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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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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Are there really just 5 Lagrange points?

In many online resources, like Wikipedia, five Lagrange points are specified. From my understanding, a Lagrange point is a point where the gravitational attractions of the two bodies (Sun and Earth, ...
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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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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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Are the Earth's 10 Lagrange points stable and large enough to park multiple satelites/space vessels

I know that we already have satellites in position at our Lagrange points, but what if we want to use them to park spacecraft sections for assembly reasons, or possibly even a meteorite for mining. ...
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Do objects at the $L_4$ and $L_5$ points conserve angular momentum?

A planet in an elliptical orbit around a star conserves angular momentum. (This is tantamount to saying that it sweeps out equal areas of the ellipse in equal times). If conditions are such that ...
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Minimum Delta V to a staging area in cislunar space for a vertical space gun

Space guns have a lot of confounding factors for getting to LEO. The projectile must be a rocket capable of large delta v in order to circularize the orbit. Then, giving more sideways velocity ...
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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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Does the Earth have any Trojan asteroids?

Are there any known Trojan objects residing in the Sun-Earth L4 (SEL4) and L5 (SEL5) Lagrange points, also named "Greek" and "Trojan" groups, respectively?
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Any satellites in Earth-Sun L3 point?

Do we (the humanity) have any satellites in the Sun-Earth $L_3$ point? If not, then what are the plans to put some ships into this point?
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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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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 from ...
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Are L1 to L2 and back “cheap” transfers/cyclers possible?

This paper studies transfers from halo orbit to halo orbit in the Jovian system. I wonder if there are any locally stable orbits connecting Earth-Moon L1 and L2 points. EDIT: One should also consider ...
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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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How can Sun-Jupiter Lagrangian points be used by flyby probes?

Sun-Jupiter L1 is 1/3 of an AU from Jupiter. Could it be used to slow down or redirect a spacecraft approaching Jupiter? And the same for Sun-Jupiter L4 and L5 for a spacecraft on the way to e.g. ...
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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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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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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 ...
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'Orbiting' Earth-Moon $L_1$

I'm a Sci-Fi author, trying to keep the physics real in my books. I am in the process of moving a space station to the Earth-Moon $L_1$. I've read that a vessel can't just sit at that point, but has ...
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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 ...
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How can I calculate the Characteristic Energy to Sun-Earth L1?

Alternatively, does anyone know it? I'm asking in regards to the upcoming DSCOVR (Deep Space Climate Observatory) mission scheduled to launch aboard a Falcon 9 v1.1 rocket in January 2015. DSCOVR is ...
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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 ...
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Do Lagrange points still exist if there is significant radiation pressure on the third body from the first?

From this answer: To obtain the distance to L1, find the smallest value of $r$ such that $$\frac{M_2}{r_1^2} + \frac{M_1}{R^2} - \frac{r_1(M_1+M_2)}{R^3} - \frac{M_1}{(R-r_1)^2} = 0.$$ To obtain the ...
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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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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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What would be the delta-v of rendezvousing with temporarily captured asteroids in Sun-Earth L-points?

It is believed that at any point in time, a handful of small asteroids (TCO's) are temporarily orbiting the Sun-Earth Lagrange points 1 & 2. They are random samples from the Asteroid Belt and ...
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Why are the Trojan libration points equidistant and not mass weighted?

The locations of the collinear Lagrange points L1, L2, L3 are mass weighted, so for example Sun-Earth-L1 is only 1% of the distance to the Sun from Earth. But L4 and L5 are one AU from both the Sun ...
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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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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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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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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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How should I understand these phrases in this paper on orbit transfers?

I am studying this article on orbital mechanics and can't understand the meaning of some terms related to mathematics (perhaps because my native language doesn't have such terms). I created the same ...
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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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What does the term “libration point gateway” mean?

In the Circular Restricted Three Body Problem, natural paths exist between periodic orbits or the libration points that have negligible cost. These are commonly known as free transfers between ...
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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 it feasible to put a comet into a Lagrangian point?

How feasible would it be to put a large comet, like the one that Philae landed on, into a Lagrangian point, or some other spot that would make it convenient & SAFE for mining, colonization, ...
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Libration points - Science prospects

There have been quite a few missions to libration points. As far as the dynamical possibilities are concerned, libration point vicinity offers a spectrum of orbit profiles. What science data is not ...
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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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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 big would a collection of asteroids near the Moon's L4 point need to be to aggregate naturally into a “stepping stone” for space exploration?

Wouldn't it be useful to catch few meter sized near-Earth asteroids whenever opportunity knocks and "lock them up" at the L4 Langrangian point of our Moon ? Although at the L4 and L5 Lagrangian ...
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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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Who called the Lagrangian points as “Libration” points and and why was the terminology “Libration” used?

I am curious about the naming and why were the equilibrium solutions of the CR3BP called as Libration points? Who called them that and what is the history behind it?
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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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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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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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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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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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What is the radiation level at the L2 Mars-Sun point?

This answer shows that the radiation levels at the L2 Mars-Sun point will be lower because it lies within Mars' solar umbra. So what will the level of radiation be at the L2 Mars-Sun point? Also, how ...
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How can you construct the periodic orbits around libration points L1 and L2 in the circular restricted three-body problem and prove their existence?

Following up on a previous question about the classification of periodic orbits, how can they be constructed, especially the planar Lyapunov family, around libration points $L_1$ and $L_2$? And how ...
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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 ...