A new radar system will track 250,000 tiny pieces of space junk. It may help prevent snowballing collisions that could cut off our access to orbit.
LeoLabs is based in San Francisco, though its new device is in New Zealand. It will make data about an estimated 250,000 bits of tiny space junk available to private companies for the first time.
Over 100 million of bits of junk surround Earth, from abandoned satellites, spacecraft that broke apart, and other space missions.
These bits of debris circle in low-Earth orbit (LEO): the altitudes between 160 and 2,000 kilometers (99 to 1,200 miles). That's where most human-made space objects congregate, including the International Space Station and thousands of satellites.
Each piece of space debris, no matter how small, travels at speeds high enough to inflict catastrophic damage to vital equipment. A single hit could be deadly to astronauts on a spacecraft.
Chunks of debris zip around Earth at more than 17,500 mph — roughly 10 times the speed of a bullet. That's a threat to any satellite or spacecraft the junk might hit, and every collision could make the problem worse, since it would fragment satellites into smaller pieces.
If the problem gets extreme, a disastrous chain of collisions could spiral out of control. This possibility is known as a Kessler event.
Theoretically, one collision could create and spread bits of junk that then cause another collision, which in turn begets more debris and leads to a chain of crashes. Eventually, Earth would wind up surrounded by an impassable field of debris.
Donald J. Kessler, who worked for NASA's Johnson Space Center, calculated in 1978 that it could take hundreds of years for such debris to clear up enough to make spaceflight safe again.
Ceperley said the risk of a Kessler event is very low, but "each time there's a big collision, it's a big change in the LEO [low-Earth orbit] environment."
In 2009, an American spacecraft accidentally collided with a Russian one, increasing the amount of large debris in low-Earth orbit by about 70%.
"Because of that, now there's sort of a debris belt," Ceperley said.
India also generated thousands of bits of debris in March when it blew up one of its spacecraft in an anti-satellite missile test.
NASA can equip spacecraft with debris shields, but those can only withstand impacts from objects smaller than 1 centimeter (half an inch).
So millions of objects larger than that still pose an ongoing threat.
NASA works with the Department of Defense to track some dangerous space junk, mapping objects' orbits so that satellites can maneuver around them. But any debris smaller than 10 centimeters has so far proved too tiny to track.
That's the problem LeoLabs hopes to address.
In the last few years, an explosion of private satellite operators and rocket companies like SpaceX has created new demand for data on orbital debris. LeoLabs provides that information using a worldwide network of debris-tracking radar systems.
"Just a few years ago, the new space revolution really kicked into gear," Ceperley said. "That enabled companies like us to get into the market."
The newest addition to that network, the Kiwi Space Radar in New Zealand, tracks objects smaller than 10 centimeters.
It joins LeoLabs' radar network to provide real-time information about objects in low-Earth orbit.
"Radars send out pulses of radio waves up into the sky and then listen for echoes that come back down off the satellite and space debris," Ceperley said. "It's sort of like bats and echolocation. They use little chirps of sound. Instead, we use chirps of radar waves."
The new radar's high frequency can detect objects as small as 2 centimeters wide.
A novel design makes the system sensitive to small objects: Long rows of a few hundred identical transmitters and receivers send precisely timed signals, working together to track an object's movement above Earth.
LeoLabs plans to build three more such radar arrays to track tiny objects as well.
Eventually, the company hopes to put an array near the equator and two others closer to each of Earth's poles.
"Track it all better, and reduce the number of collisions — that's what we're focused on," Ceperley said.
Eventually, Ceperley hopes that his company's data can help future "tow-truck satellites" that could be launched to clean up space debris.
The European Space Agency (ESA) has already planned a clean-up mission to capture one of its defunct satellites, drag it into Earth's atmosphere, and burn it. Private companies have explored similar concepts for larger-scale clean-up.
Using LeoLabs' data, private debris-removal companies could calculate a particular satellite's risk level of a catastrophic collision, Ceperley said.
The ability to make those assessments accurately could help such companies sell their services, he added: "They can set prices and justify prices based on those numbers and hopefully make their service very routine so that it's a regular part of satellite operations."
"A lot of the risk comes from this small debris, all this stuff that's never been tracked before. Nobody's got a good solution to clean that up," Ceperley said.
"Let's make sure we don't make more of it," he added.
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