Redesigned Shuttle Booster With Deliberate Flaw Successfully Tested

A redesigned booster for the space shuttle was test-fired with a deliberate flaw Thursday, and NASA engineers said the test appeared to show that the new rocket could withstand the leak that destroyed Challenger.

“This test would have prevented another Challenger,” said Jim Thomas, technical assistant to the manager of the solid rocket motor project at Marshall Space Flight Center, where the test was conducted.

In the test, hot exhaust gas was allowed to lick through deliberately flawed joint seals and reach the primary O-rings, a simulation of the kind of leak that blew up the shuttle Challenger and killed its seven crew members on Jan. 28, 1986.

Got Past O-Ring

On Challenger, the flaming gas got past the O-ring, which sealed a joint between segments of the rocket, and ignited the shuttle’s huge external liquid fuel tank.

Thursday’s test lasted about two minutes, the duration of the solid fuel booster rocket burn in an actual shuttle flight. Challenger exploded 73 seconds after its liftoff.

“We did not leak externally,” Thomas said after the test-firing. “My reaction would be that this is a cause for celebration.”

“We had a 100% successful test,” said John McCarty, director of the propulsion laboratory at Marshall, which is in charge of the shuttle’s propulsion systems. “We got the performance we expected.”

McCarty said the final assessment of the redesigned booster’s performance will not be made until the parts are disassembled. He said that could take several days.

More Successful Test

Engineers said the test was more successful than one conducted last November because so-called “side loads” did not work in the initial test.

In the test-firing, about 1 million pounds of weight is placed on the top of the three stacked booster segments, and on the sides mechanical arms apply pushing and pulling force, simulating the weight and flex experienced by the boosters during launch.

NASA plans another test in March and a final full-scale firing in Utah on April 6 prior to the scheduled August shuttle launch. Six other tests are planned after shuttle flights resume.