# Questions tagged [orbital-maneuver]

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

216 questions
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### Oberth effect for Earth vehicles

I don't understand this and must ask a probably very stoopid question here: The Oberth effect says that a rocket is much more efficient when (and in the orbital direction of) a payload when it ...
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### Transfer between circular orbits in up to 5 maneuvers

There are 2 circular orbits with different inclination and RAAN. I have to transfer from a specific point (true anomaly given) of one orbit to a given point of another in 1 month. The period of the ...
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### Can someone help Scott Manley explain this Snoopy-capturing maneuver?

In his recent video Apollo 10's Lunar Module Snoopy Is Lost In Space - Could We Bring it Home? Scott Manley uses some fancy supplemental techniques in KSP to simulate and explain a possible mission to ...
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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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### What is the largest delta-v ever produced in space 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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### On the dynamics of two connected objects located at different circular orbits

I'm just thinking about the qualitative and quantitative implications of a hypothetical orbital problem, but what I ended up does not make sense as it should. In particular, assume that two objects ...
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### How often are satellites in GEO moved to follow customer demand?

The BBC News article Inmarsat lays big satellite order with Airbus says: The firm is buying three new spacecraft to augment its Global Xpress system, which provides connectivity to on-the-move and ...
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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 for different orbits. Obviously, there still is some residual air resistance that decreases as the orbital ...
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### How do I calculate the change in the argument of periapsis after a plane change maneuver?

Let's say I have a spacecraft in an initial geocentric orbit with the following parameters: a = 7,960,000 m, e = 0.010, $\Omega$ = 180$^{\circ}$, i = 98$^{\circ}$, $\omega$ = 90$^{\circ}$, $\theta_0$ =...
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### Using the distance components to calculate minimal dV randezvouz trajectory

The are objects on 100 circular orbits, 1 object on each orbit. One orbit is said to be initial (I) and others are final (F) . ...
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### Determine the “nearest” orbit

There are 100 circular orbits with different radii, inclinations and RAAN. The nearest orbit by definition is the one, which requires less $\Delta V$ for a transfer. Assumed that 2 impulsive ...
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### Multiple revolution Lambert problem

The Lambert problem solution determines the $\Delta V$ required to transfer from r1 to r2 in ...
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### Is it OK to spend 3 tons of fuel for the orbit transfer?

There are 2 coplanar orbits (same $i$,$\Omega$,$\omega$): Apogee and perigee on 200km Perigee on 700km, apogee on 8000 km I used the izzo.lambert function from ...
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### Lambert problem solver needed for custom gravity in Python

I need to solve the Lambert problem, however, I have a custom gravity model. My ODE of motion is: ...
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### How will Starlink satellites deploy from the fairing and reach their orbits?

Elon Musk posted this picture of the first 60 Starlink satellites packed densely into the fairing of the Falcon scheduled to launch in a few hours. There doesn't appear to be a launcher or ejector to ...
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### Can the ISS boost maneuver engine be heard by the astronauts on board?

In the extremely cool demonstration video Demonstration of Acceleration Inside the International Space Station During a Reboost ISS Expedition 22 Commander Jeffry Williams says near the end at ...
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### How to find Horizons ephemerides or Spice kernels for the cis-lunar halo orbits of the Themis B & C) spacecraft?

The Themis spacecraft B and C have been renamed ARTEMIS P1 and P2 and moved around in cis-lunar space from Earth orbit to Lunar orbit. This transfer involved libration point orbits, as discussed in ...
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### What if GOCE rolled 90°?

Reading this question: Is GOCE a satellite or aircraft? I wondered what would happen if GOCE rolled 90° in either direction, so that it's solar panels become parallel to Earth's horizon, and then ...
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### How to find the transfer orbit from a initial circular orbit to a final elliptical orbit

Is a hohmann transfer or bi-elliptical transfer more efficient for this case? How can I find the transfer orbit that conserves the most deltaV? I will be going from a circular Earth centered orbit ...
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### Minor query on mid course correction and cryogenic oxygen tank incident in Apollo 13 flight path

In the flight path of Apollo 13 (data taken from Wikipedia), the first mid course correction was done at 30:40:50 and cryogenic oxygen tank incident occurred at 55:54:53. I have three small questions ...
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### Is the analysis of this maneuver correct?

Can someone out there help explain (guide, give examples etc.), or show a solution of, the following textbook problem that I can't manage to solve? You’ve just completed an analysis of where the ...
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### How are retrograde orbits attained?

If a satellite is to be inserted into a retrograde orbit (opposite to Earth rotation direction) is it accelerated straight in the desired "westwards" direction until (after overcoming Earth rotation ...
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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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### Could a satellite in GEO-orbit make an evasive maneuver to avoid an anti-satellite impactor?

Communication satellites orbit at an altitude a couple of hundred times above the satellite that the Indian government recently shot down. Also GPS-satellites are about one hundred times further up ...
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### What is the smallest body in which a sling shot maneuver can be performed?

This question asks about the smallest sling shot maneuver performed. What was the smallest intentional, acknowledged slingshot maneuver? I'm asking how small of an object be to perform a sling shot ...
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### Rendezvouses in halo or lissajous orbits

If a spacecraft was in an EM-L2 halo/lissajous orbit, and another craft would was going to approach EM-L2 a few days later, could they rendezvous immediately or is there a limitation when the second ...
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### What was the smallest intentional, acknowledged slingshot maneuver?

I'll keep it short but please read through! Gravitation's $1/r$ potential means everything in the solar system is pulling on everything all the time. Gravitational slingshot maneuvers are normally ...
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### Fastest orbit transfer constrained by maximum g-force magnitude

Let's consider an imaginary constant 1g rocket from Earth to Mars. What is the fastest possible trajectory? Intuitively it seems that the fastest travel time is achieved with the "radial" trajectory (...
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### ISS location identification; estimate size and direction of astronaut acceleration puzzler

note: This question addresses the same video and phenomenon described in this answer (which I found after posting this) but here I'm asking for an analysis of the trajectories of the test masses (the ...
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### Space Shuttle Orbiter VRCS

I am looking for details on the Space Shuttle Orbiter Vernier Reaction Control System (VRCS), used for fine maneuvers on orbit, such as docking. Wikipedia has very little information on the system. ...
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### How could transfers between SEL1&2 and EML Lagrange points be utilized?

The Earth has 7 Lagrange points nearby since SEL1 and SEL2 (Sun-Earth Lagrange points 1 and 2, respectively) are only between 3 and 5 LD (lunar distances) away from the five EML (Earth-Moon Lagrange) ...
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### Orbit class or library or functions [closed]

I am (like a hundred other people, like a thousand other people) trying to make a space flight simulator. I'm not a student. (That said, I found Orbit – space flight sim. It’s excellent.* You ...
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### What's the lowest altitude that an ion engine has been used for a significant orbital maneuver?

I'm thinking about trying to calculate something for Where do ion propulsion's ions go? Do they remain in the solar system or shoot out into interstellar space? Excluding low altitude tests of ion ...
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### How often has (or how common is it for) the ISS's orbit been propulsive lowered intentionally?

The question Which engine worked the hardest to keep the ISS in orbit? laments the tireless efforts to keep the ISS from falling from the sky by regularly executing propulsive orbit-raising maneuvers. ...
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### How would one calculate the Lunar liftoff thrust required for a spacecraft?

I used the thrust to weight ratio of 2.12 to determine the thrust my spacecraft needs for a lunar liftoff, Apollo Lunar Ascent Stage Thrust to Weight Ratio. Is this a proper way of determining and ...
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### Delta-V chart mathematics

Could someone explain me the mathematics behind the Delta-V charts one can find on internet such as:                 &...
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### What are the practical uses of a state transition matrix?

I am studying different dynamical models of relative motion of satellites. In my work, I've always just used a numerical integrator like RK78 to integrate the cartesian system of equations: \$\dot{r}=...
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### What is the closest intentional separation achieved by two satellites?

I would like to know what is the closest separation achieved by two satellites. Let's restrict it to Non experimental satellites (or else it would be 0) Operational satellites (no collision) Post ...
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### Did the astronauts of Gemini 4 have any realistic rendezvous simulator training of orbital mechanic effects?

Gemini 4 was launched on June 3, 1965. It mission included the first attempt of a rendezvous manoeuvrer in space. The rendezvous test failed. Two years earlier, in June 1963, the Rendezvous Docking ...
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### What would your altitude be after you had achieved escape velocity from the moon?

I have been trying to work out how much ΔV would be required to deorbit a spacecraft after it had achieved escape velocity from the moon but I don't know how to work out what the radius of the orbit ...
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### Use of thrusters for Collision Avoidance Maneuver

I'm building an orbit propagator that gives the position of two satellites at time T. The position are expressed in ECI and after that are being transformed in LVLH frame (as mentioned ECI to LVLH ...
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### How often does ISS require re-boosting to higher orbit?

I know that ISS, being in low Earth orbit, requires regular boosts. But I can't seem to find information on how often does this happen. Is it done during each resupply mission, only during some of ...
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### Help choosing a gravity assist scenario for this problem

The problem stated below is from an assignment I was given. My initial approach involved doing a direct Hohmann Transfer to Saturn. This approach violated the fuel constraints and hence was deemed ...
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### Why does the Apollo-8 Trans-Lunar Injection burn appear to be pulsing in this photo?

This tweet called my attention to The Smithsonian National Air and Space Museum story Photographing Apollo 8's Orbit Toward the Moon. The story is quite an interesting bit of space history and worth a ...
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### How do long range space probes adjust trajectory?

More specifically, after the main launch adjustments have been made using the primary boosters and temporary adjusting propellants how might even the slightest trajectory and orientation corrections ...
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### How does SpaceX's Dragon get to the ISS?

How does SpaceX's Dragon capsule get to the ISS? Does Dragon use the onboard Draco thrusters in order to raise its orbit to the station or does the second stage of the Falcon 9 perform the majority of ...
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### Delta-v to move from GEO to GEO

To move a satellite in geostationary orbit, 166°55′E, to the antipode, 13° 4' 3.2" W, what delta-V would be needed for this to be accomplished? As for time constraints, I do not know what are the ...
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### Can you tack against the sun using a solar sail?

Solar sails are a great, inexpensive way to move out from the sun, if you’re not in a hurry. Ocean going ships are able to tack against the wind, and to move up wind. Could a solar sail gain inbound (...