Questions tagged [station-keeping]

Operations done to keep a spacecraft in a particular orbit. Generally done by by thruster burns. In LEO this must be done to counteract the momentum loss to atmospheric drag. In other orbits it may be needed to maintain a planned relative position over a long period of time.

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What formation-keeping software does MMS use?

The Magnetospheric MultiScale (MMS) mission is a NASA mission consisting of four satellites arranged (at apogee) in a tetrahedral formation. According to this 2015 source: On Oct. 15, 2015, a NASA ...
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What formation-keeping maneuvers are required by MMS?

The Magnetospheric MultiScale (MMS) mission is a NASA mission consisting of four satellites arranged (at apogee) in a tetrahedral formation. According to this 2015 source: On Oct. 15, 2015, a NASA ...
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Has JWST done its first station keeping yet?

Has JWST done its first station keeping yet? The last burn I know about was the MCC2 burn on Jan24; more than 21 days ago; and that was a pretty long burn with a $\Delta v$ of 1.6 m/sec or 160 cm/sec, ...
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How frequent are (or will be) JWST station keeping burns at L2?

Does anyone have solid information regarding the scheduled/anticipated station keeping burns for JWST at L2? In an online video I've heard mention of 'every 21 days' which at first look seems ...
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How much margin does JWST have for station keeping in Halo orbit?

How much margin in $\frac{m}{s}$ does JWST have for station keeping in Halo orbit? JWST must always stay on the earth side of the L2 saddle since thrusters only point towards the sun. Also` solar ...
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Since L2 has no visible marker, how will James Webb's ground control determine its relative position and velocity for station keeping?

James Webb will be in a halo orbit, station keeping around the Sun-Earth L2 point. This means it needs to monitor its position with regard to L2, for periodic station keeping purposes. But L2 isn't an ...
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How much fuel did JWST save due to an accurate launch, and how much will remain after L2 orbit?

How much fuel did JWST save due to an accurate Arianne 5 launch, and how much fuel will be remaining after JWST L2 orbital insertion? And how many years is that fuel expected to last? According to ...
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Is JWST actually in a Lissajous orbit? What will it look like? Implications for station-keeping?

Note: for lots of great background related to this question, see lagrangian points - The design of the halo orbit of the James Webb Space Telescope - Space Exploration Stack Exchange There are ...
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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 ...
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Do operational Starlink satellites run their ion engines at night on batteries? And if so, do they have hi/low settings?

Discussion below What is the maximum thrust of the Starlink satellites? raise the question of the Starlink communications satellites' power budget and use of their ion thruster in daylight when the ...
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How do RAAN steering increase the launch window?

In the recent ULA video by Tory Bruno Tory Talk // Atlas V Lucy: RAAN Steering (linked below) he gave some short hints about RAAN steering. What is RAAN (Right Ascension of Ascending Node) steering? ...
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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 ...
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Exoplanet orbitable in permanent umbra?

Does any planet, or Kuiper Belt Object, or exoplanet measured or surmised, orbit its star either fast enough, or slow enough and thus distantly enough to cast a long enough shadow, for a spacecraft to ...
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Are any Earth orbits in continual shadow of the Earth?

Do any orbits around Earth leave the spacecraft in permanent shadow? If not, what is the minimum amount of time that a spacecraft must be exposed to sunlight on average?
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Right Ascension of the Ascending Node (RAAN) Drift and Correction

This one can be a very short and easy question, but I wanna know the proper answer of them.. Few days ago I got a questions like: "What kind of perturbation(s) can cause drift on RAAN value of a ...
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Station-keeping delta-v per year for an Earth-Moon vanilla halo orbit?

This answer reminds us that an Earth-Moon L1 or L2 vanilla1 halo orbit remaining always visible to some patch on the Moon's surface requires station-keeping. Queqiao uses such an orbit having ...
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How much hydrazine does an Iridium satellite start with? How much does it use per year?

Iridium satellites use hydrazine and the spacecraft are expected to last at least 15 years. How much hydrazine do Iridium satellites start with, and if possible, roughly do they use per year?
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How much krypton do Starlink satellites carry when they are first deployed?

Starlink satellites use krypton as propellant. This answer roughly estimates 2.3 kg of Krypton based on a total delta-V of 190 m/s and an exhaust velocity of 20,000 m/s. But how close is that to ...
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Thruster firing time for station keeping

I am simulating the example of LEO station keeping in GMAT with a delta-v thrusters of 2.5m / s, my question is how can I determine the time in which the thrusters act to raise the height of the orbit ...
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Delta-V for station keeping

How can I calculate the necessary thrust to keep a satellite of 1 kg mass in orbit, for a Delta-V of 2 m/s, knowing that the correction force must be done once a month for 900 seconds?
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An orbit in the corner of isosceles right-angled triangle

Is it possible to have a non-escape orbit that is equidistant to two celestial bodies (for example, Earth and Mars) at all times? If possible, how much does it cost to keep an object (which is much ...
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Inclination Maneuver of GEO Satellite

I have performed inclination maneuver for GEO satellite at ascending or descending node. The inclination of the satellite is 0.05 deg. Then I performed the maneuver so the inclination change to 0....
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Station Keeping East-West Maneuver

A GEO satellite spends 14 days in longitude deadband (+/-0.067 deg). At the 14th day, I want to perform an east-west maneuver. But I am uncertain what time I should perform the maneuver at the 14th ...
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Spacecraft remaining at station-keeping with respect to the ISS

If any spacecraft has remained at station-keeping with respect to the ISS for 12 hours or more, how far from the station did the craft remain?
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What terminology is used to describe spacecraft in stationkeeping?

Forgive any inaccurate wording of this question. If a Soyuz craft which had been docked at the Zvezda module backed away from the ISS and remained at stationkeeping, would NASA, Roscosmos, or the ESA ...
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How do stable equilibrium points work in GEO? If all geosynchronous spacecraft suddenly lost stationkeeping, would most "fall into" one or the other?

The (currently unanswered) question Quantitatively, how deep are the stable equilibrium points in GEO? How much delta-v to move from one to the other? (also see comments at Delta-v to move from GEO to ...
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How satellite orbital vacancies are determined?

Before a new satellite is launched, its desired orbital altitude, inclination is determined. Now with thousands of satellites already in orbit at different altitudes, how do we know if our desired ...
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Could a framework of mirrors static in space above the Lunar south pole illuminate a moonbase there continuously?

When near the south pole of our Moon a permanent human community is established to search for and produce water in the permanently shadowed regions there, it would be nice to have some light from ...
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Reactionless Electrodynamic Propulsion in LEO

Put simply, the earth has a large magnetic field ranging in intensity between .25 and .65 Gauss. Would it not be possible to use the earth's magnetic field as a stator and electromagnets within a ...
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What orbit would a space station need to stay in orbit for N years?

(posted before on physics stackexchange but was told to come here) I'm reading this book which has a post-apocalyptic setting. At one point you look at the earth from the view of a 1000-year-old ...
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How much Delta-V is needed for Orbital Maintenance?

My question is aimed at understanding the how much Delta-V is needed for orbital maintenance in different orbits. Obviously, there still is some residual air resistance that decreases as the orbital ...
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4 answers
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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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Could solar sails be used in station keeping?

Could solar sails work in place of solar vanes for passive stabilization in station keeping a satellite fixed in the Lagrange 2 point on a parallel orbit with the Moon? Related: What is the ...
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Could a ball of water stay in orbit?

Could a water bubble (spherical occlusion of water in air or vacuum) similar to the one in the picture below remain in Earth orbit without evaporating, dispersing, or disintegrating? Assume the orbit ...
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Tesseral Part of the Geopotential

I am working on the design of a constellation for academic purposes. I try to describe a phenomenon that appears in the simulations by means of analytic expression and I can't really find a good ...
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Why are 22N and 440N liquid engines quite common?

One can often spot that liquid apogee engines are 440 N and attitude control systems are 22 N. Is there a reason why the thrusts are proportional? If the engines are scaled for reducing development ...
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Do operating GPS satellites ever make orbital maneuvers for station-keeping?

Since GPS satellites need to face the Earth, they might execute momentum-unloading from time to time using pairs thrusters so as to produce torque but minimal change in the orbit, but I am guessing ...
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Why do GPS (but not GLONASS or Beidou) satellites have increasing eccentricity over time?

When comparing GPS, Beidou, Galileo, GLONASS, and potentially other GNSS, we can see that the eccentricities of GPS spacecraft are increasing with time (i.e. apogees increasing and perigees decreasing)...
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Why is the US building a Lunar Orbital Platform-Gateway (LOP-G)?

An excerpt taken from the Wikipedia page on LOP-G says space-experts have criticized it: The Deep Space Gateway has received criticisms [...] for lacking a proper scientific goal. Former NASA ...
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How to calculate thruster force calculation during maneuvers

I'm working in a satellite operator company, operating a GEO cubic shaped satellite, with 16 chemical thrusters and 3 reaction wheel for attitude control maneuvering. We have vendor provided flight ...
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Zero propellant thrusters

Is it possible to create thrusters for station keeping that require no fuel? Are there ideas similar to solar sails which can help in station- keeping and make use of a natural phenomenon? Except the ...
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How to calculate the change in inclination due to perturbations?

I would like to know the how much the inclination for a generic elliptical orbit changes over an unspecified period. The variation of inclination fluctuates as per a thread listed at the bottom. I'd ...
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Budgeting delta-v for atmospheric drag when orbit is elliptical?

I'm trying to calculate the delta-V budget to maintain a generic elliptical orbit. Looking at the atmospheric drag losses I can only find equations that calculate delta-V loss for circular orbits. ...
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Centrifugal Space Station design

If a Space Station designed around centrifugal forces being essential for gravity was to be constructed similar to the fans of a helicopter blade like the image below, how would it differ from a ...
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Satellite altitude variances in orbit

I understand that all satellites must have burn corrections to keep their orbits where they are needed. However my question is specifically about what those changes are in magnitude from the desired ...
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Xenon vs Hydrazine, "Should I Stay or Should I go?" Dawn mission decisions

edit 2: There seems to have been some announcement/extension by NASA (20-Oct-2017), possibly this will shed more light on the issues in this question. edit 1: Several months have passed since this ...
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Moon orbit station-keeping delta-V budget

I am looking for examples of station-keeping delta-V budgets from lunar orbiters to verify the results of an orbital-perturbations programm that I wrote for my master thesis. Any indication on where ...
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Will the ISS have electric propulsion to maintain altitude? Is there enough power for it?

In April 2014 this comment was made below the question What propulsion methods does the ISS use for station-keeping?: In November they said in three years, so perhaps late 2016. Since such claims ...
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extreme longevity of geostationary orbits

I was speculating that geostationary satellites could be around possibly for billions of years (i.e. much beyond the point where plate tectonics would have erased all traces of human civilization on ...
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What factors would make station-keeping of an Areostationary Mars satellite necessary?

This answer introduced me to the word Areostationary Orbit - (hint, comes from Ares), an orbit that would remain stationary above a point on the equator of Mars. The article mentions that ...
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