A launch date for the penultimate flight of the 39-year-old space-shuttle program is under review again as technicians continue to make repairs on the shuttle Discovery's external fuel tank.
Discovery and its six-member crew were set for a Nov. 5 liftoff to the International Space Station. But a problem with plumbing on the liquid-hydrogen section of the tank prompted mission controllers to scrub the launch.
A subsequent inspection of the tank led to the discovery of cracks in two 21-foot-long vertical ribs, or "stringers," that reinforce the orange-hued shell near the top of the tank.
Since then technicians have discovered more cracked stringers and have been undertaking repairs on the orbiter, which was hauled off the pad and returned to the National Aeronautics and Space Administration's Vehicle Assembly Building to allow teams to inspect all the vertical supports.
So far, 32 stringers have been reinforced, according to a report in Florida Today. One issue that managers are trying to resolve is whether all 108 of the stringers should be strengthened.
As for launch opportunities, officials decided last Thursday that they wouldn't aim for a launch between Feb. 3 and 10, as they had initially planned. They didn't want to rush the repairs.
The next launch opportunity – shaped in part by unmanned resupply missions to the station, which are also scheduled for February – would be Feb. 27.
But it may be possible to move that up by a few days, a NASA spokesman told the Associated Press on Friday.
The shuttle is carrying a new cargo module to the station, which will remain as pressurized storage and work space once Discovery leaves. In addition, the shuttle is carrying up Robonaut 2, a joint project between NASA and General Motors to develop a humanoid robot with human-like dexterity. Ultimately, the robot's designers envision their astrobot taking over some of the more mundane tasks that space-station crew members must perform – including providing an uncomplaining third or fourth hand on tasks where both human hands are busy.
Although Discovery's mission is the next-to-last scheduled flight for the shuttle program, mission managers are planning a mission beyond the currently scheduled final flight. Congress included this in its budget authorization for fiscal year 2011, but so far, with the government running under a continuing resolution, the money for the mission hasn't been appropriated.