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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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3 votes
0 answers
96 views

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 ...
12 votes
4 answers
1k views

Can solar sail prevent orbital decay?

I can imagine a satellite with a solar sail it rolls when on the night side of Earth, then unrolls near "afternoon", propelled on each past of its "sunset side" of travel. Would such system be a ...
12 votes
3 answers
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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 ...
1 vote
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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 ...
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 ...
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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 ...
5 votes
0 answers
437 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 ...
3 votes
1 answer
132 views

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?
4 votes
1 answer
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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 ...
5 votes
1 answer
299 views

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, ...
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 ...
2 votes
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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. ...
3 votes
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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 ...
2 votes
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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 ...
6 votes
2 answers
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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 ...
23 votes
2 answers
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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 ...
6 votes
1 answer
891 views

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 ...
17 votes
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 ...
13 votes
1 answer
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What kind of thrusters will the James Webb Space Telescope use for station keeping?

Question is fairly self-explanatory, but I couldn't find an answer on Google. I would expect ion thrusters because of their efficiency. Thanks!
10 votes
2 answers
3k views

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 ...
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 ...
3 votes
1 answer
928 views

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? ...
18 votes
2 answers
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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 ...
4 votes
1 answer
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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 ...
12 votes
2 answers
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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?
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 ...
12 votes
1 answer
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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)...
12 votes
2 answers
710 views

How can just making the ground broadcast stronger neutralize a zombie(sat)?

In April of 2010 the Geo-not-so-stationary satellite Galaxy-15 stopped responding to ground commands. It operates as a "bent-pipe" or Transponder system, which means - roughly speaking - it will ...
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 ...
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 ...
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 ...
2 votes
0 answers
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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?
3 votes
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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 ...
1 vote
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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 ...
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?
18 votes
2 answers
2k views

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) ...
3 votes
1 answer
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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....
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 ...
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 ...
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 ...
4 votes
1 answer
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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 ...
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?
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 ...
1 vote
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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 ...
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 ...
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 ...
3 votes
1 answer
690 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 ...
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 ...
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 ...
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 ...