The Frustrations of Discovery

By J.D. Reed

When the gleaming white space orbiter Discovery moved onto the launch pad at the Kennedy Space Center in Florida early last month, it became both a soaring symbol and a thorny trial for NASA. On one hand, the 122-ft.-tall orbiter represented the agency's successful recovery from the tragic explosion 2 1/2 years ago of Challenger, the last manned U.S. space mission. Discovery was also a test: Could NASA, operating this time around with extraordinary caution and under intense scrutiny, pull off an A-O.K., on-time launch? That question has caused growing frustration in the space agency.

Just a fraction of a second before Discovery's three main engines were to ignite for a critical 20-second test firing last week, a computer detected a problem with a valve that regulates flow in cooling lines; the computer aborted the test. That was the fifth postponement of the engine test in the past two weeks. The latest delay may cause the agency to further set back its launch date, now scheduled for mid-September, by as much as a week. While John ; Talone, who manages work flow on the Discovery, believes a September date is still realistic, some agency officials have been saying privately that the accretion of glitches might push the launch into October. A few have deeper concerns. Says one NASA official: "There's a sense that we can't afford to have another accident, or it will mean the end of the shuttle program."

After last week's disappointment, Navy Captain Frederick Hauck, Discovery's commander, issued a carefully worded statement to the press: "Although we were disappointed that today's test did not go full term, we were impressed with the professional manner with which the launch team responded to the situation." While Talone believes that morale remains high, he admitted that "there is a certain amount of frustration because we thrive on doing these things completely and getting them done."

Two of the five aborted engine tests so far have been due to fueling problems, specifically in lines that carry liquid hydrogen from ground equipment to the tank. After two of the failures, several hours were required to unload more than half a million gallons of liquid hydrogen and oxygen from Discovery's tanks before technicians could examine problems. NASA engineers are not certain exactly what caused last week's problem. Said Joseph Lombardo, who oversees the shuttle's main-engine project at Marshall Space Flight Center in Alabama: "We don't know whether it was a faulty indication or really a malfunction in the valve." At week's end NASA officials suspected that a sensor had been affected by excessive engine cooling during the countdown. They planned to replace the valve and the sensor monitoring it. This week the agency was to schedule another test firing.

Whether or not the next test succeeds, other problems threaten to slow the countdown. Massive solid-fuel booster rockets like those on the shuttle must undergo a critical test, scheduled for Aug. 20 at the Morton Thiokol facility in Utah; the failure of a seal on a booster was responsible for the Challenger disaster. In addition, Discovery has a pressure-vent-line leak in one of its orbital maneuvering system engine pods, which came to light several weeks ago. NASA says repairs to the OMS pod, which involve cutting through a bulkhead, could delay the launch anywhere from a week to two months. NASA insists that the repairs and continuing caution during the countdown will be sufficient to fly the orbiter with confidence. Perhaps, but Discovery's trip into space may be farther off than anyone expected.

With reporting by Glenn Garelik/Washington