Copyright © National Academy of Sciences. All rights reserved.
Solar and Space Physics: A Science for a Technological Society
REPORT OF THE PANEL ON SOLAR WIND-MAGNETOSPHERE INTERACTIONS
251
and multisatellite constellation missions to obtain measurements of the physical parameters necessary to
accomplish these science objectives. A MEDICI-like mission will address these objectives through global
imaging, which is technically feasible primarily for the inner and middle magnetosphere. For the outer
magnetosphere, which forms the primary solar-wind entry and energy-storage region, the highly tenuous plasma makes “imaging” by means of local measurements on many spatially separated satellites the
best approach to resolving global and mesoscale structure. Below, some exciting mission concepts are
highlighted that can address these challenging objectives but will require technology developments in the
coming decade to achieve feasible cost and readiness levels.
Magnetospheric Constellation Mission (MagCon)
Science Goals. Understanding the mass and energy transport at global and mesoscales in Earth’s magnetospheric plasma sheet and reconnection regions of the near-Earth magnetotail, plus the dayside and flanks
of the magnetopause and bow shock regions, can be implemented using a multisatellite in situ mission
such as the MagCon mission. The prime overarching objective of the mission is to determine how the magnetosphere stores, processes, and releases energy in the magnetotail and accelerates particles that supply
the inner magnetosphere’s radiation belts. It would track the spatial-temporal plasma structures and flows
associated with the solar wind plasma entry across the magnetopause and transport within and through
the magnetotail. On the dayside and flanks the constellation would provide multipoint measurements of
the upstream solar wind input, and the response throughout the magnetosphere, enabling determination of
how the entire system responds to variable solar wind driving. In the magnetotail it would provide a map
of the global plasma flows and field configurations, leading to determination of whether they are internally
developed or externally triggered. Throughout the mission, MagCon would provide a global “picture” of
these otherwise invisible regions of the magnetosphere.
Mission Concept. MagCon uses many satellites separated by mesoscale distances (~1-2 R E ) that make
magnetic field plus plasma and energetic particle distribution function measurements at multiple points
simultaneously with relatively rapid cadence. The mission requires a significant number of spacecraft, 36 in
the concept the SWMI panel evaluated, to achieve mesoscale spacing while filling a significant fraction of
the near-Earth space using orbits with perigees in the 7-8 R E range and apogees dispersed uniformly up to 25
R E with low inclination. The satellites would be simple ~30-kg-class spin-stabilized vehicles with their spin
axes perpendicular to the ecliptic. Each spacecraft would carry a boom-mounted fluxgate magnetometer,
a three-dimensional ion-electron plasma analyzer, and simple energetic ion-electron particle telescopes.
To implement such a constellation requires development of small satellite systems and instruments
that can be more cheaply manufactured and tested in a reasonable time frame (2-3 years) with acceptable
reliability levels, plus a better match between launch vehicle capabilities and constellation mission needs.
Magnetospheric Constellation and Tomography (MagCat)
Science Goals. With science objectives similar in many respects to those of MagCon, MagCat would
address some of the most critical processes in Sun-Earth connections: plasma entry into the magnetosphere,
plasma-sheet formation and dynamics, and investigation of bow-shock structure, plasmaspheric plumes,
and other mesoscale structures that form in response to solar-wind variability. To achieve this objective
requires observations with a minimum spatial resolution of 0.5 R E at a minimum time cadence of 15 s.
MagCat could provide those required measurements.
Mission Concept. MagCat is a 20-spacecraft mission that would provide a combination of two-dimensional
images of the equatorial outer magnetosphere and multipoint in situ observations made concurrently and in
Solar and Space Physics: A Science for a Technological Society
REPORT OF THE PANEL ON SOLAR WIND-MAGNETOSPHERE INTERACTIONS
251
and multisatellite constellation missions to obtain measurements of the physical parameters necessary to
accomplish these science objectives. A MEDICI-like mission will address these objectives through global
imaging, which is technically feasible primarily for the inner and middle magnetosphere. For the outer
magnetosphere, which forms the primary solar-wind entry and energy-storage region, the highly tenuous plasma makes “imaging” by means of local measurements on many spatially separated satellites the
best approach to resolving global and mesoscale structure. Below, some exciting mission concepts are
highlighted that can address these challenging objectives but will require technology developments in the
coming decade to achieve feasible cost and readiness levels.
Magnetospheric Constellation Mission (MagCon)
Science Goals. Understanding the mass and energy transport at global and mesoscales in Earth’s magnetospheric plasma sheet and reconnection regions of the near-Earth magnetotail, plus the dayside and flanks
of the magnetopause and bow shock regions, can be implemented using a multisatellite in situ mission
such as the MagCon mission. The prime overarching objective of the mission is to determine how the magnetosphere stores, processes, and releases energy in the magnetotail and accelerates particles that supply
the inner magnetosphere’s radiation belts. It would track the spatial-temporal plasma structures and flows
associated with the solar wind plasma entry across the magnetopause and transport within and through
the magnetotail. On the dayside and flanks the constellation would provide multipoint measurements of
the upstream solar wind input, and the response throughout the magnetosphere, enabling determination of
how the entire system responds to variable solar wind driving. In the magnetotail it would provide a map
of the global plasma flows and field configurations, leading to determination of whether they are internally
developed or externally triggered. Throughout the mission, MagCon would provide a global “picture” of
these otherwise invisible regions of the magnetosphere.
Mission Concept. MagCon uses many satellites separated by mesoscale distances (~1-2 R E ) that make
magnetic field plus plasma and energetic particle distribution function measurements at multiple points
simultaneously with relatively rapid cadence. The mission requires a significant number of spacecraft, 36 in
the concept the SWMI panel evaluated, to achieve mesoscale spacing while filling a significant fraction of
the near-Earth space using orbits with perigees in the 7-8 R E range and apogees dispersed uniformly up to 25
R E with low inclination. The satellites would be simple ~30-kg-class spin-stabilized vehicles with their spin
axes perpendicular to the ecliptic. Each spacecraft would carry a boom-mounted fluxgate magnetometer,
a three-dimensional ion-electron plasma analyzer, and simple energetic ion-electron particle telescopes.
To implement such a constellation requires development of small satellite systems and instruments
that can be more cheaply manufactured and tested in a reasonable time frame (2-3 years) with acceptable
reliability levels, plus a better match between launch vehicle capabilities and constellation mission needs.
Magnetospheric Constellation and Tomography (MagCat)
Science Goals. With science objectives similar in many respects to those of MagCon, MagCat would
address some of the most critical processes in Sun-Earth connections: plasma entry into the magnetosphere,
plasma-sheet formation and dynamics, and investigation of bow-shock structure, plasmaspheric plumes,
and other mesoscale structures that form in response to solar-wind variability. To achieve this objective
requires observations with a minimum spatial resolution of 0.5 R E at a minimum time cadence of 15 s.
MagCat could provide those required measurements.
Mission Concept. MagCat is a 20-spacecraft mission that would provide a combination of two-dimensional
images of the equatorial outer magnetosphere and multipoint in situ observations made concurrently and in