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

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

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)

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

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)

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

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.

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 <1mo. commissioning -- Option #2- Phase 0 prime obs. (1mo), unique HSO science, cross-cal. - Phase 1a near-optimal, Phases 1b, 2b optimal (doubles MMS-THM conjunctions rel. to Fall launch) - 3.5 mo. (0.5 less than nominal) of commissioning - 4.5 mo. extra in space compared to nominal launch @ 5LT - Phase 1a good, Phases 1b, 2b optimal (doubles MMS-THM conjunctions rel. to Fall launch) (no Phase 0 prime sci., but commissioning is now nominal) - MMS Launch at 12LT  MMS mission duration reduced by 2mo. relative to Feb/Mar launch, though [per Trevor] still 4.5 mo. extra compared to nominal launch @3LT (?) - Phase 1a good, Phases 1b, 2b optimal (doubles MMS-THM conjunctions rel. to Fall launch) (no Phase 0 prime sci., but commissioning is now nominal) - MMS Launch at 8LT  Total mission duration reduced by 4mo. relative to Feb/Mar launch, 3 mo. extra in space compared to nominal (@2LT)? - Phase 1a good, Phases 1b, 2b optimal (doubles MMS- THM conjunctions rel. to Fall launch) (no Phase 0 prime sci…) - MMS Launch at 4LT  Total mission duration reduced by 6mo. relative to Feb/Mar launch, 1 mo. extra in space compared to nominal (@2LT)? Option #3Same as above, but Phase 1a now has optimal MMS-THM conjunctions We probably want to discuss the lowest cost and risk strategies for any of these options, add and subtract implications (pros and cons) to this table and present jointly. In parallel we want to fine-tune the numbers in the tables to ensure they are in the ballpark.

9. THM-MMS coordination 9 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS The following 3 plots are an attempt to determine launch availability in the RAAN/AOP space. In that space, Right Ascension of Perigee, RAP=RAAN+AOP is a diagonal line. Because RAP drifts only slowly due to J2 terms and is related to the azimuthal variation of the line of apsides it is the quantity that determines alignment between the missions, to zero order. The first plot is the contour plots with: Option 1 (for Mar 11, launch solution at ~21LT corresponds to RAP~305 o ) Option 2 (for Mar 11, launch solution at ~16LT corresponds to RAP~230 o ) overlaid. The circles are my initial attempt to read the long term shadows, which was (after testing and also in retrospect having seen the revised long term shadows plot) incorrect. The second is the long term shadows plot with the above RAPs also overlaid. FOR THURSDAY 03/06/14 INTERIM DISCUSSION

10. THM-MMS coordination 10 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS These were the wrong choice because we interpreted the contours incorrectly. E.g., the white triangle seems to violate shadows but in the next page it is evident (flip back-and-forth) its outside the red area Option 1, 21LT RAP=305 (Fall-like) Options 2,3 16LT RAP=230 (Spring like)

11. THM-MMS coordination 11 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option 1, 21LT RAP=305 (Fall-like) Options 2,3 16LT RAP=230 (Spring like) Five new potential solutions are shown here. We are now checking with orbit integration if any pass all constraints. Nominal window, from previous page

12. 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.<1hr); 14d shadows: Blue (req.<2hrs); LongShadows: Red (req.<3hr) NS Conjunctions: Black (req. >100min)