Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, April 10, 1990 TAG: 9004100692
SECTION: NATIONAL/INTERNATIONAL PAGE: A/2 EDITION: EVENING
SOURCE: Associated Press
DATELINE: CAPE CANAVERAL, FLA. LENGTH: Medium
NASA decided to wait at least until Thursday before trying again, launch commentator George Diller said.
As the five astronauts began emerging from the cockpit where they had lain on their backs for more than three hours, engineers worked to determine the extent of the problem with the Auxiliary Power Unit.
The scrub was a disappointment to the hundreds of astronomers who had gathered at the Kennedy Space Center to watch the launch of Discovery and the telescope that it carries in its cargo bay.
"It's a real downer. You could see it couldn't be a more beautiful day," NASA scientist Stephen Maran said.
Hubble, 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."
If the power unit has to be replaced entirely, it would mean a delay of at least several days, said Keith Hudkins, chief of NASA's shuttle orbiter division. Replacing a part, however, could be done in a day or so.
Two other shuttle launches have been delayed because of auxiliary power units.
"There'll be something changed out," Hudkins said. "Something's broken that will have to be switched."
The space telescope's batteries will hold their charge through Friday, but after that would have to undergo an eight-day recharge on The three units 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 ground. Once Hubble is in orbit, its solars panels will keep its batteries supplied with power.
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 Shriver noticed that one of the power units was running erratically and reported the fact to launch control.
The three units 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.
They are partly, but not totally redundant - that is, each movable part is governed by two units. The pumps are considered so critical that mission rules require landing as soon as possible if any one of the three fails.
The 35th shuttle mission is to take Discovery to an altitude of 380 miles, the highest a shuttle has ever gone, so the telescope can operate safely above Earth's obscuring atmosphere.
Hubble will be capable during its 15-year working lifetime of detecting objects 50 times fainter and with 10 times greater clarity than the best ground-based observatory.
It will allow astronomers to study stars and galaxies so distant that their light has been traveling to Earth for 14 billion years. It may shed light on how and when the universe was formed, solve the mysteries of quasars, pulsars and black holes, even find stars with planets that could conceivably support life.
The National Aeronautics and Space Administration said it might release its first telescope image - of an open star cluster in the constellation Carina - as early as four days after Hubble is deployed.
"Never before have we had a telescope, an observatory with this capability," said NASA's chief scientist, Lennard Fisk, "and it will not be surpassed perhaps until we start to establish observatories on the moon some day.
"So we have an opportunity now to really unlock the secrets of the universe in ways that have not been available to us before."
Shriver's crewmates are Marine Col. Charles Bolden Jr., the pilot, and mission specialists Steven Hawley, Bruce McCandless and Kathryn Sullivan.
Discovery will follow Hubble for its first few days in orbit until NASA is confident the telescope is functioning properly. The telescope is expected to start providing scientific data by satellite in a month or two.
by CNB