Huge NASA telescope may be headed for fiery descent to splash landing

The observatory was launched in 1991

January 14, 2000
Web posted at: 7:49 p.m. EST (0049 GMT)

From Space Correspondent Miles O'Brien

GREENBELT, Maryland (CNN) -- After nearly nine years in space, a 35,000 pound NASA observatory in low-Earth orbit may be destined for a fiery descent into the Pacific Ocean near Hawaii this spring.

"We have formed a team to see if we need to bring it down in a controlled reentry," says Preston Burch, deputy program manager for space science operations at NASA's Goddard Space Flight Center.

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In early December, the $600 million Compton Gamma-Ray Observatory lost one of its gyroscope systems, leaving it with the minimum of two required to conduct scientific observations. Engineers running the program at Goddard are uncertain if they need two operative gyroscopes to safely steer the satellite away from population centers.

The question is: Can we tolerate another failure?" said Burch. "If the answer is yes, then we can continue (in orbit) indefinitely."

But if the answer is "no," NASA will try to steer Compton down into the Pacific near Hawaii on March 14.

"The debris field is significant," according to Burch. According to engineering estimates, it will be 26 kilometers (16 miles) wide by 1,552 kilometers (962 miles) long -- putting approximately 40,000 square kilometers (24,800 square miles) of ocean in harm's way.

Launched from the space shuttle Atlantis on April 5, 1991, the Compton Gamma-Ray Observatory was designed to orbit for at least two years gathering information on electromagnetic radiation -- shedding light on the origins of the universe. While the scientific observations continue, the staff -- and the funding -- are currently very lean.

Compton is the heaviest unclassified satellite ever deployed by a space shuttle. The Hubble Space Telescope, launched in April of 1990, weighs 10,000 pounds less, despite being larger.

Unlike Hubble, Compton was not designed to be serviced by astronauts in its 270 mile orbit.

Engineers are busy culling old records and faded memories to determine if Compton can fly on safely. On February 16, they will report their findings to NASA managers. Unless they can allay concerns about an uncontrolled descent (a la Skylab), they will decide at that time to bring the telescope down on March 14.

"We are putting a full court press on this." says Burch. "This is as fast as we can make it happen."