Linked Questions

19 votes
6 answers
8k views

What artificial satellite has the farthest orbit around the Earth?

What is the furthest Earth orbiting satellite? What is its speed and purpose?
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  • 1
15 votes
1 answer
17k 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 ...
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  • 148k
5 votes
1 answer
4k views

LOPG/Deep Space Gateway - What is a cislunar orbit?

Formerly the Deep Space Gateway and now the Lunar Orbital Gateway or LOPG station, is planned for Expedition 1 aka the maiden launch of the SLS. After reading several specifications, to avoid the "...
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8 votes
2 answers
237 views

What is the current state of commercial space stations?

Many years ago, in the 2005 - 2010 area, it seemed like there were a lot of proposals to create commercial space habitats. These included inflatable modules, usage of spent fuel tanks, and ...
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  • 213
8 votes
1 answer
385 views

How does a butterfly orbit move in 3D? Way to generate or visualize?

The paper Earth-Moon Near Rectilinear Halo and Butterfly Orbits for Lunar Surface Exploration (AAS 18-406) says Periodic Orbits in the Earth-Moon System The current investigation focuses on three ...
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  • 148k
7 votes
2 answers
592 views

Do Lagrangian points apply to eccentric orbits or binary systems?

The assumptions about the Lagrangian points being stable (...in the traditional meaning of the word: not moving around; they are unstable in the mathematical sense, except for arguably L4, L5) that I'...
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  • 52.6k
4 votes
1 answer
709 views

How much delta-v does it take to get from a Lunar Transfer Orbit to a Near Rectilinear Halo Orbit around the moon

There has been a lot of talk of NASA putting a Lunar Gateway in a Near Rectilinear Halo orbit around the moon, but I don't actually know how much delta-v it takes to get there. Most delta-v maps I can ...
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  • 1,013
4 votes
2 answers
1k 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 ...
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  • 148k
1 vote
1 answer
474 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 ...
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  • 11
6 votes
2 answers
314 views

Is the Gateway's halo orbit bound to Earth? Would the Gateway remain in Earth orbit if the Moon disappeared?

Discussion below this answer involves my feeling that calling halo orbits in very asymmetric systems (e.g. Sun-Earth or Earth-Moon) as orbits around the primary, in 1:1 resonance with the secondary. ...
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  • 148k
4 votes
2 answers
278 views

Can mascons have Lagrange-like points? In principle? At the Moon?

Background Lagrange points are a mathematical consequence of the The Circular Restricted Three Body Problem (CR3BP or CRTBP); two massive bodies orbiting around their center of mass and a third ...
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  • 148k
0 votes
2 answers
173 views

What is the connection (if any) between the new Artemis mission and the two Artemis spacecraft (Themis-B, -C)?

It has been announced that the culmination of Space Policy Directive 1, the goal to land Americans and specifically the first woman on the Moon, at it's south pole in 2024 will be called "Artemis&...
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  • 148k
3 votes
1 answer
587 views

Rendezvouses in halo or lissajous orbits

If a spacecraft was in an EM-L2 halo/lissajous orbit, and another craft would was going to approach EM-L2 a few days later, could they rendezvous immediately or is there a limitation when the second ...
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  • 6,747
1 vote
2 answers
228 views

How to prepare for an interview for a Pure Mathematics position at ISRO's Space Application Center?

I have completed a Master's in Pure Mathematics. I have read topics like Abstract Algebra, Linear Algebra, Functional Analysis, Topology, Cryptography, Course in C++, etc. Recently I found an ...
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6 votes
1 answer
201 views

Aspects of "true deep space environment" on Gateway not thoroughly explored by decades of habitation of nine space stations already?

The ABC News article President Trump prompts state of confusion over space policy with tweet covers POTUS' tweet and NASA director Bridenstine's clarification tweet a few hours later, as well as cites ...
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