The Nation - News from Dec. 10, 1986

Morton Thiokol Inc. test-fired a section of its space shuttle booster to measure the strain of launching conditions on a new rocket joint design, O-ring materials and insulation. The 2 1/2-minute test was the third of 10 planned, but it was the last to be conducted under conditions simulating those of Jan. 28, when the space shuttle Challenger exploded shortly after launching, officials of the Brigham City, Utah, company said. Allan J. McDonald, engineer-in-charge of booster redesign, said there was no indication of a gas leak, unlike the last two tests, which used the same or slightly modified designs of the Challenger booster joints.