Communication satellites orbit at an altitude a couple of hundred times above the satellite that the Indian government recently shot down. Also GPS-satellites are about one hundred times further up than this target was.

Does the large distance to satellites in GEO and GPS orbits allow for them to use propulsion to evade an incoming projectile? I suppose it is possible, but how feasible and costly would it be to design satellites with such a feature? Perhaps shutting down radio emissions and turning Solar panels edge on to limit its visibility and minimizing its target area, while boosting away in some random pattern. Then resuming normal operations. Some ballistic missiles under development intended for ground (naval) targets make maneuvers during their final fast approach to avoid air defense fire. Could something similar be used to protect satellites?


You need 2 items to evade a missile:

  1. a means of detecting an incoming missile. There are specialized satellites that are used to monitor ICBM launches, IDK how well the technology scales down.
  2. enough maneuvering capability to evade a missile - while the missile is maneuvering to follow you. ASAT missiles can already maneuver to make sure they hit their target. A satellite will be much larger than the missile, so you need more propellant and a bigger engine to outmaneuver the missile. Thanks to the tyranny of the rocket equation, this adds up quickly.
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  • $\begingroup$ The question asks about a "projectile" which sounds passive to me, like a bullet or a shell. You've answered about an ICPM or guided missile, so I think you haven't quite addressed the OP's question as asked. $\endgroup$ – uhoh Apr 1 '19 at 0:46
  • $\begingroup$ Also, I think the better question is how high can current anti-sattelite missles reach. The rocket equation applies to them as well. $\endgroup$ – Knudsen Number Apr 1 '19 at 5:43
  • $\begingroup$ ASATs are never passive bullets, so I'm not going to address that hypothetical scenario. $\endgroup$ – Hobbes Apr 1 '19 at 8:07
  • $\begingroup$ Isn't that the whole point of the question though? It is a lot harder to use anti-satellite missiles on a GEO satellite than it is on a LEO satellite. Can an anti-satellite missile even have powered ascent all the way up to GEO? The US RIM-161 only has a range of 2500 Km, so I don't think it even could make it to GEO at 35,700 Km altitude. $\endgroup$ – Knudsen Number Apr 9 '19 at 22:18
  • $\begingroup$ I also don't think you need to scale down the missile detection system to place it on a satellite. You could just radio the satellite the position of the missile from the ground. $\endgroup$ – Knudsen Number Apr 9 '19 at 22:21

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