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No, it takes a lot of energy to get out of orbit. But unless the satellite is in a few very special locations in Earth's orbit, its orbit will naturally decay o
by anchpop 6y ago
No, it takes a lot of energy to get out of orbit. But unless the satellite is in a few very special locations in Earth's orbit, its orbit will naturally decay over time and eventually fall back to Earth, usually burning up in the atmosphere. (Above low-earth orbit this could take a very long time, but now satellites are required to be designed with deorbiting in mind)
Often some parts of the sat still make it to the ground, but SpaceX's Starlink sats for example are designed to fully burn up in-atmosphere within a year of deorbiting.
- throwaway-8c93 6y ago> No, it takes a lot of energy to get out of orbit Does it? It takes ~10000 m/s of delta-v to reach low Earth orbit, but afaik only about extra ~30 m/s to deorbit, with aerobraking taking care of the rest of the velocity. Or is there any extra intricacy in the details?
- cyphar 6y agoThey were talking about escaping orbit (reaching escape velocity which is ~41% higher than the orbital velocity and requires getting more fuel into orbit), not degrading the orbit so that the satellite burns up in the atmosphere. As the article discusses, the latter has the flaw of putting alumina particles in the upper atmosphere which remain there for many years.
- jvzr 6y agoI'm pretty sure parent meant "escape Earth's orbit", not "deorbit"
- Symmetry 6y agoOrbital decay depends on a satellite's particular orbital height to a huge extent. A satellite orbiting 250 km up might come down in a week. The same one at 500 km might take centuries.