4 ms·
Why L2 and not L1? Isn't L1 supposed to be more stable?
by acobster 8y ago
Why L2 and not L1? Isn't L1 supposed to be more stable?
- TomK32 8y agoI think it's about communicating with the space nazis living on the far side of our moon...
- evgen 8y agoI would guess the reason is that while L1 is not stable it is still easy to maintain with minimal thrust and the instability of the point means that things 'passing through' do not need to work hard to leave the orbit. The unstable Lagrange points are not places that will collect unpowered/unguided objects or debris but they provide easy station-keeping opportunities.
- tqkxzugoaupvwqr 8y agoI can only speculate, but the article alludes to establishing permanent communication with the moon’s backside: > A satellite or spacecraft in a halo orbit [around L2] can be constantly in Earth’s sight and can therefore maintain communication between astronauts on the far side of the moon and control rooms back home.
- greglindahl 8y agoChina currently has a relay satellite at the Earth-Moon L2 for exactly this reason, they're going to launch a mission to land on the back side of the moon.
- troymc 8y agoThe L1, L2 and L3 points are all unstable, but there are nearby orbits that are neutrally stable, e.g. the halo orbits and the orbits described in the article. A spacecraft on one of those orbits will still need to use some propellant to get it back on track from time to time (for "station keeping"), but it's typically not very much propellant. Such orbits have already been used for other missions, such as the Solar and Heliospheric Observatory (SOHO).