Final Test-Firing Set for Shuttle Rocket

The final full-scale test-firing of Morton Thiokol Inc.’s redesigned space shuttle booster rocket has been scheduled for Thursday, a company official said Monday.

The redesigned booster already has been successfully used on two shuttle launchings on Sept. 29 and Dec. 2.

Five of six scheduled test-firings were required before the 126-foot-long solid-fuel rocket could be launched, and the fifth was conducted on Aug. 18, according to company spokesman Rocky Raab. The test Thursday will be the sixth, he said.

The final test will determine how the rocket performs with propellant cooled to 40 degrees--established by engineers as the lowest operating temperature for the redesigned booster, Raab said.