Systematic Identification of Preferred Orbits for Magnetospheric Missions: 2. The “Profile” Constellation

Abstract

Using orbital criteria developed in Part 1 of this study (Stern, [1]), a “Profile” constellation mission is developed for studying the Earth’s magnetosphere. The basic “Profile” has six satellites in each of two close orbits with apogee 25R_E or 20R_E, (Earth radii, 1 R_E = 6371 km), but it can be extended to a “Twin Profile” mission with two coplanar constellations (total of twenty-four spacecraft), covering the magnetosphere end-to-end and requiring only one launch. One constellation of twelve then has apogee at midnight (or at other times, dusk), the other at noon (or dawn), and the two exchange positions every six months. The small satellites (17 kg, 29 w) will measure magnetic fields, ion and electron energy spectra, and plasma bulk flows. They require a minimal Δv and can therefore be flung off in pairs from a spinning mother ship, assuring a scientifically desirable spin axis and other benefits. Simulation codes derive the week-by-week coverage of ten magnetospheric regions by the twelve satellites, as well as the annual number of hours certain formations occur, e.g. ten+ satellites within 2R_E of the tail’s neutral sheet. Of particular interest is the tight clustering of six to twelve satellites at r > 23R_E (for 25R_E apogee), enhancing (at various times) local coverage of the substorm reconnection region, low latitude boundary layer and bow shock. The article concludes with a list of thirty targeted scientific investigations, each with its appropriate formation.