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  sci-tech > space > story pagecorner  

Space scavenger pulls data from 'lost' satellite

WIRE spacecraft
A photo of the WIRE spacecraft prior to its March 5 launch clearly shows the star camera

CNN's Greg Lefevre looks at a crippled satellite still able to yield valuable data
Windows Media 28K 80K

August 4, 1999
Web posted at: 4:57 p.m. EDT (2057 GMT)

In this story:

'We had nothing to lose'

A completely new mission

Like 'drinking from a firehose'


By Greg Lefevre
San Francisco Bureau Chief

(CNN) -- UC Berkeley astronomer Derek Buzasi is turning space trash into scientific treasure, salvaging a trove of scientific data from a NASA satellite that was once considered a total loss.

Buzasi's astronomical odyssey began when the NASA space telescope called Wide Field Infrared Explorer (WIRE) was launched last March.

The main telescope's cover came off early, damaging it and rendering it useless.

But Buzasi had an idea.

"I was driving home thinking about what could we possibly salvage from this. What else is on board this spacecraft?"

That's when he realized that a small guiding telescope designed to help steer the satellite could be put to other uses.

Usually called a star camera, it aims at known stars and helps scientists orient the satellite in the three-dimensional void of space.

"So I immediately picked up the phone and called the manufacturer and asked them to tell me about its capabilities," he says.

'We had nothing to lose'

At the other end was Perry Hacking, the principal investigator at NASA's WIRE Project at CalTech in Pasadena, California.

"We all thought we had nothing to lose and so we thought it was a good experiment to try," Hacking said.

The small guiding scope is a two-inch model about the same size as those sold in astronomy stores, although it is significantly more sophisticated.

It's really good only for looking at the brighter stars.

But, clear of the Earth's atmosphere, perched in outer space, it's very good for that.

So far Buzasi has studied stars in the constellations Ursa Major (Big Dipper) and Centaurus. Buzasi examines the stars' oscillations.

Stars, he says, vibrate at a high frequency, like ringing bells.

"The frequencies, wavelength, at which the star vibrates tell you something about how the star is built and it allows us to actually see into the interior of the star," he says.

Buzasi came up with the idea of using the star camera to gather data   

Buzasi will determine the star's age, how dense it is and what it's made of.

A completely new mission

The original WIRE project was launched on time and under its $80 million budget. The launch went as planned. The spacecraft performed perfectly, and still does. But a little-known bug in a computer chip caused the protective shield covering the telescope to blow off prematurely.

That caused a series of problems. The super-sensitive telescope was exposed to the sun. Hydrogen ice that was supposed to keep the telescope cool instead spewed into space and the telescope failed.

NASA by that time had spent $73 million and was prepared to declare the project a loss.

That's when Buzasi called.

In just a few weeks time, engineers at Goddard Space Flight Center in Maryland steered the satellite in a new direction and converted it to perform a completely different mission.

Hacking adds engineers at Cal Tech wrote entirely new software to make the data coming from the small telescope useful for Buzasi's project.

"We had different targets, different objects to look at than we originally planned," Hacking says. "But there's quite a bit more that had to go into getting those data to the ground and then the analysis of them on the ground in order to get to the results you've heard about."

Like 'drinking from a firehose'

Hacking calls the results terrific.

"This is one heck of a consolation prize," he says.

The smaller scope makes about 10 observations of a star per second, for about 40 minutes each day.

The Big Dipper
The Big Dipper   

Buzasi is getting plenty of data.

"I'm getting something like 750,000 observations a day. And so keeping up with that is a little bit like drinking from a fire hose, and I'm behind on reducing the data."

In just a few months he's learned plenty. He studied Alpha Ursa Major, the brightest star in the Big Dipper. He found it's over four times the mass of our sun and is about 120 million years old. And expanding rapidly.

"It's actually on its way to becoming a giant. It's just starting to enlarge."

Many satellites use so-called spotting scopes to aim at the stars and keep the satellite positioned.

Astronomers now wonder if more of those same scopes could serve a dual purpose, sending back scientific data as well.

WIRE mission to study galaxy formation declared a loss
March 9, 1999
Tiny WIRE satellite begins giant galactic mission
March 5, 1999
WIRE spacecraft launch rescheduled for Thursday
March 3, 1999
NASA to explore history of universe
March 1, 1999

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