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Satellite survives close encounter with space junk
Shuttle crew not in danger
August 12, 1997
Web posted at: 11:17 p.m. EDT (0317 GMT)In this story:
- 'This was a moment of excitement'
- 'We point the whole shuttle'
- Mission nearing halfway point
- Related stories and sites
CAPE CANAVERAL, Florida (CNN) -- While the crew of the Discovery took pictures Tuesday of the Hale-Bopp comet with an ultraviolet telescope, a satellite trailing the shuttle came within 1 1/2 miles of a 500-pound piece of space junk.
The satellite, which is being used to measure ozone, was 51 miles behind the Discovery when it had its close encounter with an abandoned rocket motor. The shuttle crew was not in any danger, German mission manager Konrad Moritz said.
The U.S. Space Command, which tracks junk in orbit, warned NASA that a discarded rocket motor was in the neighborhood. And as it neared, engineers predicted the two would be anywhere from a half-mile to 3 1/2 miles apart.
The German-built satellite weighs 7,700 pounds and cost tens of millions of dollars. The rocket motor is one of 8,500 pieces of orbiting objects being tracked by the Space Command, most of them junk.
John Holliman talks to Steve Robinson, mission specialist.
A collision between the two, both traveling at 17,500 miles an hour, would have been disastrous. And the uncertainty made for some anxious moments for scientists on the ground, who watched on computer screens as the two drew near each other.
Ground controllers were prepared to fire tiny thrusters on the satellite to maneuver it out of the way, but it was not necessary.
'This was a moment of excitement'
"We saw that we are still transmitting, so our spacecraft is fine," Moritz said. "This was a moment of excitement."
There is no danger of the motor coming close to the 184-mile-high satellite again, according to NASA spokesman Kyle Herring. The astronauts plan to retrieve the satellite on Saturday, two days before their mission ends.
The spent rocket motor was used in the unsuccessful launch of a communications satellite that was carried up on a shuttle in 1984. Coincidentally, the platform on which the satellite's ozone-mapping telescopes are flying was on that mission, too.
"Now we are meeting this guy again," Moritz said. "Isn't that the story?"
Meanwhile, the Discovery's crew spent Tuesday taking more pictures of the Hale-Bopp comet with an ultraviolet telescope mounted on a shuttle window.
On Discovery's darkened lower deck, astronaut Steve Robinson focused a 7-inch (18-centimeter) diameter ultraviolet telescope through a small porthole in a cabin hatch to catch a glimpse of the comet.
'We point the whole shuttle'
It was the second time the astronauts had viewed Hale-Bopp since they rocketed into orbit last Thursday.
The $600,000 telescope is probing the chemical composition of the gases given off by the celestial snowball, which was described by astronomers as the great comet of 1997.
"We point the whole shuttle, we don't just point the telescope," Robinson said. "We point the whole shuttle at the comet," enabling a digital camera to look at the ultraviolet spectrum.
"And that," said Robinson, "is something we cannot do from Earth because the atmosphere protects us earthlings and everything on the Earth from the ultraviolet rays of the sun. But it also keeps us from learning about the ultraviolet spectrum of astronomical bodies like the comet Hale-Bopp."
The comet is currently 270 million miles (430 million km) from Earth and approaching an asteroid belt. It is not due back in the vicinity of the sun until the late 44th century.
Mission nearing halfway point
The astronauts also conducted more tests with a laboratory platform designed to withstand vibrations from the spacecraft.
The Discovery and its six-member crew are nearing the halfway point of their mission. The shuttle is due to return to Earth at Florida's Kennedy Space Center on Monday.
The Associated Press and Reuters contributed to this report.
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