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SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

forbes.com

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Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#171

Post by greglindahl »

Rapzid wrote: post #98
saagarjha wrote: post #20

Of course, inside the article it’s explained that SpaceX didn’t “refuse” to move the satellite, they were politely asked to do so and declined for reasons the author is unaware of. Possibly because they couldn’t move the satellite or had a higher collision tolerance.

I think a major topic missed is this 1 in 1000. I think the only chance involved in this, practically speaking, is that the ESAs data about the orbits had enough error in it to not be sure there would be no collision. This is a lot different than rolling dice or betting on black. Likely there was or was not going to be a collision; run it 1 million times and the results would always be the same. Perhaps Space-X had m…

Do you think everyone agrees on those odds? There are other organizations that model collisions and they usually disagree.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#172

Post by greglindahl »

WalterBright wrote: post #159

The long term solution would be to establish some form of property rights over particular orbits. Then, to use a particular orbit, one must pay the market rate for it.

Deorbiting satellites make that a hilarious proposal.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#173

Post by greglindahl »

pergadad wrote: post #18
floatingatoll wrote: post #5

> In 2018, ESA performed 28 #collisionavoidance manoeuvres across its fleet.

How many maneuvers can such a satellite do with it's limited fuel?

The Aeolus satellite needs to be reboosted on occasion due to atmospheric drag. So, potentially, it was free.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#174

Post by FireBeyond »

manicdee wrote: post #150
FireBeyond wrote: post #111

Earlier quoted context omitted.

... typically of dead satellites or debris that is unable to move itself. ESA had a weather satellite in orbit, SpaceX actively moved an active satellite _into_ the same orbit as ESA's satellite (to practice maneuvers) and then said "no, we won't move it back out the way".

No. All deorbiting objects (“satellites” or debris, whatever you want to call them) are going to pass through the orbit of the ESA satellite which is intentionally in a very low orbit. It is the ESA that actively moved into that orbit by design, intention and active navigation. SpaceX intended their satellite to lift to a higher orbit but it couldn’t make it, so it is being deorbited by atmospheric drag. All orbits a…

That article started that the Spacelink satellite -had- been at a much higher orbit (the "regular" for their satellites, but had been brought down "to test de-orbiting maneuvers". Do you have a source to the contrary?

Also, the ESA satellite has been in that orbit for 8+ years. It wasn't "moved" into the Spacelink orbit by any means.

I get that en route to or from orbit, entities will pass through other orbits.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#175

Post by manicdee »

FireBeyond wrote: post #174
manicdee wrote: post #150

Earlier quoted context omitted.

No. All deorbiting objects (“satellites” or debris, whatever you want to call them) are going to pass through the orbit of the ESA satellite which is intentionally in a very low orbit. It is the ESA that actively moved into that orbit by design, intention and active navigation. SpaceX intended their satellite to lift to a higher orbit but it couldn’t make it, so it is being deorbited by atmospheric drag. All orbits a…

That article started that the Spacelink satellite -had- been at a much higher orbit (the "regular" for their satellites, but had been brought down "to test de-orbiting maneuvers". Do you have a source to the contrary? Also, the ESA satellite has been in that orbit for 8+ years. It wasn't "moved" into the Spacelink orbit by any means. I get that en route to or from orbit, entities will pass through other orbits.

Deorbiting is exactly the process I was describing.

SpaceX did not deliberately move their craft to interfere with Aeolus. Aeolus is deliberately placed where every deorbiting craft will interfere with it. It’s like someone setting up an office in the foyer of an apartment complex. Everyone entering or leaving the complex is going to walk through the office. They aren’t deliberately walking through the office, it’s just that your office is where everyone is walking to get to where they are going.

In addition, SpaceX is testing deorbiting satellites with Hall effect thrusters that are barely powerful enough to raise orbit from higher in the atmosphere. At this altitude the thrusters would have little or no effect, so the craft is more or less an inert piece of space junk which SpaceX can possibly rotate using reaction wheels and magnetic torquers.

Words have meanings, and there is a vast semantic gulf between “SpaceX refused to take action” and “SpaceX were incapable of taking action”. The author used “refused” but published the article before investigating further. Expect a better story to come from the likes of Loren Grush in a couple of days once people have had time to get a response from SpaceX and digest just what is going on here (NB: ESA budget under review in November, as per ESA’s entire tweet thread of which this social media shitstorm is only responding to the first because it mentions SpaceX)

This is really just a semantic argument so I will leave it here. Reread the article but completely ignore the inflammatory clickbait title and any of the author’s own (emotive, inflammatory) words on the matter, stick to only the quotes from named sources and you should be golden.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#176

Post by manicdee »

HarryHirsch wrote: post #157
manicdee wrote: post #148

Earlier quoted context omitted.

The track record of experimental designs deliberately intended to push the boundaries of reliability really does not give us any idea of what to expect for the future.

Spacecraft engineering is inherently conservative because of reliability concerns, you can't take a tow truck and mechanic in orbit to fix things when it turns out that you didn't understand the latest technology quite as well as you thought. Space isn't the place to push technical boundaries, also because of orbital littering.

The inability to take a tow truck to orbit is exactly why you need to push the boundaries to find out what works and what doesn’t. Also note that “littering” is an irrelevant analogy in these orbits because of their low altitude. Atmospheric drag will cause anything in these orbits to deorbit in a matter of years to decades.

Just don’t go doing stupid stuff like releasing hundreds of millions of copper needles in a three-thousand-kilometre orbit as part of a misguided attempt to provide a reflective surface to carry military communications around the globe. That would be actual littering, as would any test of an anti-satellite weapon.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#177

Post by manicdee »

dahdum wrote: post #164
manicdee wrote: post #147

Earlier quoted context omitted.

The bigger issue is that ESA is coming up to an important administrative date in November where their future budget will be determined, and they want money for their automation program. So they have to portray space as dangerous, ESA processes as desperately in need of improvement, and this specific example of a super expensive research satellite coming close to part of a future megaconstellation makes for great atte…

SpaceX playing chicken with cheap disposable Starlinks against multibillion euro public satellites does make space dangerous.

Nobody is playing chicken here.

The SpaceX satellite is for all intents and purposes inert, since it is incapable of significantly adjusting its orbit.

You know the old joke about the US Navy warship giving way to the second class seaman, right?

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#178

Post by manicdee »

dahdum wrote: post #163
manicdee wrote: post #145

Earlier quoted context omitted.

The “more to it” is that ESA is gearing up to request funding for their AI project, billed as an automated tracking and avoidance manoeuvre planning system capable of handling the vast numbers of objects and debris expected to be in orbit in the near future. This was not about “SpaceX refused to move” but “we need money to build this automated system so we don’t have to do it all by hand,” and an additional level whi…

> The last thing this is about is SpaceX being “arrogant” or “refusing to move a satellite.” SpaceX entering ESA’s orbit and arrogantly refusing to move is an excellent showcase of the need for better avoidance systems, especially since they plan to launch 12k of them. It’s also an excellent warning of SpaceX’s ethical framework.

It’s more likely to be an excellent example of why we should always wait two days to find out the real story.

Clickbait headlines are poison, as are hearsay and anonymous sources using emotive language like “SpaceX refused” to move their satellite.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#179

Post by manicdee »

elkos wrote: post #151
dahdum wrote: post #146

Earlier quoted context omitted.

Have they stated anywhere they lost control of their satellite, that it was inert? It was under power and reportedly performing a test maneuver. If they didn’t have control over it they could have easily stated as such to ESA and avoided any bad PR at all, or even just in response to this story.

That wasn't inert on the contrary. https://twitter.com/planet4589/status/1168637324592328705?s=...

I apologise for using the word inert when the satellite was merely incapable of manoeuvring as required in the timeframe allowed.

Re: SpaceX Refused to Move Satellite at Risk of Collision with a European Satellite

#180

Post by manicdee »

dahdum wrote: post #146
manicdee wrote: post #143

Earlier quoted context omitted.

Can you describe what action SpaceX should have taken to prevent their inert space debris from potentially colliding with someone else’s active satellite?

Have they stated anywhere they lost control of their satellite, that it was inert? It was under power and reportedly performing a test maneuver. If they didn’t have control over it they could have easily stated as such to ESA and avoided any bad PR at all, or even just in response to this story.

You will note that the official ESA comments on the matter are that “nobody did anything wrong,” and (to paraphrase) “we need better technology to remove humans, email and phone calls from the loop”.

For all you know, SpaceX did state to the ESA that their satellite was incapable of performing the required course adjustment. Something along the lines of “our satellite is incapable of adjusting its orbit to accomodate your request.”

As for the author publishing the story before receiving a response from SpaceX, that’s on the author not SpaceX.

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