NASA scientists and engineers at Goddard Space Flight Center designed the International Ultraviolet Explorer, a space-based telescope, to last three years but hoped for five. Last week, it turned 10.
Launched on a Delta rocket Jan. 26, 1978, the IUE satellite measures six feet by six feet and moves at the same pace as Earth's rotation, so that, in effect, it hovers over a point on Earth's surface. The satellite "tells us from whence we come," said Yoji Kondo, project scientist at the Goddard Center in Greenbelt. "As Carl Sagan says, we are all made of star stuff."
Yielding more than 70,000 exposures of stars, supernovae and such other cosmic tenants as galactic halos, the space telescope has been the workhorse for more than 1,400 research articles. It provided the first and last complete space pictures of Halley's Comet, and it was the first space telescope to capture photos of a supernova that appeared last February.
Despite the telescope's discoveries and firsts, its longevity has not been without tense moments. A guidance system almost failed in August 1985. Henry Hoffman, chief of the Guidance and Control Branch of the Space Technology Division at Goddard, saved the telescope from certain death. In fact, some Goddard employees have nicknamed Hoffman the "Satellite Doctor."
Working with a computer linkup from the ground, Hoffman's engineering team loaded the satellite's on-board computer with new software that allowed the satellite to replace a malfunctioning gyroscope that controls navigation. The satellite stabilized.
"It's like doing bypass surgery from 22,000 miles away," Hoffman said.
Fog, smog, light and clouds diminish the abilities of Earth telescopes, but space telescopes, which are above much of those obstructions, can provide astronomers with impressive pictures of the universe. The IUE works 24 hours a day, unlike its cousins on the ground -- which see only on clear nights.
The satellite cost $250 million to create and launch, and it requires about $25 million annually for maintenance, Kondo said. The National Aeronautics and Space Administration shares the costs as well as viewing time with the European Space Agency and the British Science and Engineering Research Council.
Astronomers say the mission of the IUE could last a while longer.
"We are talking six or seven more years; it's not possible to predict exactly," Kondo said. "From the projections, it could run to the mid-'90s."