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Solar and Space Physics: A Science for a Technological Society
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SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
the same imaged region. The spacecraft would be in two coplanar orbits that pass through critical regions in
the magnetotail, flank, and subsolar magnetosphere. Each satellite would transmit radio waves to all others,
obtaining 190 line-of-sight densities, enabling tomographic images of plasma density over large regions
with an average spatial resolution of 0.32 R E at 12 s cadence. Each satellite would carry a suite of plasma
and field instruments that provide complementary in situ data throughout the imaged area for ground truth
as well as revealing the detailed plasma processes in the region. The nominal payload would include a
3-axis fluxgate magnetometer, electrostatic analyzers that measure three-dimensional ion and electron
distributions, a relaxation sounder to determine the ambient density, and a radio tomography instrument.
As for MagCon, the pre-CATE estimate for the MagCat mission was deemed beyond the scope of the
budget in the coming decade. Thus, there is a similar need in the coming decade to develop cost-effective
and efficient manufacturing procedures to mass produce a large number of spacecraft and instruments.
9.5.2.6 International Partnerships
International partnerships involving a consortium of individual space agencies can be an effective way
to pool limited resources to achieve an outstanding science goal whose importance is agreed upon by a
consensus of these agencies. For example, determining the cross-scale coupling physics involved in key
plasma processes is believed to be crucial for complete understanding of the causes and consequences
of these processes. None of the past, current (e.g., Cluster and THEMIS), or planned missions (e.g., MMS)
are designed to address the cross-scale aspects of these processes. However, a mission concept has been
developed in Japan, Canada, and Europe that involves a fleet of spacecraft performing simultaneous in situ
measurements at electron, ion, and fluid scales. Such a mission can investigate how turbulence transports
and dissipates energy over multiple scales and how kinetic microscale instabilities are modulated by macroscale properties of the plasma, as well as the relative role of global conditions versus microscale physics
in determining the structure and dynamics of magnetic reconnection. These are all important aspects of
SWMI critical science goals 6 and 7. This and other international, cross-agency partnerships should be
pursued when available and possible.
SWMI Imperative: Partner with other space agencies to implement consensus missions, such as a
multispacecraft mission to address cross-scale plasma physics.
9.5.3 DRIVE-Related Actions
In this section, the SWMI panel expands on a number of issues that have a material impact on the
national ability to conduct an effective and productive solar and space physics research effort.
9.5.3.1 Solar Wind Monitor
Knowledge of upstream solar wind conditions, the interplanetary magnetic field, and solar energetic
particles is required in essentially all of the programs that would address the SWMI science objectives.
Currently, instruments on the ACE 8 spacecraft, which orbits around the L1 libration point approximately
1.5 million km from Earth, provide these data. Follow-ons to ACE, which could also be instrumented with
a solar coronagraph to view Earth-bound coronal mass ejections, are needed both to satisfy SWMI science
goals and as part of a space weather forecasting system (see Chapter 7). The SWMI panel does not have
8 Information about the Advanced Composition Explorer (ACE) is available at http://www.srl.caltech.edu/ACE/.
Solar and Space Physics: A Science for a Technological Society
252
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
the same imaged region. The spacecraft would be in two coplanar orbits that pass through critical regions in
the magnetotail, flank, and subsolar magnetosphere. Each satellite would transmit radio waves to all others,
obtaining 190 line-of-sight densities, enabling tomographic images of plasma density over large regions
with an average spatial resolution of 0.32 R E at 12 s cadence. Each satellite would carry a suite of plasma
and field instruments that provide complementary in situ data throughout the imaged area for ground truth
as well as revealing the detailed plasma processes in the region. The nominal payload would include a
3-axis fluxgate magnetometer, electrostatic analyzers that measure three-dimensional ion and electron
distributions, a relaxation sounder to determine the ambient density, and a radio tomography instrument.
As for MagCon, the pre-CATE estimate for the MagCat mission was deemed beyond the scope of the
budget in the coming decade. Thus, there is a similar need in the coming decade to develop cost-effective
and efficient manufacturing procedures to mass produce a large number of spacecraft and instruments.
9.5.2.6 International Partnerships
International partnerships involving a consortium of individual space agencies can be an effective way
to pool limited resources to achieve an outstanding science goal whose importance is agreed upon by a
consensus of these agencies. For example, determining the cross-scale coupling physics involved in key
plasma processes is believed to be crucial for complete understanding of the causes and consequences
of these processes. None of the past, current (e.g., Cluster and THEMIS), or planned missions (e.g., MMS)
are designed to address the cross-scale aspects of these processes. However, a mission concept has been
developed in Japan, Canada, and Europe that involves a fleet of spacecraft performing simultaneous in situ
measurements at electron, ion, and fluid scales. Such a mission can investigate how turbulence transports
and dissipates energy over multiple scales and how kinetic microscale instabilities are modulated by macroscale properties of the plasma, as well as the relative role of global conditions versus microscale physics
in determining the structure and dynamics of magnetic reconnection. These are all important aspects of
SWMI critical science goals 6 and 7. This and other international, cross-agency partnerships should be
pursued when available and possible.
SWMI Imperative: Partner with other space agencies to implement consensus missions, such as a
multispacecraft mission to address cross-scale plasma physics.
9.5.3 DRIVE-Related Actions
In this section, the SWMI panel expands on a number of issues that have a material impact on the
national ability to conduct an effective and productive solar and space physics research effort.
9.5.3.1 Solar Wind Monitor
Knowledge of upstream solar wind conditions, the interplanetary magnetic field, and solar energetic
particles is required in essentially all of the programs that would address the SWMI science objectives.
Currently, instruments on the ACE 8 spacecraft, which orbits around the L1 libration point approximately
1.5 million km from Earth, provide these data. Follow-ons to ACE, which could also be instrumented with
a solar coronagraph to view Earth-bound coronal mass ejections, are needed both to satisfy SWMI science
goals and as part of a space weather forecasting system (see Chapter 7). The SWMI panel does not have
8 Information about the Advanced Composition Explorer (ACE) is available at http://www.srl.caltech.edu/ACE/.