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Week of Mar 3:  Much work by AngelopolousAngelopoulos, Moore, Williams, and the THEMIS team on the initial options identified.  Telecon on March 6 for subgroup of folks working the options.  No telecon notes or agenda published; reviewed Angelopoulos initial cut at options, version 3.4.  Added Pete Spidaliere to the email list.

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  • Brent Robertson:  News on the MMS Launch Date?

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  • Trevor Williams and Vassilis Angelopolous Angelopoulos met to explore the options to identify actionable solution space for consideration.  Notes from Conrad:

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  • FOCUS FOR THIS TELECON --> Powerpoint for Discussion, and optimizer spreadsheet. Also,a PDF showing plots of MMS neutral sheet conjunctions for Phase0x.   Focus is on the optimization of "option 3" and to quickly provide information to settle the potential ULA cost issue.  Notes from the emails:  Vassilis Angelopolous Angelopoulos and his team have through further about what to do about retaining flexibility to overcome launch dispersions and avoid RAAN steering. Another approach can be to make the perigee raise on THEMIS late, after the MMS placement elements are known. Then by adjusting the time of raise we can optimize the steering of  THEMIS ahead or behind in RAP and make it meet MMS in orbit. However, this means THEMIS must keep drifting at a faster rate (which is acquired after last Fall’s perigee reduction maneuvers), which in turn could mean MMS would have to launch even later in LT, at 18LT.  This adds another month to the mission. The advantages are high flexibility in orbit for optimal matching, plus an extra month of dayside 0 (Phase0) prime MMS observations with the full 4 mo of commissioning.  Lowering MMS perigee through Phase1a-Phase1b would help a lot (the further down MMS goes the better the matching for less fuel from THEMIS and better joint observations during extended phase – right now THEMIS is spending all its got) but this further optimization is not required.  Comments are encouraged!  Write to Vassilis/Travor/Conrad directly or to the full email list as appropriate.

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  • Trevor Williams and Vassilis Angelopolous Angelopoulos will continue to explore the options to identify an actionable solution space for consideration
  • Brent Robertson will investigate the schedule by which this work would need to be completed in order for ULA to complete their necessary work before launch, and later will investigate what additional cost such a late change to the ULA work would incur. This is not trivial as it involves not only launch and launch vehicle considerations but also the full complement of range and communication assets that support a launch. 

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