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  • Slide 1

THM-MMS coordination 1 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS THM-MMS coordination options: summary of Feb 25, 2014 kickoff Vassilis Angelopoulos, Tai Phan, David Sibeck, Sabine Frey, Cindy Russell Slide 2 THM-MMS coordination 2 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS 6 18 0 LT 12 LT 10 8 14 16 20 22 2 Circle at 12Re THM on Mar 7, 2014 RpxRa=1.145x11.455 Re, inc=8 o Line of apsides drift back: 51deg/yr MMS nominal launch for Mar 7, 2015 RpxRa=1.2x12 Re, inc=28 o Line of apsides drift back: 25.5deg/yr Nominal orbit configurations on XY GSE plane. How to address this large local time difference? X gse Y gse Magnetopause Bow shock Magnetotail on Mar 7, 2015 Apparent motion: ~1 o per day Slide 3 THM-MMS coordination 3 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #1. Enables Tail #2 (Phase2b) alignments, per plan, but MMS gets 2.5mo of commissioning Dayside #2 (Phase 1b, Sep. 2, 2016) Lines of apsides still ~45 o apart 12 MMS Launch: Mar. 7, 2015 THM@ ~16LT MMS@21LT 6 18 Tail#2 (Phase 2b, Mar. 11, 2017) Within 25 o ; THM apogees: 12-16Re; Get THM resonant orbits w/MMS ARTEMIS @ 55Re P1 P2 P3 P4 P5 MMS MMS on May 22 (2.5 mo. later, at Phase 1a start) Slide 4 THM-MMS coordination 4 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #2. Phase 0: prime observations, unique HSO science, cross-calibration; Phase 1a: good Dayside #0 (Phase 0, Jul. 4, 2015) Start MMS prime observations THM would be string of pearls Unique science, HSO-calibration 12 MMS Launch: Mar. 7, 2015 THM: ~15LT MMS: 16LT 6 18 Dayside #1 (Phase 1a, Jun. 12, 2016) Separation: 4.5-7.5 o (near-optimal) THM-MMS nested tetrahedra Slide 5 THM-MMS coordination 5 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #2 (continued): Optimal Phases 1b, 2b [Doubles proposed dayside conjunctions] Dayside #2 (Phase 1b, Jul. 10, 2017) Separation: 0-2 o (optimal) THM-MMS nested tetrahedra Tail#2 (Phase 2b, Jan. 16, 2018) Separation: 6-10 o (optimal) THM apg: 12-16Re. Resonant orbits P3 P4 P5 MMS ARTEMIS @ 55Re P1 P2 - Pros: Optimal HSO operation, double the amount of dayside conjunctions - Cons: 3.5 mo. commissioning, additional 4.5 mo. of mission duration Implications? Mitigations? (e.g., turn off instruments and/or spacecraft for 5-8 mo after Phase 0 and before Phase 1a to reduce cost/risk) Slide 6 THM-MMS coordination 6 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #3. Same as Option #2, but Phase 1a is now optimal (MMS adjusted perigee at 1000km). Dayside #0 (Phase 0, Jul. 5, 2015) Start MMS prime observations THM would be string of pearls Unique science, HSO-calibration near-optimal THM-MMS separation 12 MMS Launch: Mar. 7, 2015 at Ra 200km above nominal, then raise prg to 200km below nominal (1000km not 1200km) THM: ~15.2LT MMS: 16LT 6 18 Dayside #1 (Phase 1a, Jun. 14, 2016) Separation: 4-6 o (optimal) THM-MMS nested tetrahedra Slide 7 THM-MMS coordination 7 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #3 (continued): Same as Option #2 Dayside #2 (Phase 1b, Jul. 14, 2017) Separation: 0-2 o (optimal) THM-MMS nested tetrahedra Tail#2 (Phase 2b, Jan. 20, 2018) Separation: 6-10 o (optimal) THM apg: 12-16Re. Resonant orbits P3 P4 P5 MMS ARTEMIS @ 55Re P1 P2 - Pros: Same as Option 2 + near-optimal Phase 0 and optimal in Phase 1b - Cons: Same as Option 2. Implications? Mitigations? (Same as Option 2) Note: Mission duration can be reduced by 0.25 mo. (to 4.25mo. in addition to nominal) if the Phase 0 science is reduced by 0.25mo. Slide 8 THM-MMS coordination 8 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option pros, cons as function of launch time Cost/Risk Implications, Mitigations? Feb/MarApr/MayJun/JulAug/Sep Option #1Phase 2b conjunctions retained 2.5 mo. commissioning Phase 2b conjunctions retained THM-MMS coordination 12 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option 1 Fix RAP, Vary RAAN. 7d shadows: Green (req.


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