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Space junk debate aside, many large satellite companies (and governments too) are responsible for a large number of both operational and defunct sats that are still in orbit. When other companies or space agencies talk about cleaning up space, they often mention "pushing" defunct sats into the atmosphere where they will burn up.

How do the companies that own these sats feel about this? Would they ever want their non-operational tech salvaged instead of burnt up in the atmosphere?

How big of a satellite could theoretically be "pushed" into the atmosphere? Could they not completely re-enter like the Chinese Long March 5B booster?

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  • $\begingroup$ Mir was a pretty big satellite... en.wikipedia.org/wiki/Deorbit_of_Mir $\endgroup$ Jun 15 at 19:19
  • $\begingroup$ If you told the "responsible" party that for USD9.95 you would deliver their satellite, in as-found condition and neatly wrapped, to the address of their choosing then they might well want to analyze how the various materials stood up to the rigors of space travel. Or not want to deal with any hazardous materials, e.g. propellants. Or put it in a museum after suitable preparation. Whether they "want" them back at a higher price may have a different answer. $\endgroup$
    – HABO
    Jun 16 at 2:55
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    $\begingroup$ Snatching a competitor's satellite and bringing it back to Earth could tell a lot. What sensors / effectors / spy equipment / avionics / software are they using? Are they better or worse than us? While companies / countries may not want their decrepit satellites back, competitors would love to get their hands on one. $\endgroup$ Jun 16 at 4:47
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    $\begingroup$ @David Hammen, if such country is a signatory of the Outer Space Treaty, cf Art VIII, its reputation is at stake. If it has the unique technology edge to perform such a challenging and costly operation (like the US were, in the Shuttle era), it is doubtful what it can learn from such operation. If there is a technologically closing in competitor, the tempted state should be also worried that said competitor "return the courtesy". "Snatching a competitor satellite" is legally, politically, technically, and even commercially, a non-starter. $\endgroup$
    – Ng Ph
    Jun 16 at 12:19
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    $\begingroup$ @NgPh, But we do have this... Just in case... $\endgroup$ Jun 16 at 17:23
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Getting a defunct satellite back is extremely more expensive than burning it into the atmosphere. A heatshield is necessary for reentry, parachutes to slow down and small rockets to slow down just before hitting the ground. An attitude control to avoid a reentry with parachute container first. Mortars are needed to reliable eject the chutes. A sequencer to control all steps at the right time and height.

All these extra equipment is very expensive, but to lift all that into an orbit before needs even much more money.

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  • $\begingroup$ Exactly. I would add that most commercial satellites are mass-produced, making it cheaper to just send up another. It's the unique (e.g. Hubble) and military satellites that are worth repairing or retrieving. $\endgroup$
    – DrSheldon
    Jun 16 at 4:39
  • $\begingroup$ @DrSheldon that's probably true for LEO, since quantitatively speaking most commercial satellites in LEO are Starlink satellites. But in GEO I think they are still built pretty-much one at a time to order, or occasionally two in parallel perhaps. $\endgroup$
    – uhoh
    Jun 16 at 6:51
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    $\begingroup$ @uhoh, correct that GEO are "hand-made". But also, retrieving a GEO is not feasible with current state of technology (re-fuelling, or reparing, perhaps years from now). That's why GEO are sent to a higher "graveyard" orbit. $\endgroup$
    – Ng Ph
    Jun 16 at 12:29
  • $\begingroup$ Wrong comparison: retrieval cost is >> cost of a new one, including launch. $\endgroup$ Jun 16 at 15:31
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The 1st part of your question

How do the companies that own these sats feel about this? Would they ever want their non-operational tech salvaged instead of burnt up in the atmosphere?

seems to imply that, after a company has lost control of a space object (dead satellites, rocket boosters,...) they are still entitled to claim ownership (because they paid for it). The answer is no, they can't. It is the state that registered the objects that has ownership of the object (well, if that state is a signatory or party of the Outer Space Treaty, Art VIII). Same goes for the counterpart, the liabilities (same reference, Art VII).

For the 2nd part of your question, you should know that the atmosphere extends very far into outer space Wiki. Satellites high-up to about 600Km can still "feel" the drag effect of atmospheric particles, thus reducing their lifetime. Without a repetitive altitude keeping engine, they inevitably fall back (and usually burn before they crash). Below ~350Km, they fall back fairly quickly (years if not months). Above ~700 Km they can continue to orbit for centuries. The bottom line is that although the size of the object plays a role in the drag, it is really the orbit height that is determining. So, "pushing an object into the atmosphere" means lower its orbit until the drag effect is strong enough to bring it down (hopefully quickly). This is why most launching states ask that satellite companies keep enough fuel at end-of-life to have a controlled re-entry (for low orbits) or to boost into higher orbits (for GEO).

For the Chinese booster (and other junks belonging to the US,Russia, France, ... as part of their expendable launches, and by -bad- design or by accident can't have controlled-reentry), had it not crash in the high seas, but say in Australia, what would happen on the legal side? If the crash creates damages to Australians lives and properties, it is the Chinese government who is liable (even if the booster belongs to a private company, say SinoX). If it doesn't, Australia MUST return all the debris to China, as per the Outer Space Treaty.

You may ask, if there is a dispute, say on the indemnifications, which tribunal has jurisdiction and can it enforce its decision? This is where the bat hurts ... the Treaty is silent on that.

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How do the companies that own these sats feel about this? Would they ever want their non-operational tech salvaged instead of burnt up in the atmosphere?

I have a different take on aspects of this than some of the other answers.

While probably a qualified "no", in that they usually wouldn't necessarily want to pay for a salvage mission for the purposes of salvage per se, if the mission plan was to bring it back to Earth and auction to the highest bidder on E-bay, the original owners (or perhaps even governments) might give some thought to bidding competitively, or taking legal action in order to attempt to block the sale or impound the recovered satellite.

A lot of work has gone into developing and perfecting technologies of some satellites. There may be certain know-how, trade secrets or even military secrets to be gleaned from the spacecraft, as well as bits and pieces that might fall under ITAR (just for example, GPS receivers that work at orbital altitudes and speeds).

From my profoundly prescient and unnecessarily down-voted answer:

and this just happened:

Here's a video of Patrick Lucas Austin, Time Technology Columnist interviewing Gwynne Shotwell, president and chief operating officer of SpaceX just a few weeks earlier, cued at 03:33

Q: In a more literal sense, Space is littered with a lot of dead things you know, I’m talking space debris. Is SpaceX considering any new technology or even new policy to combat…

A: In fact the Starlink program was a great opportunity to have a pretty big voice in that and also learn our own lessons1... as you mentioned there’s rocket bodies littering the space environment and dead satellites littering the space environment... And I do want to put in a plug for Starship here. Starship is an extraordinary new vehicle capability. Not only will it decrease the cost of access to space... but it also has the capability of taking cargo and crew at the same time, so it’s quite possible that we could leverage Starship to go to some of these dead rocket bodies (other people’s rockets of course!) basically go pick up some of this junk in outer space. (emphasis added)

1cf. https://astronomy.stackexchange.com/q/34219/7982 (based on a Shotwell quote)


The video Engineering Today video SpaceX Starship could be used to clean up Space Debris discusses the failed (EOM), large, ESA satellite Envisat (also here).


From Ashwati Das's spacegeneration interview of Shotwell:

A: If we were to have a satellite that was going to be troublesome, what I would love to do is think about using the Starship capability to go pick up the space debris. And I know that that’s really hard and it’s very much kind-of a futuristic concept, but I definitely think that that’s something worth pursuing. So we wouldn’t service the satellite, but it would be great to go up and “grab it” and bring it back.

cued at 08:37

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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage
    Jun 16 at 18:31
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Satellite technology has advanced so quickly that typically a satellite that's run out of fuel is completely outdated, it makes no financial or practical sense to try to recover them. So no, they don't want their satellites back, they'd rather them be de-orbited so they are no longer a liability.

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  • $\begingroup$ mostly correct, but the situation is a little bit subtle. Even an outdated satellite can be of value, mostly in orbits where available positions/frequencies are golden resources (eg GEO). Sometimes, a company runs out of time to activate its priority filing, according to the ITU process of "bringing into use". An end-of-life satellite that can be moved to the coveted position and that can transmit (even weakly) on the right frequencies can extend the priority grant. $\endgroup$
    – Ng Ph
    Jun 16 at 9:48
  • $\begingroup$ That's value in space @NgPh, not value back on earth which is the question. $\endgroup$
    – GdD
    Jun 16 at 10:06
  • $\begingroup$ Ok, if there is such a restriction in the question (which I don't think there should be). $\endgroup$
    – Ng Ph
    Jun 16 at 10:31

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