NASA STS-117 FD11 Execute Package
FD10 MMT Crew Summary
The MMT met today to discuss mission progress including the latest status on the ISS Russian computer anomalies. The overall plan is to proceed toward undocking on FD 12 per the pre-mission 13 day timeline. The FD10 and FD11 SARJ checkouts, the FD10 MT translation, and the docked water dump planned on FD11 will provide the ISS team more confidence in the functionality of the Russian computers. As of the FD10 MMT, 4 of 6 lanes were continuing to function nominally with almost all the Russian systems active except for the Elektron. The Elektron is still off in order to consume Progress O2 prior to Progress undock. The ISS and Russian teams continue to work toward understanding the root cause of the Russian computer anomalies. The leading theories continue to be electromagnetic interference or a voltage/frequency problem with the normal secondary power feed.
Consumables Status: The MMT reviewed the latest consumables status and continues to be very pleased with the crew’s power conservation. The overall plan is to continue to utilize the modified Group C powerdown to allow for a 13+3 mission duration. The additional day would only be used as a docked day if the Russian computer situation degrades. It is expected that the ISS MMT, which meets around the start of the FD 11 off duty time will recommend undocking per this plan.
Additionally, the plan is still to maximize O2 transfer to ISS. On FD9 we transferred approximately 60 lbm of O2. The plan is to transfer as much as ~80 lbm of O2 after EVA-4. The final amount transferred is dependent on the ORCA transfer rate and transfer time available.
As you know all constraints have been lifted on use of the Shuttle WCS. The team is working towards a docked dump on FD11 using shuttle VRCS attitude control. After the dump, about an hour of attitude control on Russian thrusters is scheduled to serve as a good test of the handover to Russian thrusters that are required for undocking. Overall, the prop margins are very healthy and would support shuttle VRCS attitude control of the mated stack through the remaining docked period if required.
Recent Failures: The teams continue to investigate the high-pitched noise from the aft flight deck speakers when the ANNUNCIATOR BUS SELECT switch was taken to the MN B and MN C positions. The theory is that an oscillator inside the Annunciator Control Assemblies (ACAs) is somehow providing feedback through the speaker. It is unclear whether any action could be taken in flight to correct this problem.
There does not appear to be any issues with the small water leak in the Mineral/Sliver Biocide CWC port although the team will investigate whether there is any spare hardware onboard for the final CWC fills should the leak become worse.
