I’ve seen a lot of stuff from the CCPs state-run media and official diplomatic messages about this, but I haven’t seen a lot from other sources. Does anyone know what the straight dope is on this event? The Chinese are claiming they had to move their station to avoid…something…from StarLink. I don’t know if it was a single satellite (they are pretty small) or a cluster. I looked it up, and usually, StarLink constellations fly at a higher altitude than the Chinese space station (~350KM for the Chinese space station, ~550KM for StarLink constellations), but I also know that StarLink does initial injection orbit lower, then moves the satellite constellations up to their final orbits over time. I didn’t think StarLink would put them in a potential orbit that could interfere with a manned station of known orbit, however. So, wondering if anyone knows what happened (and, preferably, not from a Chinese source).
It’s difficult to find anything from non-Chinese sources on this since the Chinese have been very vocal about it and pretty much all media have been quoring them. But from the formal complaint (pdf) that they have lodges with the UN, it seems the issue is the following: The two satellites in question were Starlink-1095, launched in January 2020, and Starlink-2305, launched in March 2021. China claims that between March and June, 1095 went down from its initial altitude of 555 to 382 km (which seems to be true), and that this is where the near-miss incident occurred on 1 July. I couldn’t find out why it did that, possibly it had simply reached the end of its life and its orbit was decaying (it subsequently re-entered in September).
2305 had been more recently launched, and it seems that during the time in question it was gradually rising from an altitude of about 350 km to its final 550 km (link). The near-miss supposedly occurred on 21 October, when it was around 390 km.
Looks to me as if, at least from publicly available altitude data, the story the Chinese published is not plainly implausible.
No, I don’t think it’s implausible, I just wasn’t seeing anything from non-Chinese sources. Thanks for the info…appreciate it. The first instance I could see for sure…I know that the StarLink satellites have the ability to deorbit themselves if they are having issues or just EOL, so that seems like it could be what happened here. The second one also seems plausible, since that is how they operate, with a lower orbit injection, then they spread out and slowly move into their final orbits. Not sure why StarLink didn’t seemingly plan things out to avoid even a close pass of a manned station, but I could see it as happening since they are putting up so many of the things.
Yeah, this is what has been repeated. Note, ‘China has informed…’…what I’m trying to get is a non-Chinese (really, a non-CCP) source on this stuff to gauge what actually happened, as opposed to what the CCP is saying happened. This isn’t to say that the CCP and their state-run media reports are lies, just that I’d like a different source, as they aren’t all that reliable wrt such statements.
Because Elon Musk is about as trustworthy as you think China is?
Don’t forget that, true or not, China has a vested interest in denigrating and possibly stopping the deployment of a service that can be used to connect directly to the internet regardless of national boundaries, that uses small equipment that can be carried in as luggage. Whatever they can say to discourage such services presumably they will take the opportunity.
Exactly. They are planning their own version of StarLink, so that’s one good reason they have in either exaggeration or fabrication. Or, it could have happened, and they are making a bigger stink about it to draw attention. At any rate, I’m just trying to get a non-CCP state-run media take on it to check the facts.
Read the damn article.
Satellite tracker Jonathan McDowell, of the Harvard-Smithsonian Center for Astrophysics, confirmed the two close approaches and avoidance burns using data published by U.S. space tracking. The October pass appears to have been within three kilometers.
The note from China requested the UN secretary-general to remind others that, “States Parties to the Treaty shall bear international responsibility for national activities in outer space, including the moon and other celestial bodies, whether such activities are carried on by governmental agencies or by non-governmental entities, and for assuring that national activities are carried out in conformity with the provisions set forth in the present Treaty.”
McDowell told SpaceNews via email that the “A/AC.105 UN series is usually ‘we did this, watch out,’ not ‘we are unhappy someone else did this,’ making this complaint very unusual.
“I expect people will go ‘um, you know the ISS had to dodge debris from the Chinese ASAT more than once too?’ But I think this is another sign we are in a qualitatively new era where the crowding of low Earth orbit is concerned,” McDowell noted.
Ok, I missed the first paragraph. Sorry about that. That is what I was looking for, at least to answer part of what I’m asking…an independent source for tracking. Thank you.
I think the final two paragraphs you quote there also tell the tale.
This might be something as minor as differing tolerances of margin of error. 3 km is a pretty long distance: It could be that SpaceX is sufficiently confident in their orbital parameters that they consider a 3 km flyby to be well within safe parameters. But if the Chinese didn’t consider it safe, they might maneuver to miss by a larger distance.
And, of course, what distance is regarded as “safe” can be influenced by political factors.
This website has a forecast tool for “close conjunctions” between Starlink satellites, at it also gives the predicted closest distance between the two objects. They define such a close conjunction as having a distance of less than a kilometre between the objects. Such events seem to happen routinely, there’s three of them listed for the next 24 hours, the narrowest “near miss” of those being at 557 metres. That’s only of Starlink satellites among each other, and only predicted incidents. If SpaceX is comfortable having its own satellites pass each other that closely, then they might probably have a similar risk tolerance between one of theirs and someone else’s spacecraft.
Try this: 
https://celestrak.com/SOCRATES/
Definitely a good point, especially with the info Schnitte provided. Risk is relative and how you calculate it is going to differ, especially as there is no standard among the various powers and now companies who are putting stuff in orbit.
This was my thought as well. When I heard this story and how strongly the CCP and their state-run media were criticizing SpaceX and StarLink I was thinking of the fairly recent Russian destruction of a satellite and the well-publicized lashing they gave the Russians over the incident. I was thinking that I bet the CCP saw that and thought…man, that seemed to work, we should try that too! This would have been a perfect incident for them to do so since it not only will perhaps carve out their own expectations for risk going forward (risk to others…they don’t seem to care much when it’s their stuff that causes issues) as well as a slam on StarLink as a competitor to their own plans to put up a similar constellation of satellites.
That also leads into questions about who is responsible for avoidance in situations like this. One might start with the expectation that between a space station and a small satellite, it should be the satellite that maneuvers to avoid the collision. But what if the operators of the station demand a larger miss distance? And is there any agreement about what is reasonable vs. not?
It’s somewhat reasonable that a manned station might want a larger distance, say 5 km vs. 1 km. But perhaps they should be the ones to pay that cost (via propellant) since it is their station at risk. Or, even if there is general agreement to give manned stations a larger berth, one can imagine an owner (either for real reasons or political ones) demanding an unreasonably large distance, say 10 or 100 km. In that case it should be entirely upon them to maneuver out of the way.
All these questions and more (such as finding out if the original claims are even real) certainly point to the need for an international group to monitor space objects and manage potential collisions. Starlink is just the first of many constellations to highlight the current lack of a coherent system. It’s only going to get worse until something is set up.
Does the treaty include a version of squatters’ rights? IIRC, Starlink satellites are launched in a low-ish orbit and slowly maneuver their way up to their designated higher orbits using very low power thrusters - and the obsolete or dysfunctional ones should maneuver themselves down to destructive re-entry. Presumably a satellite in the process changing orbits is obliged to avoid others already in stable orbits, and none should be inserted into a stable orbit that conflicts with an existing satellite?.
It’s also plausible that the Chinese did technically believe the distance to be safe but took the opportunity to enact a theatrical maneuver in order to provide a basis for a political complaint. This starts to become necessarily speculative as to motive, but it wouldn’t be the first time a government has performatively flinched at something because it served some larger purpose.
Yes, that’s basically what I meant when I said that “what distance is considered safe could be influenced by political factors”.
ISS manouvered when debris was appraching to within 1.8km.
and in 2015, they manourvered ISS because of debris that was going to only as close as 3 miles.
and
https://blogs.nasa.gov/spacestation/2015/06/08/controllers-steer-station-clear-of-space-debris/
But they were out of control items causing the collision risk.
It seems to me to be unavoidable … spaceX had to take the risk of launching into a close approach orbit… The predicted orbit from the launch has a wide error , and so once they get it into orbit they measure that orbit up more accurately… and they can adjust it if there is a collision in the current orbit…
So I think china is overreacting, and are purposefully playing the same line they would use for out of control Debris,but in this case its for fully in control launch… and all measurements have error margins. the starlink data would be very accurate and they could ensure it was so by steering the starlink satellites to be on the course accurately.
Debris has a more easily predicted path than something still being maneuvered into position. So based on that, and your cites, I’d say they behaved reasonably.
If it had been any other country than china we wouldn’t be trying to find nefarious motives, we’d just take it at face value.