NASA and Roscosmos managers are understood to be negotiating the schedule of the upcoming Progress M-10M launch, due to a potential conflict with Endeavour’s STS-134 docked mission. Meanwhile, processing at Pad 39A is continuing to focus on the installation of the STS-134’s complex payload into Endeavour’s cargo bay.
Friday’s pad flow is being highlighted by the transfer of the STS-134 payload into Endeavour’s Payload Bay (PLB), following preparations in the Payload Checkout Room (PCR) which is located inside the Rotating Service Structure (RSS) at Pad 39A.
“The payload was delivered to the pad on Monday, and installed into the Payload Changeout Room on Tuesday. Opened up the PLBDs and completed optics; evaluation of optic measurements is underway. Will install the payload into the vehicle Friday,” summarized KSC Ground Operations on the latest Shuttle Standup/Integration report (L2).
The operation to transport the payload down the crawlerway to the pad and into the PCR all proceeded normally, allowing the RSS to extend back into the mate position on Thursday for the installation operation.
“OV-105/SRB BI-145/RSRM 113/ET-122 (Pad-A): S0600 Payload Operations: Preps for payload installation into the orbiter continue. After the RSS was extended the PCR main doors and orbiter payload bay doors were opened allowing access for orbiter and payload inspections,” noted the NASA Test Director (NTD) processing update (L2). “Payload installation is scheduled for Friday.”
While the STS-134 Launch Readiness Review (LRR) took place on Thursday at the Kennedy Space Center (KSC), the final wave of LOX tankers arrived at the pad, completing the replenishment of the storage tank.
Other scheduled pad flow tasks continuing to be completed on schedule, with only one additional – and minor – Interim Problem Report (IPR) being charged against the flow.
“Crew module PPO2 sensor calibration was completed. Preps for Helium Sig Test and Ball Seal Leak Checks picked up Thursday. Included in these preps will be LH2 and LO2 blank off plate installations,” added the NTD report.
“APU (Auxiliary Power Unit) will perform the 48-hr decay check per V1329 Friday. OMBUU (Orbiter Mid Body Umbilical Unit) mate is currently scheduled for Monday. S1287 Orbiter aft closeouts will begin Monday. Weekend Work: Post-installation payload operations on Saturday.
“New IPR-0032: During preps for vehicle power up a resistor bypass indicator for a ground power supply failed to indicate ON when commanded. The problem briefly delayed vehicle power up. The problem was traced to a fuse in the associated system. The system was reset and returned to nominal operation. Vehicle power up proceeded successfully.”
The latest report also confirmed IPR-26 – relating to the checks for any additional damage to the stack after an engineer accidentially dropped a wrench – is in the process of being closed, following a full check of the External Tank and Solid Rocket Boosters (SRBs) during the retraction of the RSS for payload operations.
“IPR 0026 update: SRB and ET engineers completed their additional, more detailed and closer proximity, walkdowns/inspections at Pad A, with the OWP (Orbiter Weather Protection) extended. No discrepancies were observed. No other hardware inspections are pending. IPR closure is in work.”
The incident occured during FRCS (Forward Reaction Control System) fuel post QD connection operations, when a 8” crescent wrench fell between a grating gap in the floor on the 207′ level and scruffed two tiles on Endeavour’s belly. It has since been confirmed the Thermal Protection System (TPS) will be able to fly “as-is” following slight repairs which have since been completed.
“A couple of items that were open at the time are now closed. A wrench drop out at the Pad – were able to show that the two damaged tiles only needed a slurry repair,” noted the Orbiter Project Office (OPO) at the Johnson Space Center (JSC). “The work has been done.”
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Progress M-10M Negotiations:
Options are being worked between NASA and Roscosmos managers on a possible conflict between Endeavour’s docked mission and the arrival of the Russian Progress M-10M ressuply vehicle.
As previously reported, Endeavour’s available launch window for the STS-134/ULF6 mission has been determined based on a complex ballet of schedules between Shuttle, Progress, Soyuz, and Solar Beta Angle cutouts.
Currently, the duration of Endeavour’s available launch window runs from April 19 – May 3. However, contained within that window is an April 23-29 cutout (or elimination of launch opportunities for Endeavour) due to the currently-scheduled rotation of Progress unmanned resupply vehicles at the International Space Station (ISS).
Endeavour currently remains on track for the opening launch target of April 19, while the Progress M-10M is set to launch on April 27 from the Baikonur Cosmodrome in Kazakhstan. The problem relates to a need for Endeavour to undock ahead of Progress M-10M’s arrival at the ISS, due to what is known as Dual Docked Operations (DDO) constraints.
It is understood the Russians may be willing to delay their Progress launch until May, should NASA managers opt against delaying Endeavour’s launch to April 29. However, that requires negotiations between the two agencies.
Other options include launching Progress M-10M on schedule, prior to loitering on orbit until Endeavour departs at the end of her docked mission, although this may be problematic due to the Russian vehicle’s time-sensitive cargo, understood to be a biological experiment which needs to be placed into one of the ISS’ freezers within days of launch.
Another option may allow for both vehicles to remain on their current schedules, with the Program Requirements Control Board (PRCB) discussing potential workarounds to STS-134 DDO constraints.
While it could be assumed STS-134 would hold priority on the docking schedule, negotiations between partner agencies are not allowed to make such assumptions. However, it is understood that at this time it is unlikely Endeavour’s launch date would be altered.
Also noted on Friday is a potential solution from the time-sensitive biological experiment standpoint, one which would see the payload being carried by Endeavour, releasing Progress from its need to dock with the ISS within a constrained timescale. Updates will follow pending additional information.
Also under discussion of late is the rendezvous altitude for Endeavour’s final trip to the orbital outpost, with considerations in place for the station’s phasing in relation to Soyuz.
“The rendezvous altitude on STS-134 is at 188 nautical miles (nm) for the first four opportunities,” noted Flight Operations & Integration. “After that, there is a scheduled burn to adjust for some Soyuz phasing, and then the rendezvous altitude will go to 191 nm.”
(Numerous articles will follow. L2 members refer to STS-134 coverage sections for internal coverage, presentations, images and and updates from engineers and managers. Images used: Larry Sullivan MaxQ Entertainment/NASASpaceflight.com. NASA.gov and L2 Presentations).