Questions tagged [lagrangian-points]

Lagrangian points (also Lagrange points, L-points, or libration points) are the five positions (L1 - L5) surrounding two celestial bodies where gravitational pull of the two large mass bodies provides the centripetal force required to orbit them. Such points are usually nominally unstable but somewhat periodic around celestial systems with stable orbits.

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Would it be possible to Boost ISS to L1 or Lunar Orbit?

NASA and Russia plan to retire the ISS before 2030, and to launch a new lunar outpost to lunar orbit. This output could then be a gateway to future mission to Mars or the outer solar system. My ...
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Could a solar sail composed of smart glass stay near the L1 point of Venus?

From answers to this question i've learned that the Lagrangian L$_1$ point of Venus is not stable, despite the almost circular orbit of the planet and the fact that it has no moon. Nevertheless would ...
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Why put X-ray telescope Spektr-RG/eROSITA all the way out at Sun-Earth L2?

Per Wikipedia's Spektr-RG; Mission profile and orbit: Mission profile and orbit The spacecraft will enter an orbit around the Sun, at the L2 Lagrangian point, about 1.5 million kilometers away ...
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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. ...
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Is it obvious or easily-proven that L4 and L5 must be in the parental orbital plane?

Looking at the question and answer and diagrams from Are Lagrangian points associated only with the smaller body? got me wondering. L4 and L5 each form an equilateral triangle with the two main ...
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Are Lagrangian points associated only with the smaller body?

Diagrams of Lagrangian points I've seen always show the points near the smaller object, following its orbit about the larger one. For instance: from Wikipedia. But in fact the smaller object ...
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What is the required burn to keep a satellite at a Lagrangian point?

When a satellite reaches a Lagrangian point, it has a non-zero velocity $v_1$ because of the transfer orbit in which it had already been. What burn, say, $\Delta v$, one needs if the satellite is ...
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Details about traveling from EM-L2 to SE-L1

Would the optimal time to launch be when the Moon was on the opposite side of the Earth from the Sun? What direction would be optimal leaving EM-L2, radially away from the moon? Is the last line of ...
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Delta V to get to the Sun-Earth Lagrange Point 1?

For any of these starting positions, GEO, GTO, EM-L2 or EM-L4/5, which would require the least delta-V to get to Sun-Earth L1? How much delta-V would it require? Would this chart help in identifying ...
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Could JWST stay at L2 “forever”?

Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST ...
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Do horseshoe orbits have anything to do with Lagrange points? Do words fail us here?

I said (2010 SO16 is associated with Lagrange point L3 but wanders so far behind and ahead of it that the orbit is called "horseshoe"... and the comment was made: Not really. L3 is unstable. ...
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How will JWST maintain its elliptical orbit around L2?

I understand that JWST will have a vertical elliptical orbit around L2, but what I don't understand is how the telescope will actually maintain an orbit if there is no body in L2 to actually orbit ...
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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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Does launching to interplanetary space from LEO require the least delta-v?

Based on this chart from wikipedia, (I do not know if I am reading it correctly) This all assumes LEO-Eq LEO to C3/0=3.22 LEO to GEO to C3/0=3.9+1.3=5.2 LEO to EML-1 to C3/0=3.77+0.14=3.91 LEO to ...
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Gravity cancellation point [closed]

Here is a question from ANTHE: an exam in India. The question is:Two point masses M and 3M are placed at a L distance apart. Another point mass m is between on the line joining them so that the net ...
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Is the L2 Mars-Sun point protected from solar radiation?

To what extent is the L2 point protected in comparison to the surface, if at all? Since the L2 point might be in the umbra of Mars, it could be shielded against the sun. It would also be helpful if ...
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Nature of Hayabusa-2's “Home Position” relative to Ryugu? Is it Ruygu's L1?

This tweet "from Hayabusa-2" via JAXA shows the diagram below, which seems to suggest that the Hayabusa-2 spacecraft tends to remain between the asteroid Ryugu and the Sun. Does Hayabusa-2 have to ...
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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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Why are so many space telescopes placed in LEO instead of at Lagrange Points? And why do we hear about Hubble more than any Langrange-orbit telescope?

Here is the list of every space telescope launched by different space agencies - List of space telescopes. Most of the listed telescopes are placed in Lower Earth Orbit (about 95% of them). It's ...
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How does the delta V to reach and orbit L4 and L5 compare to entering orbit around the Moon?

The L4 and L5 Lagrange points, 60 degrees in front of and behind the Moon in its orbit around Earth, orbit at the same speed as the Moon. But when a spacecraft flies to the Moon, the gravity of the ...
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Could a radio telescope orbit Earth-Moon L2 so that it is in the Moon's radio shadow?

Chang'e 4, a Lunar orbiter and lander on the far side of the Moon, will put a relay satellite in a halo orbit around EML2 that also will do some low frequency radio astronomy. Since the Chang'e 4 ...
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Is communication from a spacecraft in SEL1 disturbed by the Sun?

A spacecraft at the Sun Earth Lagrange point one (1% of an AU, or one Solar diameter, from Earth towards the Sun) would have the Sun as its background. Is the Sun emitting strongly enough at ...
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Stationary Inter-planetary Satellite?

Is there a way to place a satellite in-between two planetary bodies such that the force from each gravitational pull is effectively nullified? In other words, is there any type of situation that would ...
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How Many Martian Lagrange points are there? …And are they useful for satellites?

I know that the Sun-Earth system has 5 Lagrange points, and there are five more Earth-Moon associated Lagrange points; so ten in all that are in some way associated with the Earth. Since Mars has two ...
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How far would the Mars L1 Lagrangian Point be from Mars?

I am a sci-fi writer, and I've heard about the concept of putting some type of magnetic deflector near the Sun-Mars L1 point to deflect charged particles from the Sun to reduce radiation effects on ...
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What was the probability that Osiris Rex would find Earth Trojans?

Orbits at the Sun-Earth L4 and L5 (where Earth-associated Trojan asteroids might reside) are not long term stable due to Jupiter's large perturbing effects. Jupiter is about 318 times more massive ...
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What are the sources of light at L2? How will the James Webb telescope be powered?

The James Webb space telescope will be positioned very close to L2. According to JPL, Webb will have a large solar-array to power itself. I don't understand how this works, since L2 is positioned "...
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When an object in an unstable Lagrange point falls away from that point, where does it end up? [duplicate]

I know L1-3 are saddle points in the potential, and thus small perturbations would cause an object at one of these points to accelerate away from the point, but where would that object end up? For the ...
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Ordering of the Lagrange points

Is there any basis for the ordering of the L-points? Specifically, is there any particular reason for choosing L1 as the first L-point?
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What is the period of halo/Lissajous orbits?

Does the orbital period of halo/Lissajous orbits around L1/2 points increase, decrease or stay the same when increasing the (average) orbital radius? A function period(radius,m1,m2) would be cool, ...
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Does it even make sense to talk about Mercury's triangular libration points (L4, L5)?

The recent question How much radiation shielding would be required for a habitat at Mercury–Sun L5? got me thinking. There are a large number of disadvantages and challenges to building or putting a ...
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How easy would it be to detect a large 400x1000 meters tubular habitat at L4

I'm writing an SF book and want to know if a 400 by 1000 meter tubular habitat at Lagrange point 4 (or L5) would be easily detected from earth?
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What is a “synodic frame”? Can one be defined for an elliptical orbit?

A description of a "synodic frame" was one of the main ingredients in this excellent answer to a question about an animation of a funky-looking orbit that several different and distinctly interesting ...
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This orbit looks wrong near a Lagrange point. Is it?

On a completely unrelated forum, i came across the following graphic: The orbit seems wrong to me, especially the first curve. From the initial trajectory, I would expect the orbit to have been in a ...
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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?
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Do we have the capability to place a satellite in the Sun-Earth L4/L5 Lagrange points?

I was looking at the Wikipedia page on Lagrangian points, and I noticed that in the list of current and proposed missions, the only mention of the $L_4$ and $L_5$ points is a "this would be a good ...
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Is there a synchronous orbital height for Phobos?

My assumption is that any body in the solar system would have it's own specific geo-synchronous orbit height. But when I took a look at Phobos and calculated the GEO height based on the simple formula ...
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Does the Milky Way have a Lagrangian point? [closed]

About 2.5 million light years from the Milky Way is the Andromeda Galaxy. We have about 4 billion years before the two collide as they approach each other things are getting to get interesting. But ...
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How will the Lucy spacecraft move from Jupiter's L4 to its L5 Trojan asteroids?

After having visited the L4 leading Trojans ("Greeks") of Jupiter, almost a decade after launch Lucy will spend almost 4½ years moving on to the trailing L5 Trojans, 5 AU away. Is there a special ...
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Why has the Earth-Sun libration point L1 been chosen over L2 for NEOCam to detect new NEOs?

above: Profoundly not-to-scale illustration of NEOCam in an orbit around the Sun-Earth libration point L1, about 1.5 million kilometers from Earth. Presumably Sun-shield and Earth-shield block light (...
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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 ...
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Burns for EML-1 to LLO

Wikipedia gives 0.64 or 0.65 km/s for going from LLO to EML-1 or back. I would like to know what the delta v of the specific burns involved are, and if my initial calcs are close, I don't see how ...
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Why does DSCOVR's camera EPIC see at least 13 sunrises and sunsets per day?

In this NASA Goddard YouTube video titled "One Year on Earth – Seen From 1 Million Miles", I've gotten stuck on the line In this view, EPIC sees the Sun rise in the west, and the Sun set in the ...
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Is this what station keeping maneuvers look like, or just glitches in data? (SOHO via Horizons)

I've been enjoying the JPL Horizons web interface and after I discovered the incredibly extensive database associated with SOHO (Solar and Heliospheric Observatory, also see sohowww.nascom.nasa.gov) ...
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How much delta v does it take to get to the Sun-Earth Lagrange 3 point?

How much delta v does it take to get to the Sun-Earth Lagrange 3 point? Also, Would higher delta-v allow a craft to get there much quicker? Would two hohmann transfer orbits be the most efficient ...
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Did ISEE-3 spend a few years in a halo orbit around sun-earth $L_1$ without using any fuel?

In a related question I'm trying to find some conclusive reference(s) helping explain if some halo orbits around the sun-earth or earth-moon $L_1$ or $L_2$ locations can actually be somewhat stable (...
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Are some Halo Orbits actually Stable?

UPDATE: I found another reference! While I always enjoy a good video starring Jimmy and Linda Carter, this one has Dennis Wingo describing ISEE-3's original Halo orbit. He describes Sun-Earth $L_1$ as ...
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Are large halo orbits around L₁'s and L₂'s preferred over small orbits for reasons other than geometry?

There have been many examples of the placement of satellites in orbits around Lagrange points, most have been sun-earth and earth-moon $L_1$ and $L_2$ due to their proximity to earth. In each case ...
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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. ...
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Why would Hollywood's Planet X (at earth's L3) be unstable?

This NASA website states "NASA is unlikely to find any use for the L3 point since it remains hidden behind the Sun at all times. The idea of a hidden "Planet-X" at the L3 point has been a popular ...