Test-Firing of Rocket Put Off by Malfunction

BRIGHAM CITY, Utah — A full-scale test-firing of a redesigned space shuttle booster was scrubbed Saturday in the countdown’s last second when the rocket’s ignition system failed, officials said.

A decision on rescheduling the test, considered a crucial milestone in the resumption of manned U.S. space flights, was to be made today, said Allan McDonald, Morton Thiokol Inc. vice president for shuttle engineering.

The earliest a new test could be conducted would be Monday afternoon, he said.

A “safe and arm” device in the rocket’s ignition system halted the countdown, McDonald said. Either the device, which is part of the booster, failed or the fire-control circuit feeding it information malfunctioned, he said.

Device Will Be Studied

McDonald said engineers would have to examine the device before determining the exact cause.

Earlier, the test-firing was delayed twice.

A computer caused a two-hour wait when it malfunctioned during the last in a series of dry-run countdowns, said John Thirkill, vice president for space operations at Morton Thiokol, which builds the booster.

A second delay occurred when a spot of frozen fuel was found inside a fitting in a system that rotates the nozzle at the base of the rocket during firing.

The 126-foot-long rocket was to be fired for two minutes in a horizontal position at Morton Thiokol’s test area, about 25 miles west of Brigham City. The first full-scale test of the redesigned rocket was conducted Aug. 30 and declared a success.