Linked Questions

26 votes
3 answers
6k 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 ...
TheEnvironmentalist's user avatar
18 votes
2 answers
5k views

James Webb telescope; limits to propellant lifetime?

There is a comprehensive article on Wikipedia on the James Webb telescope. It includes a statement regarding the operational lifetime being nominally five years and optimistically ten years. However ...
Roger Wood's user avatar
  • 3,894
5 votes
4 answers
431 views

Have space probe gone to unplanned destinations?

Reading this question about multiple gravity assists (Why is Voyager 1 faster than all other space probes?), it caused me to wonder if any probes have been redirected to additional (or alternate) ...
Milwrdfan's user avatar
  • 2,798
14 votes
3 answers
9k views

How to best think of the State Transition Matrix, and how to use it to find periodic Halo orbits?

I'll state my mathematical question about the state propagation and state transition matrices first, then show you a simple problem for which I would like to use these concepts to generate a densely ...
uhoh's user avatar
  • 149k
9 votes
5 answers
2k views

Stability of Lissajous orbits around Sun-Venus L1

How far is it from the Venus? Does Mercury gives too big perturbations for a stable Lissajous orbit?
Milkman's user avatar
  • 193
15 votes
1 answer
3k views

How many satellites can stay in a Lagrange point?

Lagrange points as I understand it are points in space between 2 objects where the gravitational pull between them is effectively equal. That makes station keeping at these points relatively easy. ...
David says Reinstate Monica's user avatar
14 votes
2 answers
2k views

Can the James Webb Space Telescope basically manage its own orbit if necessary?

In this great answer I learned that the Mars rover Curiosity can be given some tasks and it will go ahead and manage the work and navigation by itself, to at least a certain limit. The James Webb ...
uhoh's user avatar
  • 149k
6 votes
2 answers
3k views

What is the altitude of a surface-synchronous orbit around the Moon?

A geostationary equatorial orbit (GEO) is a circular geosynchronous orbit in the plane of the Earth's equator with a radius of approximately 42,164 km (26,199 mi) (measured from the center of the ...
Joe Jobs's user avatar
  • 2,650
11 votes
1 answer
3k views

What is the difference between halo orbits and Lissajous orbits?

The Wikipedia articles for halo orbit and Lissajous orbit leave me wondering how these two orbits are different from an orbital mechanical point of view. Could they be discussed together here, so I ...
uhoh's user avatar
  • 149k
10 votes
2 answers
3k views

The design of the halo orbit of the James Webb Space Telescope

As I feel a little less uncomfortable with "halo" orbits, with this question, I would like to explore the practical aspects, in particular those related to the design of the James Webb Space ...
Ng Ph's user avatar
  • 2,749
16 votes
3 answers
1k views

Spacecraft Maneuvers as Intellectual Property? Wow!

In the past I had encountered a few mentions of orbits being patented (or at least applications filed) but didn't take much notice. Then I did a simple search and was blown away by the sheer volume of ...
uhoh's user avatar
  • 149k
4 votes
2 answers
577 views

Are there some three-body orbits that can't be escaped? Can we know without propagating forever?

update: Searching for "choreographies" I found this Physics SE question which is related but different because it asks only if periodic solutions can be proven to be periodic numerically and my ...
uhoh's user avatar
  • 149k
3 votes
1 answer
1k views

How likely will the James Webb Telescope encounter debris trapped at L2?

Do Lagrangian points collect micro-meteorites similar to how the Pacific trash vortex collects debris? I was wondering if the James Webb Telescope will have to clear its Lagrange point before ...
Gabriel Fair's user avatar
  • 1,331
9 votes
1 answer
324 views

If James Webb goes "over the hill" is it gone for good?

James Webb is in a Halo orbit around Earth's L2 point. It is in a gravitational saddle: two directions are stable ("up-down" and "front-back"). The "in-out" direction is ...
Kevin Kostlan's user avatar
1 vote
1 answer
642 views

L2 point in multi-moon system

For an SF novel, if there were two large moons orbiting a planet, let's say one moon the size of Earth's moon and the 2nd moon about 20% larger, and the planet roughly the size of the Earth, would the ...
Phil's user avatar
  • 31

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