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This is hardly a 'first'. ESA felt their satellite was being obstructed by SpaceX who moved into the space much later and didn't act responsibly as they should

This is hardly a 'first'. ESA felt their satellite was being obstructed by SpaceX who moved into the space much later and didn't act responsibly as they should have. So ESA decided to send out a press release.

ovi256 7y ago
Yeah, you can feel the bad blood behind the press release. Basically ESA nicely asked SpaceX to maneuver their sat and shorten its lifetime - they don't have a legal basis or enforcement mechanism anyway. SpaceX pretended not to hear until it was too late and ESA went ahead with their contingency plan of burning their own sat's fuel and lifetime instead.
- russdill 7y ago
  If it was really about burning fuel, ESA would not have waited until half an orbit before. The longer you wait, the more you have to burn.
  - tehbeard 7y ago
    Not really. a. They did an altitude increase. There's no real gains from an earlier burn that one might get when doing something like a hohmann transfer. b. Half an orbit before out means more/better telemetry to work with. c. They are from a quick google, well within the range where atmospheric drag plays a role, and you need to do station keeping. leaving it this late means you don't "waste" fuel from drag. Admittedly, my only credentials for this are a few thousand hours in KSP and reading around the subject. Anyone with a proper degree on this is welcome to correct me.
    - russdill 7y ago
      In that case they were simply adjusting their station keeping schedule and minimum (if any) fuel would be wasted. If that wasn't the case, they could raise or lower the altitude slightly several orbits before the "event" causing them to arrive at the intersection point earlier or later. For a desired time delta, the sooner your perform your altitude change the smaller the changed required.
  - october_sky 7y ago
    Sure, but I'm positive the ESA's argument is their fuel burn should have been zero.
- JshWright 7y ago
  I haven't seen any mention of ESA "nicely asking" SpaceX to maneuver. Is that referenced in another article?
- zaarn 7y ago
  The sat in question was in deorbit testing, it's lifetime was already short.
- blauekapelle 7y ago
  ESA said they didn't ask spacex to move their sat, they just said they let them know. Spacex replied they had no intention to move their sat, since it was in deorbit testing.
simion314 7y ago
Yeah, but ESA message is clear that space needs some regulation, now there is no rule who should do the avoidance, with more and more satellites you need some defined rules and coordination on handling this incidents. Also I am wondering if some cheap satellite destroys a expensive scientific one is there a law that could apply for recovering some damages and act as a incentive to prevent such a thing?
- gmueckl 7y ago
  As far as I know, everything that is sent into space is the responsibility of the nation that launched it and governed by its laws. So if two satellites were owned by organizations from the same country, that country's legal system would have to deal with the damages. I am not sure if the space treaties actually cover the case where multiple nations are involved. I wouldn't bet on it.
  - ceejayoz 7y ago
    > I am not sure if the space treaties actually cover the case where multiple nations are involved. I wouldn't bet on it. I would. https://en.wikipedia.org/wiki/Space_Liability_Convention https://en.wikipedia.org/wiki/Space_Liability_Convention > States (countries) bear international responsibility for all space objects that are launched within their territory. This means that regardless of who launches the space object, if it was launched from State A's territory, or from State A's facility, or if State A caused the launch to happen, then State A is fully liable for damages that result from that space object.
    - simion314 7y ago
      So for cars we have clear rules like on intersection who has the priority, on an incline, etc . It seems that in this case there are no rules, the SpaceX was following the rules but ESA thinks it was to risky or SpaceX are incompetent and could not do anything and couldn't even produce a response in time.
      - 7y ago
manicdee 7y ago
ESA felt no such thing. What you are recalling here is Jonathan O’Calaghan’s opinion that whoever was in an orbit first automatically has right of way. ESA’s take on the matter is that it was annoying that they couldn’t contact SpaceX, and that relying on email and phone calls between humans is not going to work when there are tens of thousands of satellites in orbit. The Twitter thread which started this was about ESA’s plans to automate their entire collision detection and avoidance process, and a call for an industry consensus on processes and protocols for communicating facts and intentions between satellite operators, and a set of rules and policies for managing space traffic, similar to what is done for international air traffic today.

ovi256 7y ago

Yeah, you can feel the bad blood behind the press release. Basically ESA nicely asked SpaceX to maneuver their sat and shorten its lifetime - they don't have a legal basis or enforcement mechanism anyway. SpaceX pretended not to hear until it was too late and ESA went ahead with their contingency plan of burning their own sat's fuel and lifetime instead.

russdill 7y ago
If it was really about burning fuel, ESA would not have waited until half an orbit before. The longer you wait, the more you have to burn.
- tehbeard 7y ago
  Not really. a. They did an altitude increase. There's no real gains from an earlier burn that one might get when doing something like a hohmann transfer. b. Half an orbit before out means more/better telemetry to work with. c. They are from a quick google, well within the range where atmospheric drag plays a role, and you need to do station keeping. leaving it this late means you don't "waste" fuel from drag. Admittedly, my only credentials for this are a few thousand hours in KSP and reading around the subject. Anyone with a proper degree on this is welcome to correct me.
  - russdill 7y ago
    In that case they were simply adjusting their station keeping schedule and minimum (if any) fuel would be wasted. If that wasn't the case, they could raise or lower the altitude slightly several orbits before the "event" causing them to arrive at the intersection point earlier or later. For a desired time delta, the sooner your perform your altitude change the smaller the changed required.
- october_sky 7y ago
  Sure, but I'm positive the ESA's argument is their fuel burn should have been zero.
JshWright 7y ago
I haven't seen any mention of ESA "nicely asking" SpaceX to maneuver. Is that referenced in another article?
zaarn 7y ago
The sat in question was in deorbit testing, it's lifetime was already short.
blauekapelle 7y ago
ESA said they didn't ask spacex to move their sat, they just said they let them know. Spacex replied they had no intention to move their sat, since it was in deorbit testing.

simion314 7y ago

Yeah, but ESA message is clear that space needs some regulation, now there is no rule who should do the avoidance, with more and more satellites you need some defined rules and coordination on handling this incidents. Also I am wondering if some cheap satellite destroys a expensive scientific one is there a law that could apply for recovering some damages and act as a incentive to prevent such a thing?

gmueckl 7y ago
As far as I know, everything that is sent into space is the responsibility of the nation that launched it and governed by its laws. So if two satellites were owned by organizations from the same country, that country's legal system would have to deal with the damages. I am not sure if the space treaties actually cover the case where multiple nations are involved. I wouldn't bet on it.
- ceejayoz 7y ago
  > I am not sure if the space treaties actually cover the case where multiple nations are involved. I wouldn't bet on it. I would. https://en.wikipedia.org/wiki/Space_Liability_Convention https://en.wikipedia.org/wiki/Space_Liability_Convention > States (countries) bear international responsibility for all space objects that are launched within their territory. This means that regardless of who launches the space object, if it was launched from State A's territory, or from State A's facility, or if State A caused the launch to happen, then State A is fully liable for damages that result from that space object.
  - simion314 7y ago
    So for cars we have clear rules like on intersection who has the priority, on an incline, etc . It seems that in this case there are no rules, the SpaceX was following the rules but ESA thinks it was to risky or SpaceX are incompetent and could not do anything and couldn't even produce a response in time.
    - 7y ago

manicdee 7y ago

ESA felt no such thing. What you are recalling here is Jonathan O’Calaghan’s opinion that whoever was in an orbit first automatically has right of way. ESA’s take on the matter is that it was annoying that they couldn’t contact SpaceX, and that relying on email and phone calls between humans is not going to work when there are tens of thousands of satellites in orbit. The Twitter thread which started this was about ESA’s plans to automate their entire collision detection and avoidance process, and a call for an industry consensus on processes and protocols for communicating facts and intentions between satellite operators, and a set of rules and policies for managing space traffic, similar to what is done for international air traffic today.