Maybe this should be in Nostupidquestions as I’m aware the moon exists. And I guess there may be an orbit zone where things tend to remain in orbit. But curious…
The full context question is: For man-made satellites, would they benefit by having a “Self destruct” button?
Sure it may add more debris but since an explosion would scatter debris in all directions, anything flung up or down would cause it to get out of this geostationary zone/band… And hopefully come crashing down to Earth, reducing overall debris? Compared to an abandoned satellite, remaining in orbit and breaking down due to relatively low energy collisions with surrounding debris.
Basically I’m trying to justify self destruct buttons. Thank you!
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All orbits require very minimal maintenance, the closer to earth, the more maintenance required . Far enough out, and its basically maintence free, except for avoiding other debris.
The problem with an explosive self destruct is that not all debris will go down into lower orbits, some with go higher and therefore take even longer to deorbit. Its also a lot easier to track one dead satellite instead of thousands of minute particles.
And ideal “self-destruct button” would actually be a thruster firing in the direction of travel, which would slow it down and drag it into the earth, or if facing the other way, boost it up to a “graveyard” orbit. Both these exist on many satellites already.
Wont you eventually leave orbit if you are too far away?
As an addendum to this comment:
The moon is also a source of orbital pull and does affect everything on the inside of its orbit and is probably the most significant source of disturbance at geostationary distances.Thank you for your response!
Pardon my crappy drawing and simplification… trying to understand…
- So Zone 1 requires a lot of maintenance energy
- Zone 2 may be maintenance free zone
- Zone 3 may require more energy than Zone 2 but less than Zone 1
- And finally Zone 4 will be even less energy to stay in orbit but needs more energy to stay in line due to increased travel distance
Is that right?
But yes, there goes my self destruct notion down the drain.
There is no orbit altitude that requires more energy to maintain than a lower altitude.
Zone 1 requires more reboosting that 2, which requires more than 3, which requires more than 4. I dont know the exact relationship, (someone else might know), but we can consider it linear for simplification. The further away from earth, there will be less atmospheric drag, which means a longer stable orbit.
The travel distance doesn’t really change anything, it doesn’t affect the orbit stability.
Think of it like this spring. Your satellite can start at any point, and with no additional energy, Itll follow the path all the way down to the middle (earth). Start low, and itll reach ground quickly, start high, and itll take a lot longer. There is no energy required to stay on the spiral path. Once the sat is low enough, you may want to reboost, which is when you need to use energy to jump up to a higher point on the spiral, at which the path continues.
Sorry to disappoint, but exploding something at GEO would make things worse.
All satellites in orbit of Earth will experience atmospheric drag. Even the Moon is bumping into gas atoms.
Geostationary satellites will eventually fall. It might take millions of years, but eventually the thin atmosphere will slow those satellites down enough that their orbit will fall into the thick, lower atmosphere where they’ll burn up or crash into the Earth’s surface.
Exploding a satellite up there will just make a shotgun spray of projectiles that will still take millions of years to fall. Assuming the projectiles shoot off in all directions fairly evenly, then the ones that get shot backwards relative to the motion of the satellite will end up in a lower orbit that will decay faster. The pieces that get shot forward might actually escape Earth orbit all together and become little asteroids orbiting the Sun.
The thing that’s special about geostationary orbit isn’t that the orbit of things at that altitude does not decay. That altitude is special because at that altitude, orbital speed is equal to the Earth’s rotational speed. A satellite at that altitude over the equator will remain over that same longitude - it won’t rise and set like the Moon, it will remain in the same spot overhead both night and day.
Most modern GEO sats actually have dedicated end-of-life fuel reserves specifically to boost themselves into that “graveyard orbit” about 300km higher than GEO, where they’ll stay for basically eternity without interfering with active satellites.
