3 ms·

Can multiple spacecraft stay at the same Lagrange point? If not, what happens if two space agencies want to put something at the same point?

caymanjim 5y ago
Space is big and you don't need to be at the literal "point". There are already plenty of things sharing them.
nwiswell 5y ago
Sure. Being close to a Lagrange point doesn't mean you need _zero_ fuel, just a small amount. There's still the influence of the solar wind -- station keeping is inevitably necessary. As a result it doesn't really matter if a spacecraft is exactly at the Lagrange point or 100 km away from it, so there's no shortage of space. Also, this might be obvious, but it usually wouldn't make sense to park a spacecraft exactly at a Lagrange point because the spacecraft had to be moving in the first place in order to reach the Lagrange point. It would be a waste of fuel to slow down, so an orbit would typically be used instead.
- HPsquared 5y ago
  On the last part, does this mean it would orbit around the Lagrange point?
  - mkesper 5y ago
    That's exactly what e.g. JWST does: https://www.jwst.nasa.gov/content/about/orbit.html https://www.jwst.nasa.gov/content/about/orbit.html
kryptiskt 5y ago
Both Gaia and Webb are at the same Lagrange point, but in completely different orbits around it (Here is a visualization: https://www.universetoday.com/155022/esas-gaia-just-took-a-picture-of-l2-neighbor-jwst/ https://www.universetoday.com/155022/esas-gaia-just-took-a-p...). There is a smattering of solar observatories at L1 too.
jug 5y ago
The L2 orbit is just an orbit around Earth but pretty far way; you can be anywhere along that orbit. :) https://static.scientificamerican.com/sciam/assets/Image/2021/saw0122Gsci31_d.png https://static.scientificamerican.com/sciam/assets/Image/202...
noselasd 5y ago
There's a zone around of about 500000 miles where the spacecrafts can place themselves in orbit around these points, there's plenty of room

caymanjim 5y ago

Space is big and you don't need to be at the literal "point". There are already plenty of things sharing them.

nwiswell 5y ago

Sure. Being close to a Lagrange point doesn't mean you need _zero_ fuel, just a small amount. There's still the influence of the solar wind -- station keeping is inevitably necessary. As a result it doesn't really matter if a spacecraft is exactly at the Lagrange point or 100 km away from it, so there's no shortage of space. Also, this might be obvious, but it usually wouldn't make sense to park a spacecraft exactly at a Lagrange point because the spacecraft had to be moving in the first place in order to reach the Lagrange point. It would be a waste of fuel to slow down, so an orbit would typically be used instead.

HPsquared 5y ago
On the last part, does this mean it would orbit around the Lagrange point?
- mkesper 5y ago
  That's exactly what e.g. JWST does: https://www.jwst.nasa.gov/content/about/orbit.html https://www.jwst.nasa.gov/content/about/orbit.html

kryptiskt 5y ago

Both Gaia and Webb are at the same Lagrange point, but in completely different orbits around it (Here is a visualization: https://www.universetoday.com/155022/esas-gaia-just-took-a-picture-of-l2-neighbor-jwst/ https://www.universetoday.com/155022/esas-gaia-just-took-a-p...). There is a smattering of solar observatories at L1 too.

jug 5y ago

The L2 orbit is just an orbit around Earth but pretty far way; you can be anywhere along that orbit. :) https://static.scientificamerican.com/sciam/assets/Image/2021/saw0122Gsci31_d.png https://static.scientificamerican.com/sciam/assets/Image/202...

noselasd 5y ago

There's a zone around of about 500000 miles where the spacecrafts can place themselves in orbit around these points, there's plenty of room