Redesigned Shuttle Rocket Section Fired Second Time in Test of Joints

Morton Thiokol Inc. on Friday fired a section of a shuttle booster rocket to test two joints slightly different from the type blamed for the destruction of the space shuttle Challenger.

The 90-second test went off on schedule, with the rocket section spouting bright orange flame and billows of dense black smoke.

It was the second in a series of 10 planned tests through next July. Each of the tests involves slight but progressive modifications to the joint design.

Allan J. McDonald, engineer in charge of the booster redesign team, said the first three tests are to simulate conditions that existed on the ill-fated Challenger flight Jan. 28. The following seven are intended to “prove that all the problems have been solved” with the redesigned joint.

Officials said it would take at least two weeks to evaluate results of Friday’s test.

McDonald said the testing program was slightly behind schedule because of extensive scrutiny by federal officials.