NASA delays space shuttle launch a fourth time
NASA has delayed the launch of space shuttle Discovery for a fourth time amid valve concerns. After meeting all Friday at Kennedy Space Center in Florida, shuttle managers decided against launching in a week. The launch had been targeted for no sooner than Feb. 27; it was not immediately known late Friday when it might be rescheduled.
NASA originally hoped to send Discovery to the international space station on February 12th. But extra tests were ordered for the valves that control the flow of hydrogen gas into the external fuel tank during liftoff. One of those valves broke during the last shuttle launch in November.
Managers want to make sure if that happens again, the ship and its seven-man crew will be safe.