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This suggestion is complicated by the fact that you can't just boost out of an orbit with one short maneuver. You can turn your circular orbit into an elliptica
by fennecfoxen 7y ago
This suggestion is complicated by the fact that you can't just boost out of an orbit with one short maneuver. You can turn your circular orbit into an elliptical orbit, tangent to the original orbit; any debris in this orbit can still affect satellites in geosynchronous orbit when those satellites cross the point of intersection. Because the orbital period will be slightly longer than the original, and it is not tuned to any particular resonance, eventually all satellites in geosynchronous orbit will be at risk.
To actually get your satellite into a new orbit that doesn't intersect the original, you need to maneuver again: in this case, after you have followed the new (elliptical) orbit for ~12 hours (half an orbit) to its new high point.
All this is complicated by the fact that an explosion is further acceleration that shifts the orbit of the debris.
(That said, they appear to have ample time to move the satellite, it's a question of rules that would ordinarily prohibit it. The race is with the bureaucracy. Also, since the thrusters are designed for stationkeeping instead of propulsion, it's more of a gentle spiral outward than two fast maneuvers. Finally, some of the complication is about having ground tracking stations that can communicate with it: they have to speed it up by going lower, causing "eastward drift", before they can slow it down by going higher, which will give it westward velocity on the surface.)
- Floegipoky 7y agohttps://en.wikipedia.org/wiki/Hohmann_transfer_orbit https://en.wikipedia.org/wiki/Hohmann_transfer_orbit
- CydeWeys 7y agoWhat about it? That's not what this satellite would be doing.
- dcow 7y agoThis is exactly what fennecfoxen just explained as to why you can’t just use one long trust and leave it at that. It’s unclear whether they’re going to put the craft into a graveyard orbit (requiring this maneuver, sans a destination of “another orbital body”) or let it burn up, though (from the article at least).
- lisper 7y agoActually you can use one long thrust. What you can't do is use one short one. The Hohman transfer orbit assumes short high-thrust maneuvers because those are the most efficient. But if you are using long low-thrust maneuvers, as would be the case here, then one burn can suffice if it's long enough. (This is how, for example, ion engines work.) Source: I used to work for NASA.
- jfim 7y agoIs it because burning far away from the periapsis, it would change the altitude of the periapsis?
- lisper 7y agoYeah, pretty much, though the full story is a little bit more complicated than that. The reason a single short burn won't do it is that whenever you stop burning you will always be in an orbit that will return you to the point where you stopped (assuming you don't actually collide with the body you're orbiting of course). So you have to burn somewhere other than the orbit you want to get out of. The most efficient place to do that second burn is at apoapsis because that's where you get the greatest reduction in kinetic energy for a given delta-V (because that's where your velocity is the highest and so the force of burn is applied over a greater distance). But if all you have is a low-thrust engine (e.g. an ion drive) you can maneuver with long burns. The math gets hairier though.
- jfim 7y agoCool, thanks for the explanation. Looks like all that Kerbal Space Program was useful after all. :)
- outworlder 7y agoApparently there's plenty of fuel. How much Delta-V is there? Maybe enough for Earth escape velocity?