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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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How bad is a non-Lagrangian Point orbit?

I am no expert on space physics, just an interested amateur. I've been searching for a few weeks and having a hard time gaining insight on this question. Phrasing the question more specifically: how ...
David M. Perlman's user avatar
12 votes
3 answers
3k views

How does a satellite's mass affect its fuel consumption to maintain orbit?

Given two otherwise identical satellites in identical orbits, the more massive one's orbit decays more slowly from atmospheric drag: $F=ma$, same $F$ (drag), bigger $m$, so smaller $a$ (decay). So ...
Camille Goudeseune's user avatar
1 vote
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82 views

How to maintain minimum distance between satellites for duration of their orbits

I am working on a simulation in python that involves propagating hundreds of satellites over time. For simplicity, let's assume I have satellites at only a single inclination separated into multiple ...
Luca Petrescu's user avatar
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80 views

Why does the the Artemis I translunar flight (have to) last 6 days while the Apollo fights to the Moon lasted only about 3 days? [duplicate]

Does the Artemis I flight to the Moon have to last so long compared to the about 3 days long lasting Apollo flights because the Orion spacecraft has to enter into a distant retrograde orbit (DRO) ? Or ...
Cornelis's user avatar
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3 votes
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The Earth's rotation does change by small amounts; what is done to keep geostationary satellites aligned with ground stations? [duplicate]

Are satellites moved to keep them aligned? Are they at risk of becoming unusable from the small, but measurable changes to Earth's rotation?
Ken Fabian's user avatar
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7 votes
1 answer
953 views

What size are the typical keep-inside boxes of geostationary telco satellites?

Geo sats need station-keeping and the size of their keep-inside box is a design parameter. A smaller box implies more manoeuvres to stay inside the box. All depending on the various orbit ...
Bash Frank's user avatar
2 votes
0 answers
44 views

What size of a solar sail would you need to overcome orbital decay? [duplicate]

Specifics of the question: Placed into a 400km 0 inclination orbit 10 kg 20cm cube Able to orient itself in any direction Let’s say we want this satellite to be able to indefinitely orbit earth. ...
Topcode's user avatar
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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 ...
cms's user avatar
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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 ...
cms's user avatar
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5 votes
1 answer
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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, ...
Sheldon's user avatar
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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 ...
BradV's user avatar
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4 votes
1 answer
128 views

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 ...
Sheldon's user avatar
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23 votes
2 answers
4k views

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 ...
Stilez's user avatar
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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 ...
Sheldon's user avatar
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0 answers
438 views

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 ...
nealmcb's user avatar
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2 answers
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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 ...
Ng Ph's user avatar
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1 vote
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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 ...
uhoh's user avatar
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1 answer
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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? ...
Auberron's user avatar
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18 votes
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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 ...
Roger Wood's user avatar
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4 votes
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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 ...
Camille Goudeseune's user avatar
12 votes
2 answers
3k views

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?
Slarty's user avatar
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1 vote
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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 ...
Onur Gürdoğan's user avatar
4 votes
1 answer
389 views

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 ...
uhoh's user avatar
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2 votes
0 answers
75 views

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?
Joe Jobs's user avatar
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1 vote
0 answers
632 views

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 ...
Joe Jobs's user avatar
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3 votes
0 answers
251 views

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 ...
Ricardo Casimiro's user avatar
3 votes
1 answer
507 views

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?
Ricardo Casimiro's user avatar
1 vote
0 answers
169 views

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 ...
Erkin Alp Güney's user avatar
3 votes
1 answer
212 views

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....
Elisa Fitri's user avatar
5 votes
1 answer
689 views

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 ...
Elisa Fitri's user avatar
3 votes
2 answers
194 views

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?
Bob516's user avatar
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0 answers
94 views

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 ...
Bob516's user avatar
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9 votes
2 answers
856 views

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 ...
uhoh's user avatar
  • 149k
4 votes
1 answer
143 views

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 ...
ivric's user avatar
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1 vote
3 answers
349 views

Could a framework of mirrors static in space above the Lunar south pole illuminate a moonbase there continuously?

Edit: For clarification of what I mean with "static in space above the Lunar south pole " please see this answer from @Tom Spilker or his answer to the question Orbits that allows ...
Cornelis's user avatar
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2 votes
1 answer
123 views

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 ...
Justin Braun's user avatar
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6 votes
2 answers
426 views

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 ...
C. McCracken's user avatar
4 votes
1 answer
3k views

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 ...
HardcoreBro's user avatar
17 votes
4 answers
5k views

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 ...
user avatar
2 votes
2 answers
253 views

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 ...
Muze's user avatar
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4 votes
1 answer
376 views

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 ...
Muze's user avatar
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3 votes
1 answer
140 views

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 ...
Eviatar.E's user avatar
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6 votes
1 answer
822 views

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 ...
karthikeyan's user avatar
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11 votes
1 answer
1k views

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 ...
uhoh's user avatar
  • 149k
12 votes
1 answer
865 views

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)...
costrom's user avatar
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16 votes
4 answers
990 views

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 ...
Magic Octopus Urn's user avatar
3 votes
1 answer
1k views

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 ...
Bruno's user avatar
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2 votes
2 answers
174 views

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 ...
Sam G.'s user avatar
  • 115
3 votes
1 answer
691 views

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 ...
Capeboom's user avatar
  • 283
2 votes
1 answer
690 views

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. ...
Capeboom's user avatar
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