How OneWeb, SpaceX Satellites Dodged a Potential Collision in Orbit

"Two satellites from the fast-growing constellations of OneWeb and SpaceX's Starlink dodged a dangerously close approach with one another in orbit," reported The Verge, citing representatives from both OneWeb and the U.S. Space Force.

UPDATE (April 22): SpaceX strongly disputes OneWeb's characterization of the event.

Below is the Verge's original report: On March 30th, five days after OneWeb launched its latest batch of 36 satellites from Russia, the company received several "red alerts" from the US Space Force's 18th Space Control Squadron warning of a possible collision with a Starlink satellite. Because OneWeb's constellation operates in higher orbits around Earth, the company's satellites must pass through SpaceX's mesh of Starlink satellites, which orbit at an altitude of roughly 550 km.

One Space Force alert indicated a collision probability of 1.3 percent, with the two satellites coming as close as 190 feet — a dangerously close proximity for satellites in orbit. If satellites collide in orbit, it could cause a cascading disaster that could generate hundreds of pieces of debris and send them on crash courses with other satellites nearby...

Space Force's urgent alerts sent OneWeb engineers scrambling to email SpaceX's Starlink team to coordinate maneuvers that would put the two satellites at safer distances from one another. While coordinating with OneWeb, SpaceX disabled its automated AI-powered collision avoidance system to allow OneWeb to steer its satellite out of the way, according to OneWeb's government affairs chief Chris McLaughlin... SpaceX's automated system for avoiding satellite collisions has sparked controversy, raising concerns from other satellite operators who say they have no way of knowing which way the system will move a Starlink satellite in the event of a close approach.

Already?

[fluffernutter]

This happens already and they have, what, 5% of the final plan up there?

Re:

[bill_mcgonigle]

> This happens already and they have, what, 5% of the final plan up there?

Yeah, and so far only SpaceX has collision-avoidance capabilities. This can't persist - a standard will have to be established so all the satellites going up can cooperate with each other as we utilize, then colonize space.

I would guess SpaceX will freely license any patents but I haven't seen nor asked.

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[Ol Olsoc]

> This happens already and they have, what, 5% of the final plan up there?

Yeah, and so far only SpaceX has collision-avoidance capabilities. This can't persist - a standard will have to be established so all the satellites going up can cooperate with each other as we utilize, then colonize space.

I would guess SpaceX will freely license any patents but I haven't seen nor asked.

Nothing will happen until we make a mess out of LEO. And yes - it will happen. Considering the number of sats being put up, it is inevitable. We might even get to see our first Kessler event.

Around here at least, the apparent competition has had some groups putting up more fiber in addition to that already put up, but never lit. This mini-Dyson sphere Musk et al want to place is a dead end, and will make a mess in the end

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[caseih]

Most satellites can be maneuvered including OneWeb satellites. Only SpaceX has on-board AI to do collision avoidance, which could turn out to be a problem since it makes their satellites less predictable when other companies are trying to move their satellites out of the way. From the article:

While coordinating with OneWeb, SpaceX disabled its automated AI-powered collision avoidance system to allow OneWeb to steer its satellite out of the way, according to OneWeb's government affairs chief Chris McLaughli

Re:

[fluffernutter]

How many people will they need to employ to manage this once there are 2000% more satellites up there? What happened to "the sky being a really, really big place"?

No worries

[quonset]

they have no way of knowing which way the system will move a Starlink satellite in the event of a close approach.

No worries. Musk will upload his self-driving software to the satellites. Everything will work perfectly.

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[SirSpanksALot]

It's already there... OneWeb had them turn it off because they didn't want to make a move that would conflict with the self driving collision avoidance.

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[93 Escort Wagon]

Seems like this is a situation where all the players should have access to (and be using) the same algorithms, rather than SpaceX and OneWeb having to sort this stuff out on the fly.

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[LazyBoot]

Sounds like they really should have something like TACS. So it's not just algorithms on each satellite, but them automatically mutually agreeing on what actions to take. "you go that way, I go this way" type deal.

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[LazyBoot]

mistyped TCAS... my bad

Another thing they should have access to

[raymorris]

That would be a good thing to have.
This part of the summary got me thinking of something else that would be good to have:
--
Multiple red alerts ...
Space Force's urgent alerts sent OneWeb engineers scrambling to email SpaceX
--

When you're scrambling due to red alerts, it would be cool to have some kind of communication that helps conversations go faster than email does. Our phones should have some kind of app that does voice recognition and sends messages back and forth in real time. So like you talk

Chain reaction

[NewtonsLaw]

I recall seeing a video many years ago in which a room was filled with mouse-traps that had ping-pong balls on them. So long as none of the traps were activated, everything was fine. However, when just one of the traps went off, they almost all went off due to the chain-reaction that followed when one ping-pong ball was thrown onto a neighbouring mouse-trap which caused it to trigger -- throwing its ball onto the next, etc, etc.

The video was originally used to demonstrate the effects of a run-away nuclear

Re:

[NewtonsLaw]

I mean runaway fission reaction of course (duh!)

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[Iamthecheese]

Kessler syndrome, which you're describing, isn't likely to be very severe or long lasting due to the low orbits these satellites occupy. In a couple of years they'll all burn up anyway. Without station keeping (as for a piece of debris) that will happen faster.

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[Actually, I do RTFA]

I liked that video. Even more fun was the COVID-19 based one where they used it to show the spread of COVID. Then made a similar huge array spaced six feet apart and showed a much smaller feedback loop and total triggered mousetrap. Obviously, the details of "launches a ping pong ball" and "spreads aerosol particles" is different, but it was very effective in conveying the message anyway.

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[thegarbz]

I don't understand. Can you explain it in simpler terms, maybe with pop culture references, in video form starring Sandra Bullock and George Clooney.

The Kessler Syndrome

[jhecht]

The satellite version of the chain reaction is called the "Kessler syndrome," and it's a very real problem. Satellites in low earth orbit move faster than 10 kilometers per second, so when two crash they can produce a couple thousand pieces of space debris -- shrapnel moving at similar speeds that are big enough to disable or destroy another satellite. It already happened in 2009 when an operating Iridium satellite collided with a defunct Russian communication satellite. https://en.wikipedia.org/wiki/... [wikipedia.org]. In 2019 an early SpaceX Starlink satellite almost collided with the European Space Agency's Aeolus satellite https://www.cnet.com/news/esa-... [cnet.com] . Computer models show that a series of satellite collisions -- and collisions of shrapnel with other satellites -- can produce a cascading chain reaction that makes low earth orbit unusable for satellites. There's real science behind the movie Gravity!

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[account_deleted]

Comment removed based on user account deletion

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[John_Sauter]

I recall seeing a video many years ago in which a room was filled with mouse-traps that had ping-pong balls on them. So long as none of the traps were activated, everything was fine. However, when just one of the traps went off, they almost all went off due to the chain-reaction that followed when one ping-pong ball was thrown onto a neighbouring mouse-trap which caused it to trigger -- throwing its ball onto the next, etc, etc.

I saw that video also. It was Disney's "Our Friend the Atom". The mouse trap is first introduced at 31:30, but you probably remember the shot at 36:00 or 38:30. Here is the link to YouTube: https://www.youtube.com/watch?... [youtube.com] .

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[Ol Olsoc]

I recall seeing a video many years ago in which a room was filled with mouse-traps that had ping-pong balls on them. So long as none of the traps were activated, everything was fine. However, when just one of the traps went off, they almost all went off due to the chain-reaction that followed when one ping-pong ball was thrown onto a neighbouring mouse-trap which caused it to trigger

The sitution with satellites is called a Kessler event. And the huge number of satellites put up for serving people their porn is a prime candidate for that.

The results of satellite collisions place a lot of particles in a lot of slightly different orbits. So in a crowded shell, a collision between two can make a lot of small pieces, starting that chain reaction.

Now some muskovite will chime in about the perfection of Spacex's collision avoidance system. Problem is a non orbital object, say a meteor,

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[anoncoward69]

That's actually quite a thought, and countries like NK could probably be quite capable of pulling off something like launching a rocket full of a bunch of junk up into the starlink orbital plane and deploying the junk to let the chain reaction ensue.

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[Ol Olsoc]

That's actually quite a thought, and countries like NK could probably be quite capable of pulling off something like launching a rocket full of a bunch of junk up into the starlink orbital plane and deploying the junk to let the chain reaction ensue.

The ridiculously low tech method of taking out satellites is part of the reason some old school tech like LORAN has been turning back on. Russia and the US aren't likely to knock out each others sats because we each are pretty dependent on them, but yeah, NK is a prime candidate for doing something nasty. As soon as they can reach orbital velocity, all bets are off.

There's an old adage that our first war in orbit will be our last for many years. That is not incorrect.

If satellites collide in orbit,

[PPH]

it could cause a cascading disaster that could generate hundreds of pieces of debris

and ultimately result in a movie named Gravity.

You got OneWeb on my SpaceX

[bobstreo]

You got SpaceX on my OneWeb.

Bravissimo

Yeah

Cascade Effect?

[Arzaboa]

This sounds like uber conservative analytical nuttiness to me. Lets put it this way. You ever played pool and thought to yourself, "If I just hit that large mass of balls, one just HAS to go in!" You might get one in 10% of the time. That is on a table where we are talking about inches and feet. It sounds to me like these folks have seen that movie Gravity one too many times.

Now in reality, no one wants another 2,000 broken satellite pace parts moving around at 17,000 mph in low earth orbit. That would certainly make it difficult to use those altitudes.

This article here describes the reality of all of this fairly well -> https://www.theguardian.com/sc... [theguardian.com]

--
Progress is man's ability to complicate simplicity. - Thor Heyerdahl
   

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[Train0987]

If you hit that mass of balls hard enough such that they never stop from the friction of the felt eventually every one of the balls will find a pocket and go in.

A collision is a matter of time

[couchslug]

So are more collisions. Measures will eventually be taken to deal with the debris, but that's not a public problem, it's a rich space user problem.

Space Insurance?

[Jzanu]

Who pays for the damage when something does hit? Imagine one of these more recently launched micro-satellites hitting a a multi-million cost major communications satellite. The loss is not negligible either in hardware and even greater lost services.

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[AmiMoJo]

Not the satellite owner. It might be possible to sue them if negligence can be shown, but even that might be very difficult if they are in a different jurisdiction.

Nobody is going to pay to clean up the debris either.

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[r2kordmaa]

If your satellite gets hit by space debris it's your own damn problem. And it doesn't matter what the relative cost of two pieces of hardware colliding are, it's the job of the one that can avoid a collision to do so, a cubesat generally has no capacity to modify it's orbit, let alone on short notice. So if a major comms satellite shares an orbit with a microsat(which generally isn't the case), it's usually job of the major sat to get out of the way.

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[R3d M3rcury]

it's the job of the one that can avoid a collision to do so

What if they both do? There's where it gets interesting...

The summary mentioned that the Starlink satellites can maneuver to avoid hitting other satellites. But the folks at SpaceX turned it off so that the satellites would behave predictably and so OneWeb could move the satellites that were in danger out of the way.

So you have two satellites that are going to be dangerously close. One goes up and so does the other, since they're both programmed to increase their altitude in this event. They're still go

Re:

[Anubis IV]

At least with these recent constellations, they’re in low earth orbit, whereas most major communication satellites are in geostationary orbit at a SIGNIFICANTLY higher altitude.

That's why they launch so many

[ayesnymous]

So if a few of them crash, the others will pick up the slack.

Who cares

[nospam007]

SpaceX is sending 60 of them up almost every week now.

eLoran

[FarmerInTheDellCompu]

Kessler syndrome.

No GPS
No satellite internet
No space station
Oh my

At least if you will be in a commercial plane during a GPS outage of any kind, it would be nice if eLoran were in place.
 

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[anoncoward69]

GPS will probably be fine, they are in a much higher orbit than the starlinks. It could definitely pose a threat to the space station and getting people to/from it though. I believe the space station is in a lower orbit than the operational orbit of the starlinks. So if there were chain reaction collisions, all that crap could come raining down on the space station as it deorbits over time.