Linked Questions

25
votes
3answers
5k views

What is the "mass" of a Lagrange point?

Of the five Lagrange points, L4 and L5, as stable points, can be orbited by asteroids, satellites, and any other useful or interesting object. Assuming two-body motion however, calculating orbits with ...
15
votes
1answer
16k views

What is a near rectilinear halo orbit?

A proposed option for the lunar orbit of a Lunar Orbital Platform-Gateway (formerly known as Deep Space Gateway) is a near rectilinear halo orbit, or NRHO. This excellent answer discusses the ...
17
votes
4answers
3k views

Are some Halo Orbits actually Stable? (stable orbits about unstable Lagrange points)

update: some more sources; the broken site spacecraftforall.com/a-new-orbit used to have an interactive simulation, here's an old screen shot: Hat tip to @NgPh for finding this Space College page ...
7
votes
2answers
976 views

What determines the orbital speed around a massless Lagrangian point?

What value of M should I use to calculate the speed of a satellite orbiting a Lagrangian point where there exists no mass?
11
votes
1answer
6k views

Why is a near rectilinear halo orbit proposed for LOP-G (formerly known as Deep Space Gateway?)

Why is a near rectilinear halo orbit a good place for a Lunar Orbital Platform-Gateway (formerly known as Deep Space Gateway)? Are there specific logistical and orbital-mechanical advantages over ...
15
votes
1answer
976 views

Do we sufficiently understand mechanics of Lagrange point stationkeeping for EML2 rendezvous and assembly?

I've been watching some recorded videos from the April 22 - 24, 2014 Humans2Mars conference (videos and live streams, when available, are on the National Institute of Aerospace channel on Livestream), ...
6
votes
1answer
602 views

How Moon and other planets affect Earth-Sun lagrange points locations?

We can calculate Earth-Sun Lagrange points based on Sun & earth mass/gravity. However moon and other planets must be affecting the location of these points. How this effect is analyzed and exact ...
11
votes
1answer
832 views

What sort of orbital elements are used to describe halo orbits?

For standard orbits we can use Keplerian elements, TLE, or other similar. These don't make much sense for Halo orbits, which are not around a central body, but around a Lagrangian point, and follow an ...
5
votes
1answer
677 views

Do Lagrange-like regions temporarily appear around planets with multiple moons?

Lasting Lagrange points only exist where two bodies of mass dominate. But in the midst of for example the synchronous Jovian moons, is there a calendar and map for when a spacecraft can be near enough ...
4
votes
2answers
920 views

How will the Lunar Gateway go to L2 and L1; how much delta-v is needed?

In a talk to the press which can be heard in the YouTube video NASA Administrator Jim Bridenstine Explains the Lunar Gateway, NASA director Jim Bridenstine says after about ...
5
votes
1answer
208 views

How much does the tidal effect affect satellites in a retrograde orbit?

How much more unstable are satellites in retrograde then a pro-grade orbit? Does the stability of a retrograde orbit increase with altitude? This answer said this orbit is unstable and made me think,...
2
votes
1answer
342 views

What do the green lines represent in this Lagrange Point animation?

This is one of my all-time YouTube favorite videos. It's an illustration of the Earth-Moon Lagrange points in orbit around the sun for a year. Put on your headphones, dim the lights, and set YT to HD. ...
2
votes
0answers
442 views

How to find Near Rectilinear Halo Orbits (NHROs)?

Looking all the good questions and answers in this site referent to CR3BP dynamics, periodic orbits, state transition matrices, etc. I wonder: what algorithm or steps do I have to follow to find the ...
1
vote
1answer
187 views

Distant retrograde Orbit in CR3BP Question

How can i calculate the initial vy0 component for a distant retrograde orbit in Sun-Earth CR3BP around Earth?
1
vote
0answers
232 views

Cis-L2 Libration Point Halo Orbit

Queqiao became the first satellite to orbit the Cis-L2 libration point (far side of the moon). Link: https://en.wikipedia.org/wiki/Chang%27e_4 Does anyone have any insight on how to model this orbit ...