Shuttle Columbia Fails Fourth Launch Attempt

It was Strike 4 for NASA’s oldest shuttle. A computer failed late in the countdown Saturday and grounded Columbia, already plagued by sluggish hydraulics, leaking fuel, even a hurricane.

The flight was not rescheduled. Launch director James Harrington expected a delay of at least a week.

NASA came within a half-hour of liftoff, but a computer needed to process vital commands for Columbia’s solid-fuel rocket boosters and fuel tank simply would not work.

“We did our best,” NASA test director John Guidi said, apologizing to the crew.

The seven astronauts looked glum as they crawled out of Columbia.

The failed computer - called a master events controller - is supposed to process commands for igniting the rocket boosters. It also controls separation of the spent boosters two minutes into the flight and the fuel tank six minutes after that.