Questions tagged [orbital-mechanics]

Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft. For the movements of celestial bodies, see [celestial-mechanics].

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Converting data from NASA's Trajectory Browser into state vectors

I've found this super awesome tool, provided by NASA, called Trajectory Browser. I would like to simulate some of the trajectories listed there but can't quite figure out how to convert the trajectory ...
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Space Shuttle Moon Mission? [duplicate]

Theoretically speaking, could the shuttle have performed TLI, LOI, and TEI burns given extra OMS fuel? approximately how much fuel and payload bay space/mass would this take up and might there ...
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Are Lagrangian points associated only with the smaller body?

Diagrams of Lagrangian points I've seen always show the points near the smaller object, following its orbit about the larger one. For instance: from Wikipedia. But in fact the smaller object ...
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How can I calculate the azimuth from an earth station to a satellite

I have computed the ecef coordinates of both the user location on the ground, the satellite's ecef coordinates, as well as other inputs such as altitude, lat, long of both satellite and earth station....
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How accurate can a point in space be determined by the likes of the ICRF?

How accurately could a 3D point in open space (i.e. not on an object), say at an elevation of 30,000m above sea level, be located or modelled using the likes of the International Celestial Reference ...
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305 views

Converting Keplerian coordinates into Latitude and Longitude

Introduction My goal is follow up the title of this question and obtain the Earth coordinates (latitude, longitude) from the keplerian coords ...
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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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How to implement SGP4 C++, satellite propagator?

I would like to ask about how to implement the SGP4 code in C++ by Vallado. How can I implement the libraries that are available in https://celestrak.com/software/vallado-sw.php. I think that are the ...
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Explanation of single-burn trajectories from Lunar surface to Earth surface

I learned of the fine book Soviet Robots in the Solar System from this excellent answer. One chapter in it describes how the Soviets had extreme mass limitations on their lunar sample return vehicle ...
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How to use “patch points” to make a continuous halo orbit?

update: I've found "patch points" mentioned throughout the following papers; it is likely that an answer can be found from these sources. Targeting Cislunar Near Rectilinear Halo Orbits for Human ...
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Is the Gateway's halo orbit bound to Earth? Would the Gateway remain in Earth orbit of the Moon disappeared?

Discussion below this answer involves my feeling that calling halo orbits in very asymmetric systems (e.g. Sun-Earth or Earth-Moon) as orbits around the primary, in 1:1 resonance with the secondary. ...
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Would a standard gravity turn still be the most optimal path to orbit if Earth did not have an atmosphere?

If Earth had no atmosphere, then would a standard gravity turn still be the most optimal path to orbit? Why or why not?
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Reference to understand the notation of orbital charts

To address various orbital evolutions of spacecrafts, some particular orbital charts are taken into account. For example, the following is used to depict how a chaser reaches a target: The only thing ...
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What orbital mechanics toolkits available today are suitable for a real-time simulator?

I'm a software engineer and I've always loved Orbiter (also here). However I feel that it's growing a bit antiquated, and it would be nice to have a more modern, open source, or otherwise hackable ...
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How would off-apsis burn effect the angle and position of new apoapsis

Let's say you have an elliptical orbit, if you burn prograde at the periapsis, you extend the apoapsis by some factor(according to vis-viva equation). But if you burn prograde on somewhere during 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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Where did the Herschel Space Telescope go in 2013?

The Herschel space telescope wins as largest optical telescope mirror in space when "optical" includes far infrared (~55 µm). The Wikipedia article Herschel Space Observatory lists the orbit as ...
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What are the orbital-mechanical advantages of a long (100+ second) sub-orbital coast phase?

This answer to Trajectory to get into orbit says: In most real launches to low Earth orbit, the burn continues from liftoff until orbital insertion, without a coasting phase. Some (like Antares) do ...
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Can we calculate elliptical properties in a spherical coordinate system?

Can we calculate the elliptical properties like the semi-major axis and eccentricity using the state vectors (position and velocity) in the spherical coordinate system? http://www.braeunig.us/space/...
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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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Design of return trajectory from lunar polar orbit to Earth's atmosphere

Given a flight path angle, altitude and velocity at re-entry into the Earth's atmosphere, how do I go about designing the return trajectory from a polar orbit at 17km altitude about the lunar surface ...
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Using Differential Equations to model path of satelite around earth

I am new to GMAT and am hoping to use it to model the path of a Low Earth Orbit satellite around Earth. I am thinking of plotting the path on a plane and using polar coordinates to model the path ...
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279 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 ...
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277 views

How do I calculate re-entry velocity when decaying from a circular orbit?

I am trying to find the velocity of an object during re-entry so that I can calculate the peak heat flux but I'm a bit stuck. I know how to find the velocity of the original, circular orbit (300km) ...
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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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Apollo 15 State Vector recreation

I am trying to get the state vectors for Apollo 15 before, during, and after critical manoevers [sp]. IE TLI, LOI1, LOI2, lunar launch, preocking, postdocking, and TEI. I am a totally newbie at all ...
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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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Getting from LEO to a station in geostationary orbit and docking with it using a Hohmann transfer?

How long would it take for a spacecraft with a mass of 30,000 kg, to go from LEO to reach and match the speed of a space station in geostationary orbit so it could dock with the station, using a ...
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What is the formula for Legendre Polynomials from EGM96 calculated in F447.f program?

The F447.f program is designed to calculate the geoid undulation for EGM96. I'm trying to understand how it accomplish this calculation. I stuck in ...
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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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Which two spacecraft have spent the longest times in libration point orbits? (Lagrange points, Halo, Lissajous, etc.)

Libration point orbit is a general term including halos, Lissajous', and a whole zoo of others associated with Lagrange points in three-body systems. Which two spacecraft has been in such an orbit ...
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Will NASA put astronauts into a polar lunar orbit? If so, how?

The NASA news item New Space Policy Directive Calls for Human Expansion Across Solar System says: New Space Policy Directive Calls for Human Expansion Across Solar System and the administration is ...
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Calculating orbital parameters for given requirements

I'm trying to determine what's the best way to calculate the required orbit for a LEO remote sensing satellite. I understand there exists the trade-off between sensor coverage and sensor accuracy, but ...
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Trouble deriving rectangular components of acceleration of satellite in orbit around Earth with J2 consideration

I am trying to derive the rectangular components of acceleration for a satellite in orbit, with Earth oblateness in consideration, in order to use the RK4 method to find the updated position and ...
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Is there a general relativistic relativistic rocket equation?

I am not to familiar with rocket equations but I know that if you combine special relativity with classical mechanics you get "c" as a speed limit. Basically the closer you get to "c" the more you ...
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is it possible to use earths magnetic field as a energy source while in space?

While in space or on the moon is it possible to use earth existing magnetic field to generate electricity?
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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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Do the velocities of orbital debris have a bias in the direction of Earth's rotation?

Most spacecraft are launched and orbit prograde -- in the same direction that the Earth rotates -- to give a "speed boost" to get to orbital velocity. One would therefore expect that the trajectories ...
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Tacking a solar sail to increase duration of acceleration

Because the utility of a solar sail diminishes the further it travels away from the sun (max. distance ~50 AU), the longer it can stay in closer proximity to the sun the longer it can accelerate. Is ...
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How did Shepard's and Grissom's speeds compare with orbital velocity?

As is often said here and in XKCD, an orbit isn't merely high up... it's also going fast. The first two American astronauts -- Alan Shepard and Gus Grissom -- did indeed get "high up" enough to ...
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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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Coupling satellites already in orbit reduce drag and debris?

How would 2 or more satellites be joined to reduce atmospheric drag? Could a 3rd satellite tow and join 2 or more satellites that are in similar orbits to prevent Kessler syndrome? At the very least ...
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How to generate Chebyshev coefficients to produce an ephemeris file?

I am currently trying to perform the same interpolation that NASA uses to generate their Development Ephemeris files (Chebyshev coefficients). I have a table with position and velocity of the major ...
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GMAT change spacecraft orientation

I wish to know how to change the orientation of a spacecraft via GUI or code in GMAT (http://gmatcentral.org/)? Eg. At apogee, point the spacecraft in particular direction etc. by rotating it etc.
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What is “propulsive passivation” and why will the SpaceX STP-2 mission do it?

The Teslarati article SpaceX’s Falcon Heavy flies a complex mission for the Air Force in launch video discusses the upcoming third Falcon Heavy mission STP-2 and quotes the caption on the linked ...
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Why does this satellite collision debris field look like a big “X”?

This answer to the question Whats the protocol if two satellites collide? shows the image below, and I don't understand the shape. I would have expected two "jets" of debris, each projecting roughly ...
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How do you find the temperature of an orbiting aluminum sheet 10x10 cm

I'm trying to find the temperature of a CubeSat in orbit at 140km. I'm trying to use the Stefan-Boltzmann law but don't know how to incorporate the energy from sunlight. I'm using this as a check for ...
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Where can I find examples of orbital state vectors?

I'm currently trying to write a program that can calculate orbital trajectories. The goal is to take any orbital state vector (position, velocity) and convert it into Keplerian orbital elements, or ...
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Does the arrow in this SOHO trajectory animation point heliocentric prograde, or towards the Sun?

This answer links to this NASA page. The first video shows the two STEREO spacecraft use two and three passes by the Moon to leave Earth orbit and enter into an orbit around the sun. Below is a GIF ...
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How would 2 JWSTs make stereo pictures?

Could 2 JWST be launched in opposite directions to provide stereo vision? Would a stereo picture provide any benefit? https://space.stackexchange.com/a/35402/18879 Related: How will JWST manage ...

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