Prior POP planning horizon did not include larger crews
- Cost has not been assessed and implementation is not consistent with prior assumptions
Expedition crew plan depends significantly on:
- Rotation mechanism (Shuttle versus Soyuz)
- Crew Role and Task assignments
- How many of the 6/7 crew need backup crewmembers
OM suggests that 3 of the 6/7 crewmembers will be Russians rotated on Soyuz, remainder rotating on Shuttle
CB and MOD training have assessed role and task concept for larger crew and identified issues.
Goal of additional crewmembers is to increase utilization return
- Rotation options vary in benefit to utilization hours
Increment crewmembers will rotate in segments
- Logistics and increment requirement process need to be assessed
Recommendation: OM lead OC, OZ, CB, and MOD in defining minimum cost integrated crew rotation concept for larger crews.
Overview of Large Crew Scenario
3 Russians (or Russian sponsored crewmembers) rotate on Soyuz
- Do all Russian Segment core ops, including EVA
- Russian assignment to US or other IP core and utilization tasks subject to negotiation
- If no CRV, separate taxi crews twice a year for second Soyuz
3 or 4 Americans and Other IP rotate on Shuttle
- Do most US Core and all USOS EVA/Robotic
- Do most US and other IP Utilization
Soyuz and Shuttle rotatees are changed out asynchronously
- 6 month stays with a part of crew changed out more frequently
- Crews are less integrated - Structure forces some segmented ops
CDR Handover between Russian and US not straightforward
Each CDR will have 8-11 crewmembers over his or her increment
not counting Taxi crews
Most crewmembers serve under two different CDRs
Difficult to train all crewmembers together who will serve together
7-Person Crew Issues
Cannot rotate all 4 non-Soyuz rotatees on a single shuttle flight
- Shuttle recumbent seat limitation
- Need to rotate in groups of 2 or 3
Options
- Pairs: Rotate 2 crewmembers each of 4 shuttle flights/year
- Scientist: Rotate 3 crewmembers twice a year and the 4th member ("scientist") on each remaining shuttle flight
Without further guidance, MOD will assume:
6 crewmembers of the larger crews will get full systems training
- 3 are Russians rotating on Soyuz with an emphasis on Russian segment and support to Russian EVA
- 3 are US and non-Russian IPs will rotate as a group on shuttle with emphasis on US and non-Russian IP systems, including US EVA and Robotics
US and non Russian IP crew-members will receive training on US and non-Russian utilization
With CRV, 7th crewmember will be a dedicated utilization person who will rotate on shuttle flights not rotating the other 3 ("Scientist Option")
All crewmembers will have backups
Forward work
Assumptions needed to refine training cost and improve utilization:
- How many US/CSA/ESA/NASDA Core and Utilization tasks and hours should be assumed by the Soyuz-rotated crew?
- For 7-person crew, which rotation scheme maximizes utilization?
- Can we omit backups for some crewmembers?
- Does a resolution of the CDR issue bring any new training requirements?
Determine net utilization crew hour capability for 6/7 crew
Potential other Cost-bearing impacts:
- Crew logistics for larger crews and various rotation schemes
- Mission Integration complexity with frequent crew changeout
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