileo, Cassini, and MESSENGER—space physics goals were included in the original science objectives and highly capable (for the time) particles and fields instruments were competed and selected. In more recent years, as planetary missions have developed more specific and demanding science goals (requiring more payloads), the particles and fields instrumentation has become more limited (e.g., JUICE, Europa Clipper). Nevertheless, NASA and ESA are to be commended for setting up working groups to support interplanetary science on the cruise phases of JUICE and Europa Clipper as well as coordinating observations upstream and within the magnetosphere of Jupiter.

Looking to future missions, ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers) is a Mars mission funded by Heliophysics (originally selected in the Planetary SIMPLEx program) that is due to launch in 2024 to send two spacecraft to study solar wind energy and momentum through Mars’s unique hybrid magnetosphere. At Jupiter, the measurements of the intense radiation belts by Juno generated enthusiasm in Earth’s radiation belt community about a future mission to Jupiter that would send multiple spacecraft orbiting within the planet’s intense radiation belts to quantify particle acceleration, transport, and loss processes. Owing to the strength of Jupiter’s intrinsic magnetic field and the presence of Io, the radiation belt environment is extremely different from Earth’s. Yet some similar related phenomena have been observed, such as aurora, ultra-low-frequency and chorus waves, and solar wind–driven storms. Such a mission would be primarily for space physics but with some planetary applications and would be important for understanding particle acceleration processes.

The scientific overlap between Earth science and solar and space physics has garnered more interest in recent years. Changes in concentrations of anthropogenic greenhouse gases CO₂, and also CH₄ and H₂O, have caused warming in the troposphere, as well as cooling in Earth’s stratosphere and ITM system. For example, decreasing trends in thermospheric mass density of ~1 to ~10 percent per decade depending on altitude has been inferred from aerodynamic drag of LEO satellites. These decreasing trends in air mass density have significant implications on space debris accumulation. Owing to these significant and persistent anthropogenic trends, there is a need to understand ITM climate change and its impact in support of improved prediction and potential mitigation efforts. Particle precipitation can cause chemical changes in the mesosphere and lower thermosphere that can then propagate to lower altitudes and affect the concentration of ozone in the stratosphere. This is primarily observed in the polar winter and is a result of the polar vortex strength and other dynamics that are not fully understood. When and where the effect of energetic particle deposition is most significant is also not well known. This coupling between the magnetosphere and ionosphere–thermosphere system is of great interest to climate scientists, especially if it can explain some of the under-estimated chemical effects found in whole atmosphere model runs (e.g., Randall et al. 2005). Studies of these effects do not fit neatly into either Earth science or the solar and space physics funding opportunities, thus, it would be of great benefit to explicitly provide opportunities for cross-divisional research between ESD and HPD.

Some missions are truly cross-divisional and may require significant investment well beyond any single division’s budget. For example, the Habitable Worlds Observatory (with origins in the 2020 astronomy and astrophysics decadal survey [NASEM 2023]) has a broad scope of exploring habitability of exoplanets and would benefit from involvement of solar and space scientists (as well as planetary and Earth scientists). Similarly, a mission to interstellar space would be an ambitious multidecade mission to send a spacecraft out of the heliosphere to 1000 AU, deep in the very local interstellar medium (VLISM). This would be a truly cross-divisional mission with Heliophysics, Planetary and Astrophysics objectives that need to be addressed by an interdisciplinary team. Such a mission will take time to develop, including technologies such as “next generation” radioisotope thermoelectric generator power systems, enhanced communications, and, perhaps, onboard data processing.

___________________

³² This paragraph was updated after release of the report to reflect the status of solar sail propulsion technology.

community through confirmed missions like NASA’s IMAP mission (expected to be launched in 2025), ESA’s Vigil mission (to be launched around 2031), and Japan Aerospace Exploration Agency’s (JAXA’s) Solar-C mission (to be launched around 2028). The THEMIS mission is supported by a Canadian ground-based network of all-sky imagers. NASA supports launch sites at a variety of locales for both sounding rockets (e.g., Norway and Sweden) and balloons (e.g., New Zealand, Australia, Sweden, and Antarctica). NASA has cultivated partnerships with sister space agencies such as ESA and JAXA, observatories, and institutes. As discussed in Section 5.2.3, international collaborations are in progress in the area of space weather through SWFO and Space Weather Next programs.³³

Ongoing and expanding opportunities for international collaboration are key to the success of the decadal strategy outlined herein, to address the core science program and to support space weather science and operations. On the ground, there is increased need for measurements around the globe with heterogeneous instrument arrays—for example, the DASHI concept. In space, opportunities may be available for international participation in the upcoming program of record GDC and DYNAMIC missions as well as in the recommended notional LWS SPO and STP Links missions. In this context, it is noted that ESA’s Voyage 2050 Senior Committee Report specifically describes the scope for international cooperation in the areas of solar polar science and magnetospheric constellations (ESA 2021). Such cooperation would share costs and thus enable more rapid development of these missions. Planning future missions involving two or more space agencies may benefit from coordinated community effort such as that represented by the ENLoTIS international working group. The decadal survey committee notes that on July 22, 2024, this working group issued a report on the scientific case for a satellite mission to the lower thermosphere–ionosphere transition region, which represents the first steps toward potential ESA-NASA cooperation on developing such a mission (ESA/NASA 2024).

Last, an area of international collaboration that promises large science return on a modest monetary investment is to leverage the active international coordination between existing ground- and space-based instruments to jointly address scientific objectives. This can be achieved by, for example, coordinating multiobservatory campaigns, sharing consolidated data sets with the international community for scientific analysis, and by supporting the development of tools for coordinated data analysis. So far, these efforts have been largely voluntary with limited resources available at the institutional or agency level. The development of tools to enable coordinated observations, coordinated data analysis, and data sharing between international partners would facilitate such collaborations (see Recommendation 5-1).

___________________

³³ This paragraph was modified after release of the report to accurately reflect which country supports the network of all-sky imagers.