MMS: Mission Implementation (II)

Orbit Design

The four MMS spacecraft will be placed into a low-inclination (28 degree) elliptical orbit with a perigee (geocentric) of 1.2 Earth radii and an apogee during Phase 1 of 12 Earth radii. (1 Earth radius = 6371 km.) As the orbit evolves during Phase 1, the spacecraft will sample reconnection sites at different locations on the dayside magnetopause. During Phase 2, the tail reconnection campaign, perigee will remain at 1.2 Earth radii, but apogee will be increased in stages to a final distance of 25 Earth radii.

The science operations phase of the mission begins after instrument commissioning is complete and will last two years, with data analysis continuing for another year after the end of the prime mission.

Spacecraft Formation