Discovery’s final mission to the International Space Station (ISS) remains on track for February 24, despite a late change to the crew. With Mission Specialist – and lead spacewalker – Tim Kopra injured in a biking accident, managers have decided to assign Steve Bowen as part of the crew as his replacement, with Kopra’s MS2 duties redistributed among the crew.
Discovery will once again be awoken from her slumber on Wednesday for a number of pre-rollout configuration checks. Currently, the STS-133 stack is scheduled to roll back out to Pad 39A on February 1 – pending the completion of modification work on the stringers located on the LO2/Intertank region of External Tank (ET-137).
Known as Space Shuttle Vehicle (SSV) power up, engineers will also take the opportunity to adjust the pressure on one of her Auxiliary Power Unit (APU) gearboxes.
Modifications to over 100 stringers on ET-137 are proceeding to schedule, with technicians now working on Panel 8’s family of stringers, while stringers on Panel 3 have already been modified with their radius block installations and have since been covered with the BX-265 foam.
“ET-137 Stringer Full Modification Update: +Y Panel 3: Foam spray application and acceptable pull testing on stringers 6-18 is complete. Foam trimming operations are in work,” noted the NASA Test Director (NTD) update on the status of modification work (L2).
“+Y Panel 7: Radius block installation is complete on stringers 10, 13, 15, & 17. Fastener removal was worked on stringers 12, 14, 16, & 18; match drilling is in progress. -Y Panel 2: Radius block installation is complete on stringers 12, 14, 16, & 18.
“Radius block installations continue on S-1 & S-5. Borescope is complete, prepping for primer. Fastener removal is complete on stringers 11, 13, 15 and 17. A nonconformance (NCD) was picked up on some oversize holes and is being addressed. Ready for foam spray is expected early Thursday.”
Although a spray gun problem was encountered during work on the tank early this week, but this hasn’t stopped progress being made on all four ‘sides’ of the tank.
“-Y Panel 6: S-11 radius block installation was in work last night; however 2 fasteners will not be available for installation until sometime today (Wednesday). Fastener removal, match drilling, borescope, and primer are complete on stringers 2, 4 and 8. Fastener removal is in progress on stringers 12, 14, 16 and 18,” added the NTD report.
“+Z Panel 1: Completed primer application. It is in cure. -Z Panel 8: Cleaning and preparation for primer application is in work.”
S11-7 is a classed as a suspect material stringer with the “mottled” appearance, which is without a doubler, but has a radius block installed.
This was the second test of a suspect material stringer with a radius block modification. When compared to the first test, stringer S17-7 – which was pulled on Friday night – the results were very comparable, again providing good date for the upcoming flight rationale meeting at the Delta Flight Readiness Reviews (FRRs).
STS-133 Specific Articles (click for numerous background content on the ET and relating to this article): http://www.nasaspaceflight.com/tag/sts-133/
Following the unfortunate injury to STS-133 Mission Specialist Tim Kopra, NASA managers have decided he will not be able to recover in time to take up his role on Discovery’s upcoming mission, based on the current launch date.
“As a result of his accident this last weekend, Tim Kopra will be unable support the scheduled launch of STS-133. Steve Bowen will be assigned to fly in his place,” noted confirmation from the Astronaut Office (L2).
According to his bio, Bowen was selected by NASA in July 2000 as a mission specialist. He reported for training at the Johnson Space Center in August 2000. Following the completion of two years of training and evaluation, he was initially assigned technical duties in the Astronaut Office Station Operations Branch.
A veteran of two spaceflights, STS-126 in 2008 and STS-132 in 2010, Bowen has logged a total of 27 days, 14 hours, 57 minutes and 39 seconds in space, including 34 hours and 30 minutes of EVA in 5 space walks.
“Steve’s previous EVA experience will allow him to quickly come up to speed for the mission, and MS2 duties will be redistributed among the crew,” added the Astronaut Office update, adding confirmation the launch date will remain on track for February 24.
“This will allow for all mission objectives to be accomplished as originally planned in the current February 24th launch window. If for some unanticipated reason STS-133 slips significantly, it is possible that Tim could rejoin the crew.”
(Further updates and articles will follow. Refer to live coverage threads linked above. L2 members refer to STS-133 live coverage sections for internal coverage, presentations, images and and updates from engineers and managers. Images used, NASA.gov and via L2 acquired PRCB presentations).