aurora
The Mission

Orbits

The five THEMIS spacecraft (probes) were placed in highly elliptical orbits where the spacecraft line up at apogee every four days. The apogee rotates slowly around the Earth to cover the dayside, dawnside, nightside, and duskside of the magnetosphere. Initially, right after launch in 2007, the 5 THEMIS spacecraft were lined up in the same orbit. Since 2011, P1 and P2 have become ARTEMIS and orbit the moon, while the 3 remaining Earth-orbiting probes are able to synergize observations with other heliophysics missions such as Van Allen Probes (VAP) and Magnetospheric Multiscale (MMS).


Stage 42:  Dayside Science Phase, HSO Optimization with MMS and VAP
01/02/19 - 03/30/19

In the dayside science phase the apogee of P3, P4, and P5 are approximately 12 Re. The probes are separated by 1000 km to a few Earth radii at apogee. MMS is at opposition in the tail. THM-MMS on resonant orbits, to study dayside-nightside reconnection simultaneously.

Stage 41:  Dayside Science Phase, HSO Optimization with MMS and VAP
08/29/18 - 01/01/19

In the dayside science phase the apogee of P3, P4, and P5 are approximately 12 Re. The probes are separated by 1000 km to a few Earth radii at apogee. MMS is at opposition in the tail. THM-MMS on resonant orbits, to study dayside-nightside reconnection simultaneously.

Stage 40:  Dusk Science Phase, HSO Optimization with MMS and VAP
05/20/18 - 8/28/18

In the dusk science phase the apogee of P3, P4, and P5 are approximately 12 Re. The probes are separated by 1000 km to a few Earth radii at apogee. MMS is at opposition in the dawn sector, and VAP is in the tail sector. THM is on MMS-resonant orbits, exploring asymmetries of reconnection and drivers of magnetopause boundary layer flows.

Stage 39:  Tail Science Phase, HSO Optimization with MMS and VAP
02/13/18 - 5/19/18

In the tail science phase the apogee of P3, P4, and P5 are approximately 12 Re. The probes are separated by 1000 km to a few Earth radii at apogee. THM on sidereal period resonances, together with GBOs studies reconnection fronts, injections, links to VAP in the dawn sector; MMS studies drivers at opposition in the dayside.

Stage 38:  Dawn Science Phase, HSO Optimization with MMS and VAP
07/23/17 - 2/12/18

In the dawn science phase the apogee of P3, P4, and P5 are approximately 12 Re. The probes are separated by 1000 km to a few Earth radii at apogee. MMS is at opposition in the dusk sector, and VAP is in the dayside sector. THM is on MMS-resonant orbits, exploring asymmetries of reconnection and drivers of magnetopause boundary layer flows.


Click here to see past orbital configurations.