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 and how to move forward Vassilis Angelopoulos, Sabine Frey, Cindy Russell, Tai Phan, David Sibeck

2. THM-MMS coordination 2 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS MMS nominal launch for Mar 7, 2015 (RpxRa=1.2x12 Re, inc=28 o ): Line of apsides drifts back: 25.5deg/yr (counter clockwise) 6 18 0 LT 12 LT 10 8 14 16 20 22 2 Circle at 12Re 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 orbit motion: clockwise ~1 o per day Apparent motion: ~1 o per day THM on Mar 7, 2014 (RpxRa=1.145x11.455 Re, inc=8 o ) Line of apsides drifts back: 51deg/yr (counter clockwise)

3. THM-MMS coordination 3 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Nominal (Spring-like) MMS launch for Mar 7 th is shown in the white area here (but for Mar 11 th, adapted from MMS_WinterBlock_MIWG_CS.pptx) Option 1, 21LT RAP=300 (Fall-like) Options 2,3 16LT RAP=225 (Spring like) Nominal (Spring-like) 3-5LT launch resides here (RAP=36-60) Note: Phase 0 is 5-6mo. Shadows ~3.5hrs (max in Phase 0)

4. THM-MMS coordination 4 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, Aug. 28, 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. 4, 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)

5. THM-MMS coordination 5 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: Ciel (req.<2hrs); LongShadows: Red (req.<3hr) NS Conjunctions: Purple (req. >100min) Available window: RAAN=[55 o,65 o ], 10 o wide, allows for a 40min launch window. (Mar 07 is similar) Investigation of other APERs will be important (under study) to determine a feasible launch plan. Compliant RAANs: ~ 51 o … 65 o

6. THM-MMS coordination 6 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option 1 Vary AOP, RAAN (Explore in 2D). LongShadows: Left; NS Conjunctions: Middle; LongShadows+Conjunctions: Right Phase2b shadows RAP= 300 Phase0,1 shadows Optimal region Optimal region (from 1D) ( ) Optimal region ( ) Optimal region ( ) Shadows and Conjunctions

7. THM-MMS coordination 7 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #1 (continued). Assessment and future work -Solution space: identified a 10 o -wide RAAN interval with no violations -Pros: Enables Phase 2b alignments -Cons: Reduced commissioning to 2.5 mo. commissioning Future work -Confirmation/validation of available solution space (FDOA). -Risk implications/mitigations of 2.5 mo. commissioning (project). -Improvements on solution space (expand solution window if necessary)? -Use APER-RAAN diagrams to arrive at a launch vehicle request (on-going)

8. THM-MMS coordination 8 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, Jun. 29, 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. 7, 2016) Separation: 4.5-7.5 o (near-optimal) THM-MMS nested tetrahedra

9. THM-MMS coordination 9 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. 5, 2017) Separation: 0-2 o (optimal) THM-MMS nested tetrahedra Tail#2 (Phase 2b, Jan. 10, 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)

10. THM-MMS coordination 10 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, Jun. 30, 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. 10, 2016) Separation: 4-6 o (optimal) THM-MMS nested tetrahedra

11. THM-MMS coordination 11 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Option #3 (continued): Same as Option #2 Dayside #2 (Phase 1b, Jul. 10, 2017) Separation: 0-2 o (optimal) THM-MMS nested tetrahedra Tail#2 (Phase 2b, Jan. 15, 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.

12. THM-MMS coordination 12 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Options 2/3: Fix RAP, Vary RAAN. 7d shadow: Green (req.<1hr) 14d shadow: Ciel (req.<2hrs); LongShadows: Red (req.<3hr?) NS Conjunctions: Purple (req. >100min) Available window: RAAN=[45 o,55 o ], 10 o wide, allows for a 40min launch window. (This is for Option#2 but solution for Option #3 is very similar). “Nominal” (3-5LT) Spring-like launch 1 st year max shadows Compliant RAANs: ~ 42 o … 55 o

13. THM-MMS coordination 13 Summary of options from Feb 25, 2014 telecon ARTEMIS THEMIS ARTEMIS THEMIS Options #2&#3 (continued). Assessment and future work -Solution space: identified a 10 o wide RAAN interval with similar long term shadows as nominal Spring-like launch and no early shadows/NS conjunction violations -Pros: -Additional Phase 0 prime MMS observations (0.5-1.5mo.) with unique HSO component (THM nearby, string of pearls) and cross-calibration. -Near-optimal or entirely optimal THM-MMS conjunctions in Phase 1a is in addition to the entirely optimal conjunctions in Phase 1b. More than doubles dayside conjunctions relative to original proposal for Fall launch. -Optimal THM-MMS conjunctions Phase 2b -Cons: -Reduced commissioning to 3.5 mo. commissioning (3-4mo) in exchange for 1month of extra prime observations in Phase 0. -Extra time in space (4.5mo. in addition to nominal Spring-like launch at 5LT). Future work -Completion of Option #3 solution space. -Confirmation/validation of available solution space (FDOA). -Risk mitigation of 3.5 mo. commissioning (partial loss of 1mo. Phase0 science?) -Risk and cost implications of 4.5 mo. extra mission duration relative to nominal? -Improvements on solution space (expand solution window if necessary)? -Use APER-RAAN diagrams to arrive at a launch vehicle request (on-going)

14. THM-MMS coordination 14 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.