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Defunct Soviet satellite and Chinese rocket body have 1-20% risk of colliding in Low Earth Polar orbit over Antarctica
@LeoLabs, Inc.:
We are monitoring a very high risk conjunction between two large defunct objects in LEO. Multiple data points show miss distance <25m and Pc between 1% and 20%. Combined mass of both objects is ~2,800kg.Object 1: 19826Object 2: 36123TCA: Oct 16 00:56UTCEvent altitude: 991km pic.twitter.com/6yWDx7bziw
Also picked up in Newsweek and Forbes but in both cases they're just repeating this LeoLabs tweet with additional context.
This seems like a low risk, but even a 1% chance of collision / 25 meter miss distance is very high by space standards. The company I work for operates satellites and we have received close approach notifications when our satellite has a 0.01% chance of collision, with a projected miss distance of 1 kilometer.
Orbital altitude of 1000km is also concerning, because many many satellites are at lower altitudes. A debris cloud caused by this could put everything below it, including the ISS, at increased risk of collision.
Sidebar conversation: What do you do there?
I work on ground control software. We have a network of ground stations around the world plus command & control running in AWS Govcloud.
(side note: we're hiring! I don't want to link to the company I work for in a public post but PM me if anyone is interested. Seattle-based, open to remote within the US for strong candidates. Due to US government restrictions we're only able to hire US Citizens or permanent residents)
In January LEOLabs also monitored a close-pass between two scientific satellites launched in the 60's and 80's. The calculated miss distance was < 20m, and one the satellites was physically quite large, with the other potentially having booms extending 18+ metres in either direction.
People who say "space is big, Kessler syndrome isn't anything to worry about" don't get it. It's not a volume or size problem, it's an intersectionality problem. With more and more satellites going up, there's going to more and more of these close passes, and a small portion of them are going to create huge debris-generating events that could block off entire orbits for decades.
Space is really big, and satellites are really small, but collisions are a birthday problem, which have a nasty habit of brutally telescoping safe-seeming odds.
With mounting numbers of objects, we need a way to remove defunct objects from orbit, or a Kessler cascade is an eventuality, not a possibility.
Birthday problem was the term I was looking for! Thanks.
In 2009 two satellites collided
No indication of collision: https://twitter.com/LeoLabs_Space/status/1316919600160903168
Dodged a bullet this time.
Frankly I'm betting these sorts of conjunctions are going to become a multiple-times-a-year occurrence as soon as next year.