NASA Scrubs Launch of Discovery : Shuttle Flight: Problem in auxiliary power unit puts Hubble telescope flight on hold for one or two weeks.

NASA scrubbed the launch of Discovery with the $1.5-billion Hubble Space Telescope today when a problem developed four minutes before liftoff in a unit that supplies power to the shuttle’s wing and tail surfaces.

The launch will be attempted again in one to two weeks, said launch director Bob Sieck. A more precise time will be determined on Wednesday.

Sieck said a preliminary review indicates a valve on the auxiliary power unit did not respond properly, allowing too much fuel to go through the power system.

Engineers were working to determine the extent of the problem even before the five astronauts emerged from the cockpit where they had lain on their backs for more than three hours.

NASA said at an early afternoon briefing that the faulty APU will have to be removed from the launch vehicle.

The scrub was a disappointment to the hundreds of astronomers who had gathered at Kennedy Space Center to watch the launch of Discovery and the telescope that it carries in its cargo bay.

About 150 relatives of Edwin P. Hubble, the astronomer for whom the telescope is named, headed for a pool party following the scrub.

“These things have happened. It’s part of the game,” said Harvey Hubble IV, a 60-year-old retired businessman from North Palm Beach who organized the family gathering. “We would much rather you stop the count than do something foolish.”

The Hubble Space Telescope, the most expensive unmanned spacecraft ever built, has been waiting to take its place in space since 1983--delayed by technical problems and the 1986 Challenger explosion.

Diller said NASA was disappointed at the latest delay “but the stars will be here tomorrow.”

Two other shuttle launches have been delayed because of auxiliary power units.

All the other worries, about weather at the launch site and at emergency landing sites overseas had been swept away and the countdown proceeded without a hitch to the four-minute mark pointing toward a launch at 8:47 a.m. EDT.

But then Commander Loren J. Shriver noticed that one of the APUs was running erratically and reported the fact to launch control.

The three APUs steer the ship’s three engines, control the movements of flaps on the wings and the rudder, lower the main and nose landing gears and provide the hydraulics for the main landing gear brakes.

The Missouri-born Hubble discovered during the 1920s that the universe is expanding. His findings gave rise to the theory that the universe was created about 15 billion years ago by a tremendous explosion known as the Big Bang. He died in 1953.