Columbia Launch Delayed Fifth Time

NASA postponed Columbia’s marathon research mission for a fifth time on Friday to inspect a potentially crack-prone rocket-engine component and to replace a balky computer.

The liftoff, which had been scheduled for today was reset for Sunday at 6:46 a.m. PDT. But the space agency didn’t rule out the possibility that the inspections and deteriorating weather could push their mission back into next week, and possibly even into mid-November.

Not since 1990 has a shuttle launch faced so many fits and starts. Columbia and its seven astronauts have been grounded since Sept. 28 by a succession of hardware problems and stormy weather.

The latest concern arose late this week just prior to a routine test firing of a shuttle rocket engine at NASA’s Stennis Space Center in Mississippi. Before the test got under way, engineers discovered a propellant leak in the test rocket’s high pressure oxidizer turbopump.