After months of delays caused by the appearance of cracks in space shuttle Discovery's external fuel tank, NASA officials announced the shuttle now has a planned launch date of Feb. 24. Space shuttle program managers briefed senior NASA officials Jan. 10 about the status of repairs and engineering evaluations associated with cracks found on 21-foot-long, U-shaped aluminum brackets called stringers on the shuttle's external fuel tank.
Managers approved installing small strips of metal, called radius blocks, on the tank's remaining stringers. "While additional testing and analysis continue, results so far show the modification will provide additional strength to the stringers," NASA officials said in a statement. Officials said technicians at NASA's Kennedy Space Center have begun modifications and repairs to space shuttle Discovery's stringers. Radius blocks are being added to 94 stringers, meaning the entire circumference of the external tank will be strengthened by the time all the repairs and modifications are finished.
At NASA's Johnson Space Center, STS-133 Mission Specialists Alvin Drew, Tim Kopra and Nicole Stott will conduct a review of spacewalking procedures. Commander Steve Lindsey and Pilot Eric Boe will fly to Kennedy in their T-38 training jets for approach and landing runs in Shuttle Training Aircraft at the Shuttle Landing Facility, according to the space agency.
When Discovery heads to the International Space Station on its final mission, it will be taking with it two key components-the Italian-built Permanent Multipurpose Module and Express Logistics Carrier 4-that will provide spare parts and storage capacity to the orbiting complex. Discovery also will deliver Robonaut 2, which will become the first humanoid robot in space.
Shuttle program manager John Shannon told reporters during a Jan. 11 news conference that a combination of inferior material and assembly issues was to blame for the cracks, but expressed confidence in the solution. "We're going to fly with a lot of confidence in this tank," the Associated Press reported him saying. "We've gotten rid of the uncertainty."
Adding a different, more somber layer of uncertainty to NASA's shuttle proceedings are the events surrounding last week's attempted assassination of U.S. Representative Gabrielle Giffords-her husband is space shuttle Endeavour commander Mark Kelly, scheduled to pilot the shuttle program's last mission in April. NASA officials declined to comment on the issue during the news conference.
"Out of respect to the family, we really are not ready to answer those questions today. We're going to let Mark decide really kind of what he needs to do," Bill Gerstenmaier, head of NASA space operations, said, according to an AP report. "Our hearts and prayers go out to the family, and we're really thinking about Mark in everything we do."
Discovery was NASA's third space shuttle orbiter to join the fleet at Kennedy Space Center and is currently the oldest orbiter in service. Early in its career, Discovery provided a base so astronauts could retrieve satellites, test new technologies and conduct two-week-long experiments in microgravity. NASA turned twice to Discovery for Return-to-Flight missions after accidents with shuttles Challenger and Columbia, and it launched the agency's landmark observatory, the Hubble Space Telescope.