I'm taking discarded here to be non operational spacecraft in free space not on any planetary body. Well - Snoopy is pretty large but not the largest. One of the most interesting large ones. The ascent stage for the Apollo 10 lunar lander - the one before Apollo 11. They rehearsed everything, all the way to the lunar landing except they didn't land.
All the other ascent stages were discarded to impact into the Moon or into Earth (Apollo 13). But this one was sent on a trajectory that would send it into an independent orbit around the Sun.
This means it is almost certainly still out there, on an independent orbit around the sun and could in principle be recovered. It's the only "once human occupied" spacecraft from the Apollo era still in free space.
The Mission to Find the Missing Lunar Module
Then, there are lots of satellites in the Graveyard orbit for geostationary satellites at the end of their operational life, about 300 km above the normal orbit. See also Where Do Satellites Go To Die?
Other satellites are in orbits high enough to not fall back to Earth for centuries. One of the larger ones is Envisat.
It is a problem for space debris because it's at an altitude of only 772-774 km and if it was hit by some other debris it might break up into hundreds of pieces and so start a chain reaction with other satellites eventually breaking up also.
It's a top priority as a satellite to de-orbit to demonstrate the technology for cleaning up Low Earth Orbit of space debris.
Then - there are
See also List of artificial objects in heliocentric orbit
Most of the ones that are in the inner solar system will probably hit one of the planets, the sun, or Jupiter, or be ejected from our solar system some time in the next twenty million years - because Earth and the other terrestrial planets, assisted by Jupiter, are effective at "clearing their neighbourhood" on that timescale. That is, assuming they are not recovered by future humans and put into museums or what not.
All the other ascent stages were discarded to impact into the Moon or into Earth (Apollo 13). But this one was sent on a trajectory that would send it into an independent orbit around the Sun.
This means it is almost certainly still out there, on an independent orbit around the sun and could in principle be recovered. It's the only "once human occupied" spacecraft from the Apollo era still in free space.
Then, there are lots of satellites in the Graveyard orbit for geostationary satellites at the end of their operational life, about 300 km above the normal orbit. See also Where Do Satellites Go To Die?
Other satellites are in orbits high enough to not fall back to Earth for centuries. One of the larger ones is Envisat.
26 m (85 ft) × 10 m (33 ft) × 5 m (16 ft)
- far larger than Hubble which is 13.2 m × 4.2 m (43 ft × 14 ft)
It is a problem for space debris because it's at an altitude of only 772-774 km and if it was hit by some other debris it might break up into hundreds of pieces and so start a chain reaction with other satellites eventually breaking up also.
It's a top priority as a satellite to de-orbit to demonstrate the technology for cleaning up Low Earth Orbit of space debris.
Then - there are
- Third stages for many of the interplanetary missions.
Nearly all the missions to Mars, except MOMA, for instance, sent third stages also on a trajectory towards Mars, biased to miss it for planetary protection reasons - so they are orbiting in interplanetary space. Same is true for almost all the robotic missions that venture beyond the Earth and Moon. As well as some of the missions to the Moon. - Some spacecraft that missed their targets, failed to get into a capture orbit.
- Flyby missions to Mars etc.
- Orbiters that will eventually fall down to the planet but only many decades into the future.
See also List of artificial objects in heliocentric orbit
Most of the ones that are in the inner solar system will probably hit one of the planets, the sun, or Jupiter, or be ejected from our solar system some time in the next twenty million years - because Earth and the other terrestrial planets, assisted by Jupiter, are effective at "clearing their neighbourhood" on that timescale. That is, assuming they are not recovered by future humans and put into museums or what not.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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