STS-133 Now Scheduled for February 24

STS-133 Now Scheduled for February 24

At a press conference this afternoon, NASA officials announced that the new launch date for STS-133 (Discovery) is February 24. They also said that the launch date for STS-134 (Endeavour) may slip to April 18, and they are “chatting” about a late August date for the final shuttle mission, STS-135.

The Discovery launch has been delayed since November 5 first because of a gas leak, and then because of cracks that were discovered in “stringers” on the External Tank (ET). Space shuttle program manager John Shannon described in great detail the detective work shuttle engineers undertook to determine the root cause of the stringer problems — low fracture toughness combined with assembly stresses. They are installing “radial blocks” on the stringers and are confident that it will resolve the issue. He later added that they expect that the ET for the STS-135 mission will have the same problems and require the same fix, but the tank for STS-134 is from an earlier lot and likely is not affected. NASA plans to do a tanking test for STS-134 and then x-ray the side of the ET that is accessible on the launch pad to confirm that it is OK. That would slip the launch date for STS-134 from April 1 to April 18.

STS-134 at one time was expected to be the final shuttle mission, but Congress included language in the 2010 NASA authorization act directing NASA to fly one more flight — the “launch on need” mission. Outside the agency, that mission has been called STS-135 for many months, but internally, NASA has been referring to it as STS-335 because it was a contingency mission. NASA Associate Administrator for Space Flight Bill Gerstenmaier said at the press conference that NASA now considers that a “real” mission and will refer to it as STS-135 internally, too. NASA is “mentally shifting gears,” he said. He responded to a question about how long the shuttle program can continue budgetarily by pointing out that currently the agency has enough funds though April, which would cover STS-133 and STS-134. The agency will have to wait to see how much funding Congress provides after the current Continuing Resolution expires on March 4. June 28 is the nominal launch date for STS-135, but International Space Station (ISS) Program Manager Mike Sufferdini said that he would like to fly late in the fiscal year to allow as many Orbital Replacement Units (ORUs) — spare parts — to be ready for launch as possible. He said they had been “chatting” about a late August launch date as a possibility.

Meanwhile the February 24 launch date for STS-133 required considerable flexibility on the part of the other ISS partners. The Japan Aerospace Exploration Agency (JAXA) is getting ready to launch its HTV cargo spacecraft to the ISS and in order for everything to work out, had to agree to extend its on-orbit stay time to 60 days. The European Space Agency (ESA) also is getting ready to launch one of its cargo spacecraft, the ATV, and the Russians are planning a spacewalk for about the same time as the shuttle would arrive at the ISS. The partners worked together to make the February 24 launch date work, according to Mr. Sufferdini.

Mr. Gerstenmaier stated at the outset that they would not address questions today about the status of STS-134, which will be commanded by Mark Kelly. Captain Kelly is the husband of Rep. Gabrielle Giffords who is in critical condition after being shot in the head in Tuscon, AZ on Saturday during a public meeting with her constituents. Mr. Gerstenmaier said that “out of respect” today was not the time to discuss the matter and “our hearts and prayers go out to the family and we’re really thinking about Mark in everything we do.”

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