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Possible Satellite Collision Above Pittsburgh A Reminder Of The Risk Of ‘Space Junk’04:09

The Infrared Astronomical Satellite, or IRAS. (NASA)
The Infrared Astronomical Satellite, or IRAS. (NASA)

Two defunct satellites could crash into each other in orbit over Pittsburgh on Wednesday evening, some 560 miles above the Earth.

The satellite-tracking company LeoLabs predicts that an idled NASA telescope and an old Air Force satellite will pass within a few hundred feet of each other just before 6:40 p.m. EST, with a one in 20 chance of colliding.

LeoLabs says it’s also possible the satellites could avoid a collision by just a few dozen feet. Another company, the Aerospace Corporation, put the chances of a crash even higher at one in 10, according to Business Insider.

In a collision, the satellites would disintegrate into orbital debris, or “space junk,” says Brian Weeden, who studies space policy and space debris at the Secure World Foundation.

“Two objects that were going around the Earth in separate circles are suddenly going to become thousands of objects going around the Earth in separate circles,” says Weeden.

Both satellites have been in orbit for decades: The Infrared Astronomical Satellite (IRAS) was launched by NASA, the Netherlands and the United Kingdom in 1983, in the first mission to put an infrared telescope in space, and ran out of fuel that same year. The other satellite, known as GGSE-4, was launched by the U.S. Air Force in 1967 as part of a gravity experiment.

LeoLabs estimates a crash could break the satellites — each more than 10 feet in length and traveling through space at about 9.1 miles per second — into nearly 300,000 separate pieces. But Weeden says a collision would not pose any risk to Earth.

“At that altitude, debris takes years to a couple of decades to come back into the atmosphere,” Weeden says, and your probability of being hit by space junk is very low.

Don’t expect a dramatic explosion, either, Weeden adds: “You're not going to see a fireball in space because there's no oxygen.”

But the potential crash highlights the long-term risk that accumulation of space debris poses to satellites used for weather forecasting and communication.

There are more than 20,000 objects currently in orbit, the vast majority of which are no longer operational, ranging in size from as small as a softball to larger than a school bus. That’s in addition to another 500,000 to 900,000 even smaller fragments, according to estimates from NASA and the European Space Agency.

And every additional piece of debris raises the risk of a collision for the roughly 2,000 functional satellites in orbit.

“All that debris is going to make orbiting in space and operating satellites costlier, more risky,” Weeden says. Over time those costs could become restrictive, since “orbit debris is concentrated in a few altitude regions that we've traditionally used a lot. Those regions and those altitudes might become unusable,” he says.

Weather and imaging satellites, typically located in low Earth orbit, are especially at risk, NPR reports. And the amount of debris is projected to grow amid an increase in private space ventures.

No fix for the problem has been tested in space, though scientists in Japan and Europe have demonstrated approaches to reign in the problem with magnets and nets. But Weeden says the technology isn’t the biggest hurdle.

“The really hard part is who pays for it?” he says. “A lot of these satellites and dead debris are left over from government missions that happened decades ago. And there's not a lot of interest from governments in paying more money to go up and remove all this stuff.”

There is a glimmer of hope for space cleanup: In D­ecember, the European Space Agency commissioned the first orbital debris clean-up mission, to be carried out by a robot starting in 2025. That mission, ClearSpace-1, is projected to cost $130 million.

Francesca Paris produced and edited this interview for broadcast with Kathleen McKenna. Paris also adapted it for the web. 

This segment aired on January 29, 2020.

Peter O'Dowd Twitter Senior Editor, Here & Now
Peter O’Dowd has a hand in most parts of Here & Now — producing and overseeing segments, reporting stories and occasionally filling in as host. He came to Boston from KJZZ in Phoenix.


Francesca Paris Twitter Producer
Francesca Paris is an associate producer and editor for Here & Now.


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