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Questions tagged [orbital-maneuver]

In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.

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What are common guidance strategies for a finite orbital maneuver?

Suppose we have our spacecraft in a circular orbit around the Moon and we want to transfer it to an elliptic orbit with a medium-thrust (10-100N) retrograde burn. Based on the current state estimate, ...
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How to match orbital speeds of 2 or more satellites in different orbits?

Satellite ME is orbit around the Moon and Earth. Satellites E is around Earth. I understand the low orbit satellites orbit at higher speeds. Can Sat ME match the speed of any of Satellites E at any ...
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Will an array of multiple ion engines still be more efficient than a single chemical engine?

I was just thinking the other day and got this idea out of my head. I'm not an aerospace expert or anything even close to it, so please understand even if this turns out to be a really basic question: ...
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Meteosat 11 big deboost/reboost

Before Feb 2018, the meteosat 11 (MSG-4) were periodically reboosted approximately every 85 days: EDIT: added the orbital inclination plot to show the clearly visible variation to both semi-major ...
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Was the gravity turn used in early spaceflight?

Reading through the Wikipedia article about Gravity Turn, specifically the Use in spaceflight section, it seems that the Gravity Turn was not used in early spaceflight. Is that correct? For example, ...
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Piggybacking to Enceladus

The latest NASA New Frontiers selection did not select any finalist proposals to Enceladus, which is one of the most promising targets for life in the solar system. It did however select Dragonfly, ...
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Delta-v obtained from Titan by the Cassini spacecraft; just how much of a “gas tank” was it?

In the video Cassini at Titan: A World Unveiled after about 01:56 Linda Spilker, Cassini Project Scientist, Jet Propulsion Laboratory says: Not only was Titan ...
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How is a Russian satellite's behavior “very abnormal”?

The BBC has a news article saying: "Mystery Russian satellite's behaviour raises alarm in US". But the article doesn't say how or why the behavior is "abnormal". And the linked transcript of Remarks ...
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Can the Sun's magnetic field be used to propel a solar satellite?

Can diamagnetic materials or a diamagnetic devise be used to propel using the magnetic field of the Sun in a solar polar magnetic assisted slingshot?
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What are “Ohms burns” in the context of Scott Kelly, KSP, and the Space Shuttle?

The Ars Technica video Astronaut Scott Kelly teaches orbital mechanics with Kerbal Space Program (also in YouTube) is a little bit humorous. When Scott Kelley is talking about orbit circularization ...
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How rare is it in the 21st century to use five stages to get to LEO, especially for a low-mass payload?

@BobJacobsen's comment about the MX Missile (and protests) in the 1980's got me clicking in Wikipedia, which led me to the Minotaur IV launches, the most recent of which seems to be ORS-5 or "...
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Was anything special done for the Cygnus OA-9 launch to give it so much extra fuel?

The Cygnus OA-9 mission has had plenty of extra fuel to burn! While docked at the ISS, it burned for a while to raise the ISS' orbit. This may have been more of a demonstration and token altitude ...
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Spiraling out from circular orbit to escape via low thrust, what is γ (gamma)?

@MarkAdler's comment led me to ask Why would a slow spiral from a C3 of zero take about 2.4 times as much ΔV as an impulsive maneuver? which resulted in this tidy and efficient @MarkAdler answer which ...
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Why would a slow spiral from a C3 of zero take about 2.4 times as much ΔV as an impulsive maneuver?

I just read a fascinating comment that I don't understand. In part it says ...the Oberth effect does not depend on the mass of the object. A slow spiral in to a low orbit from a C3 of zero will ...
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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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Maneuver to the optimal point of a given orbit

There is a spacecraft on an initial orbit. There is a target orbit. The Keplerian elements are given for the orbits. The problem is: when and what $\Delta V$ to apply to the SC to move it to the ...
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What is Tiangong-2 doing?

Some news in various outlets following some twitterings including this tweet by Jonathan McDowell about Tiangong-2 performing a sizeable orbit-lowering, followed by a re-raising: ‏ OK now that's ...
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Largest delta-v from mechanically stored energy?

The math behind this answer suggests that while the delta-v delivered from hand-throwing an object from the ISS would not produce prompt de-orbit and atmospheric reentry, it would still lower the ...
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Orbital change to reach specific earthly location with constrained dV

If I have an orbit (in this case, a non-eccentric orbit) and, at a specific point in time, need to find a maneuver to cause reentry in a specific point as quickly as possible with a delta-V limit (if ...
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Can/Will the James Webb Telescope maintain its position passively?

A recent article about the telescope states (emphasis mine): Unlike Hubble, which orbits the Earth at about 340 miles of altitude, Webb will be sent almost a million miles into space, at a ...
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Space model transfer to moon displacement [closed]

I'm having a problem with the insertion from a LEO orbit into a moon orbit/ moon flyby in my gravity simulator. I use the calculations listed below. I think it is due to the fact that the moon pulls ...
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Any news of TESS' lunar flyby; how well did go?

According to this TESS tweet: TESS is on track for a lunar flyby on 17 May at 06:34:35 UTC (2:34 AM EST). At this point, TESS will be 8,253 km from the lunar surface. In the coming days, follow @...
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How to intuitively explain that reaching geostationary orbits consume more Delta V than escape orbits?

Studying again orbital maneuvers, I found the following plotting the cost of a Hohmman transfer between coplanar circular orbits (black line), in terms of $\Delta V$ against the orbit ratio $r_f/r_i$. ...
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What is the difference between dual-spin spacecraft and hybrid(attitude control) spacecraft?

The definition from this source is "Two classes of spacecraft bring together the advantages of having momentum bias and yet provide a non-spinning base for accommodation of payload elements and ...
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Can someone give me a 'trajectory optimisation for dummies' answer?

So, I am currently doing a project on trajectory optimisation. I get the principle of it, minimise fuel cost for a journey, or try to maximise the spacecraft weight at target destination, and that ...
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Can bad satellites be pulled out of orbit with an Orbital Mass Accelerator? [closed]

Could an Orbital Mass Accelerator OMA be used to knock other satellites out of orbit? Leaping from satellite to satellite using a magnetic field to accelerate some useless satellites and decelerate ...
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How to calculate a transfer orbit

I'm starting to study by myself orbital mechanics, but I don't understand well how can be calculated the transfer orbit. If I have for example a route Earth-Jupiter, how can I calculate it? I've read ...
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Was SpaceX's launch of Formosat-5 more vertical than normal for any particular reason?

Reading both the abstract and the plain language summary of the recent paper published in the journal Space Weather Gigantic Circular Shock Acoustic Waves in the Ionosphere Triggered by the Launch of ...
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What do the terms milli-g and microgravity mean? How are they used?

I've seen the terms "milli-g" acceleration and microgravity in many questions and answers here, within the context of spaceflight. Does milli-g refer to accelerations between 0.001 $g_0$ and 1 $g_0$, ...
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Insight mission broken-plane maneuver needed?

Will the Insight cruise stage do a broken-plane maneuver at TCM-2 (or 3), or does the Centaur upper stage have plenty of performance (as I suspect) to directly insert this small s/c into the necessary ...
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What would be the minimum energy trajectory for an inbound intercept course for another body?

Let's say that you have a body inbound to Earth, and you've got plenty of time before it is within range. But you want to intercept it at minimum relative velocity, e.g., you're going to land on it or ...
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What would be the effect of a non-periapsis and non-apoapsis prograde burn on the shape of an objects orbit?

Pretty new to orbital mechanics and this question has been bugging me. How would the shape of the orbit be affected by a prograde burn at a location that isn't the periapsis or apoapsis ? For example ...
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What will the heat shield on the BFS be made of

Musk has stated that the BFS will need a heat shield capable of reentering the atmosphere from interplanetary trajectories. So I take it the ship will come in directly from the transfer trajectory and ...
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Would a Mars flyby be possible on a transfer orbit from Saturn's moon of Titan to Earth?

So, I am trying to calculate whether a transfer burn from Saturn's moon of Titan to Earth would involve a Mars flyby, assuming I have the burn start on 2 March, 2025 and arrival on 19 March, 2031. ...
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How do I calculate the delta-v with patched conics?

I am trying to calculate the delta-v between Kerbin and Duna from a 70 km circular orbit around Kerbin just to do a flyby of Duna. However, I am running into a couple of difficulties with my ...
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Improvements to script for Finite Burn Trajectory Optimization with MATLAB

I've written a MATLAB script to use the bvp4c two point boundary equation solver to implement a Calculus of Variations trajectory optimization of the problem of a single finite burn with a free coast ...
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How do multiple satellites deployed in the same launch reach their different final orbits?

For example on the Iridium-4 launch from SpaceX on 22-12-2017, 10 satellites are deployed almost at the same time. How do the satellites go into their own separate orbits after they are deployed? When ...
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Specific kind of orbital transfer?

What do you call the kind of transfer that takes an orbiting body from orbiting the planet of the system to orbiting a moon of the system. I am merely looking for the name of this kind of transfer ...
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Why are electrodynamic tethers not used to propel payloads beyond LEO?

Bringing spacecraft to higher orbits than LEO is quite expensive and as rocket reusability gains traction, it will probably get even more expensive when compared to a standard LEO deployment since the ...
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Best time to perform an orbital inclination change — during ascent, or once in circular LEO?

Given that the $\Delta V$ required to perform an orbital inclination change is proportional to velocity, I was wondering when the best time to perform such a maneuver would be. Would it be best to ...
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Apollo 11 CSM spacecraft orbit

How long would it take to orbit the earth at a medium altitude (with equation). I need a equation that would help me figure out how long it would take to orbit at that altitude.
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What happens to JWST after it runs out of propellant?

JWST will be orbiting L2 which is unstable equilibrium thus will require propellant for station keeping. JWST will carry propellant for 5-10 years. What will happen once it runs out of propellant? ...
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Design of an elliptical transfer orbit

I was working an example in Charles Brown's "Elements of Spacecraft Design" but I can not figure out how the Time of Flight was calculated. Here is the problem Example 6.5. I got the correct answer ...
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Fuel-optimal thrust profile for an orbital ascent on a planet with an atmosphere

This is a continuation of a previous question posted a few months ago. If we consider a SSTO vehicle launching from a planet with an atmosphere, would it be fuel optimal to have a period of lowered ...
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Traveling in a circle while in orbit

What is required for a satellite to remain positioned 400 km above the north pole, thus allowing it to appear essentially stationary relative to the surface of the earth? Could this best be achieved ...
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Injection versus insertion

I've noticed that maneuvers to leave a body's sphere of influence on the way to another body are invariably referred to as injection maneuvers, for instance, translunar injection, while maneuvers to ...
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Lowest delta-v maneuver to reverse the direction of a satellite in LEO?

Part of this answer was inspired if I remember correctly from a question about how to reverse the direction of a satellite in LEO with the minimum delta-v. Whether this was the original question or ...
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What inclination change could the 5th stage Orion 38 motor provide ORS-5 (SensorSat)?

The screen shot and block quote below are from Oribal ATK's Mission Update: Minotaur IV ORS-5 Launch. ORS-5 or "SensorSat" is a technology demonstration for a class of satellites that will sit in LEO ...
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Where can I find this Space Shuttle Memo?

T. J. Fill, “PEG Prediction Corrections,” Shuttle Memo 10E-80-11, The Charles Stark Draper Laboratory, Inc., Cambridge, MA, March 1980. And this isn't a request to violate copyright, if that's an ...
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How to optimize time of ignition for an on-orbit burn and/or coast phase on ascent?

I've been playing around linear tangent based guidance laws (specifically the old Atlas-Centaur Surveyor guidance, Apollo IGM and Space Shuttle PEG code) and while PEG has an option for a coast phase ...