NASA Grounds Space Shuttles; Woes Pile Up

National Aeronautics and Space Administration officials Friday grounded the space shuttle fleet, capping the troubled space agency’s worst week since the 1986 Challenger disaster and reopening the debate over NASA’s competence to carry out its high-tech mission.

Already reeling from the disclosure Tuesday that the $1.5-billion Hubble Space Telescope’s mirror is faulty, officials ordered the grounding after the shuttle Atlantis, scheduled to launch a secret spy satellite July 16, developed a hydrogen leak apparently identical to the one that caused last month’s mission of the Columbia to be scrubbed.

Columbia had to be hauled back into the mammoth Vehicle Assembling Building for repairs, and the same fate seems likely for Atlantis. Most troubling of all, NASA officials still don’t know what caused the Columbia leak.

“We can’t fly. We won’t fly until we understand it and have it fixed,” said William B. Lenoir, NASA’s associate administrator for space flight, who conceded that a return to the assembly building seemed inevitable. “We have not made a decision to roll back, but none of us here can imagine a scenario that doesn’t lead to that,” he said.

The setback could not have come at a worse time for NASA, which is struggling to keep its schedule on course for a high-priority Oct. 4 flight by the shuttle Discovery, which will launch the European Ulysses probe into a polar orbit around the sun. If that launch is not achieved during a 19-day launch period, the next available window will not occur until November, 1991.

It now seems likely that both the Department of Defense launch of a spy satellite in July and the anticipated Aug. 12 launch of Columbia with the star-crossed, $150-million Astro observatory--originally scheduled for launch in 1986--will be pushed back at least until after the Discovery/Ulysses mission.

Because the hydrogen leak has now been observed in two of the three existing shuttles, NASA officials are concerned that the problem is generic and are certain to examine Discovery very closely before permitting a launch.

Meanwhile on Friday, members of Congress excoriated NASA for its problems with the Hubble telescope, arguing that the failure casts doubt on the agency’s ability to handle future high-tech projects like the mission to Mars. Researchers have not been able to focus the telescope as precisely as planned because of an error in the grinding of its 94.5-inch primary mirror, making its sensitivity no better than a ground-based instrument, but much more expensive to operate.

The New York Times on Friday quoted unidentified industry experts as charging that the error could have been detected before launch if NASA had used military equipment routinely employed to test cameras on spy satellites. NASA Associate Administrator Lennard Fisk, appearing Friday before a Senate hearing, refused to confirm or deny the report.

The committee members were furious about the problem with Hubble.

“What does this mean for the rest of the things you want to do? Are we going to keep ending up with techno-turkeys?” asked Sen. Barbara Mikulski (D-Md.), head of the Senate Appropriations Committee that funds NASA. “I think this has seriously hurt the credibility of NASA.”

Fisk countered that management of the space agency has changed radically since the early 1980s, when the Hubble mirror was manufactured. “We know what we are doing,” he said. “Anytime you press technology as far as NASA is willing to press it, occasionally you fall short.”

The last month has been extremely frustrating for NASA technicians as they have tried without success to identify the source of the hydrogen leak that caused the Columbia mission to be scrubbed May 29, six hours before its planned launch.

Workers had just begun loading half a million pounds of supercold liquid oxygen and liquid hydrogen into the shuttle’s rust-colored external fuel tank when sensors in the engine compartment revealed unusually high concentrations of the extremely explosive hydrogen.

Extensive tests over the next few days traced the leak to what is known as a 17-inch disconnect valve that links the fuel tank to the orbiter. The valve, which is manufactured by Parker Hannifin Co. of Irvine, has two major parts--one in the tank and one in the orbiter.

After leak tests at the Kennedy Space Center failed to reveal a leak, technicians two weeks ago removed the valve from the external fuel tank and flew it to Rockwell Corp. in Burbank for testing.

After those tests revealed no leak, Richard Truly, NASA administrator, ordered the corresponding valve in the orbiter removed and flown to Burbank for testing. It is to be replaced with a valve from the fourth shuttle, Endeavor, which is now under construction in Palmdale. No other spares are available.

Because of the problems with Columbia, officials ordered an unusual fueling test of Atlantis two weeks before its scheduled flight.

The test, delayed for a day by lightning, began shortly after 5 a.m. (PDT) Thursday. The leak appeared when technicians were about 5% through the fueling process--the same point at which the leak occurred in the Columbia fueling. Technicians did not find hydrogen in Atlantis’ engine compartment, and the leak appeared to be smaller than that in Columbia. But it was large enough to have forced a scrub if it had been an actual launch.

On Friday, the scientific team in charge of Hubble released a position paper trying to put the Hubble problem in a better light.

The group conceded that the project “has clearly suffered a major setback due to telescope optics that are well below specifications.” Nonetheless, they wrote, “we are convinced that the long-term prospects for completion of the science program are highly encouraging” and that at least 90% of its original goals would be met.