Would it be possible to put a satellite into the same orbit as the Moon, but far enough ahead or behind the Moon to remain in place?
Has this ever been done in practice?
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Sign up to join this communityWould it be possible to put a satellite into the same orbit as the Moon, but far enough ahead or behind the Moon to remain in place?
Has this ever been done in practice?
Yes. Trojan orbits (60° before or after the Moon) are even stable in most cases. These points are called the L₄ and L₅ points, which are two of the five Lagrangian points.
These orbits are mostly impractical (nothing is there).
Today the most known is the Chinese Queqiao satellite, which is a communication relay to their probe on the far side of the Moon. Instead of using L₄ or L₅, Queqiao is in a halo orbit around another Lagrangian point; Earth-Moon L₂.
Has this ever been done in practice?
Not intentionally, and not by humankind. But by nature, the answer is yes. Thousands of objects are known to co-orbit with Jupiter about the Sun-Jupiter L4 and L5 points, millions are thought to exist. Trojans (the generic name for small objects that co-orbit with a somewhat large object about an even larger object, with the small objects in pseudo orbits about the triangular Lagrange points) are known to exist for Neptune, Mars, Uranus, and Earth. Two of Saturn's moons, Tethys and Dione, have trojans in pseudo orbits about their triangular Lagrange points.
One limitation of using L4 or L5 is, ironically, their natural stability. They are now known to attract dust clouds. Putting and station-keeping a satellite at the ostensibly unstable Lagrange points avoids having to deal with a higher dust density. In additiin, L1 and L2 offers a closer view of the Moon.