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.

Stage 37:  Dayside Science Phase, HSO Optimization with MMS and VAP
04/20/17 - 7/22/17

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 with MMS at opposition in the tail. THM and MMS study dayside and nightside reconnection simultaneously; VAP determines geoeffectiveness in the dusk sector.

Stage 36:  Dusk Science Phase, HSO Optimization with MMS and VAP
01/13/16 - 4/19/17

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 in ascend phase (1x). L-shell crossings determine particle sources and wave contribution to inner magntosphere particle flux growth/decay. VAP is in the dusk sector.

Stage 35:  Tail Science Phase, HSO Optimization with MMS and VAP
10/28/16 - 1/12/17

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, to detect reconnection fronts, electron injections, and links to VAP waves in the dusk sector. MMS is at opposition in the dayside, and VAP is in the dusk sector.

Stage 34:  Dawn Science Phase, HSO Optimization with MMS and VAP
07/30/16 - 10/27/16

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 tail sector. Coordinated L-shell crossings determine particle sources and wave contribution to inner magnetosphere particle flux growth/decay.

Stage 33:  Dayside Science Phase, HSO Optimization with MMS and VAP
04/09/16 - 07/29/16

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 at the plasma sheet boundary studying flux transport, and connects to VAP in the dawn sector.


Click here to see past orbital configurations.