Questions tagged [orbital-mechanics]
Orbital mechanics (also called astrodynamics) is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft on an orbital or escape trajectory. For the movements of celestial bodies, use [celestial-mechanics], not this.
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sun pointing coordinate system design
I am trying to program slew maneuver procedure for a spacecraft. My goal is to define a target coordinate system that is aligned with sun vector so that the spacecraft can slew its attitude to always ...
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NASA’s NIAC has awarded phase III funding for Diffractive Solar Sails. Demonstration mission in the works?
Diffractive lightsails use small gratings embedded in thin films to produce diffraction (which causes light to spread out when it passes through a narrow opening).
Diffractive light sails are a ...
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Object slowest at periapsis - despite correct position calculation
I'm coding up a simulation of celestial bodies using patched conics. At the moment I'm stuck with calculating the velocity of the object in the perifocal frame.
For the position I'm simply using the ...
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Eclipse/sunlight detection for LEO satellites
I am trying to use poliastro to obtain the positions of the propagated spacecraft and the lighting conditions at each position.
The documentation in poliastro page shows an example of the shadow ...
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In circle orbit, give a delta V to a satellite, how to find final orbit altitude?
I think this is a very very simple question for me, but unfortunately I cant solve it...
A satellite is orbiting in a circular path at an altitude of 600
kilometers. If the satellite is capable of ...
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Is there any data for space debris that I can use to develop an AI model to predict the orbital decay time?
I need to develop a model to predict the orbital decay time for my graduation project but I searched for data that can help in that project and I failed to obtain such data.
Can any one suggest a ...
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ECI position and velocity from angular velocity
I need help with an orbital mechanics issue that I cannot figure out.
I have the initial ECI position and velocity ($r_{vec},v_{vec}$) of a certain satellite. Through them, the angular velocity, the ...
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Earth re-entry from orbit by a sequence of upper-atmosphere dips to reduce kinetic energy?
There are quite a few questions on this sort of theme here, and I've also read one or two other things, like non-ballistic re-entry. So this might be a duplicate, but I don't think so.
To clarify: I'm ...
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Converting Keplerian Orbital Elements into 2D State Vectors in Unity C#
I have done an extensive amount of research into this topic, but am really struggling to implement the math necessary to pull this off correctly.
Just for some context: I'm trying to create a semi-...
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Definition of "stable orbit"
I often struggle with the term "stable orbit" for objects in earths sphere of influence, since all real orbits are affected by disturbing forces.
Sentences like:
It is not possible to ...
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How I can find the angular orbital velocity of satellite in circle orbit?
I know that we have the angular orbital velocity of a satellite in circle orbit as $w_0=\frac{v}{r}$, but I want another way to find out the angular orbital velocity of a satellite in the circle orbit....
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What assumptions were made about the sphericity of the Moon for the Apollo program?
I've just been reading about the Apollo program.
Apollo 8 seems to have gone into a fairly circular lunar orbit 69 miles at perigee.
Apollo 10 was pretty much similar, although they dipped down with ...
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Gibbs' method and position vectors' reference frame
As mentioned on this website https://www.studeersnel.nl/nl/document/technische-universiteit-delft/flight-orbital-mechanics-and-propulsion/chapter-05-preliminary-orbit-determination/4604099, we need to ...
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When you burn retrograde, will you reach periapsis sooner or later?
Say you have two spacecraft in identical orbits. Say at a point after apoapsis and before periapsis one of the spacecraft burns retrograde to lower its periapsis, and the other spacecraft does nothing ...
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Satellite Surface Temperature in Orbit
I am trying to calculate the satellite surface temperature in Orbit for Thermal Tests of our satellite.
Referring "Space Vehicle Design, D.Griffin, Ch.9, the equations of heat transfer on the ...
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How often does a CubeSat leverage its ADCS?
I'm wondering how often an Earth observation-focused CubeSat (6U - 27U) would leverage its onboard Attitude Determination and Control System (ADCS).
Would it be employing its ADCS to optimize every ...
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Earth to Enceladus [closed]
Sci-fi writer needs to get from Lunar Orbit to Enceladus Orbit in least amount of time with a travel acceleration of 1.5G no more than 3G for navigation changes.
What resources are available that I ...
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Difference Result of Numerical Satellite Propagator
Currently, I am trying to build a numerical propagator platform for satellite that accommodates for all kinds of perturbation. So, for validation purpose, I compare the result of my own program and ...
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Eccentricity Vector as a function of position only, as seen on Wikipedia?
I am looking into some Lambert's solver-type research and came across this wonderful formula on Wikipedia at the bottom of the Lambert's Solver page, here. It has a parameterization gamma, a normal ...
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Why Euclid's orbit is not like Gaia but like JWST?
Euclid, Gaia and JWST are all orbiting Lagrange Point L2. Why is Euclid's orbit similar to JWST but not Gaia's, why is Gaia's orbit different than Euclid and JWST ?
Orbits are shown here for example:
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How can systems of skyhooks help interplanetary travel
I recently watched a kurzgesagt video on skyhooks, and it mentions that a system of skyhook, one on Mars and one on Earth, can shorten a trip to Mars from 7-9 months to 3-5 months. I am confused on ...
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What is the optimal planetary sunshade arrangement?
To cool a planet down, one may place a sunshade between the planet and the Sun.
On its own, this is not stable due to radiation pressure, so a simple scheme like a big circular piece of aluminium foil ...
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Perifocal to ECI using Argument of Latitude
Suppose a satellite is orbiting Earth in a circular orbit.
I know the following orbital elements:
Inclination i,
RAAN (Ω),
Semi-major axis a (or orbit radius given that it is a circular orbit)
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How to calculate physics of interplanetary transit?
Please note, I know nothing about space technology but am interested in how this works and possibly in writing a simulator for it, so a basic answer, with some links to further math is what I'm ...
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Calculate velocity vector of elliptical orbit given the position vector at that point, the instantaneous speed, the true anomaly, and the inclination?
Sorry if this is obvious, but I am an amateur at orbital mechanics and trigonometry was never my strong suit. I would like to calculate the velocity vector at a point in an orbit given:
position ...
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(In ECI) How can I compute the RAAN of an orbit given the eccentricity vector, the declination of the orbiter at apoapsis, and the inclination?
I am working on a personal project, and I want to write a program to obtain the RAAN given the angle of the eccentricity vector to the X-axis (ECI) along the XY plane, the declination (angle from XY ...
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How feasible would this mission to Proxima Centauri be?
This is a scenario that I have recently made up: A spacecraft is at the edge of the solar system, in orbit around Pluto, to make its journey to Alpha Centauri. The spacecraft wouldn't accelerate from ...
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How could a spacecraft reduce an orbital insertion burn after a Hohmann transfer using gravity assists?
I want to calculate a mission to Saturn, and my theoretical spacecraft has a total Delta-V of about 10,000 m/s. I have seen using different tools that it will take about 6000 m/s for the initial ...
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How do I calculate the maximum northern and southern latitude a LEO satellite can image?
How do I calculate the maximum northern and southern latitude a LEO satellite can image? What parameters would I need?
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What is the difference between these two Universal Gravitational Constants? [closed]
Can someone please help understand when to use each of these Universal Gravitational Constants.
G = 6.67 x 10-11 N•m2/kg2
G = 6.67 x (10^(–11)) N(m^2) (kg^(2))
compared to
G = 6.67 * 10-11 m3/kg-1s-2
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ISS (ZARYA) TLE to Latitude Longitude Conversion
I am trying to take TLE of ISS (ZARYA) and get the latitude longitude and height. I am aware the TLE is in TEME~(True Equator Mean Equinox) frame. This means that the TLE was generated considering the ...
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Orbit prediction for satellites using the Kepler model
I would like to know how to model the motion of satellites in orbit using Keplerian, i.e. develop a simulation model that tracks paths of satellites using Keplerian orbits in Python?
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What's the motion of two connected satellites orbiting the Earth after their separation?
Let's consider the following problem (it's a job interview question): two satellites are orbiting the Earth in a circular orbit; they are rigidly linked by a tether which is always pointing in the ...
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Which notes and/or books on mathematics, physics, 3D geometry preparatory to the study of orbital dynamics?
I have a master's degree in aerospace engineering and I'm preparing for job interviews for orbital mechanics/space flight dynamics engineer positions and I need material about maths, physics, 3D ...
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Can electrodynamic tether propulsion use the solar magnetic field?
Electrodynamic tethers have been proposed for satellite propulsion in the magnetic fields of Earth and the Gas Giant planets.
Is it realistic to consider using the Sun's magnetic field for ...
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How do you calculate the characteristics of an orbit of an object launched from a mass driver?
What formula can I use to calculate the apoapsis of the orbit of an object launched from a mass driver on the moon at a given speed and angle to the surface (angle from horizontal)? The device will ...
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How do we define the aphelion of Earth?
After seeing this question, I was curious on how we define the aphelion of Earth. On a quick search it said that the aphelion is the point when Earth is the furthest way from the sun. However, all the ...
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Moving target during rendezvous
I am currently studying rendezvous and docking. I noticed the elliptic Hill equations only consider the acceleration of the target satellite due to its elliptic orbit (and fictitious forces in LVLH ...
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Will this homopolar motor self rotate in a vacuum?
Is it convenient to ask about the motor from the link:
Roller Homopolar Motor
When it is on the table, the motor rotates freely, together with the attached conductor.
Will the upper motor in the ...
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Finding or calculating orbital velocities of celestial bodies at periapsis/apoapsis?
I'm writing a solar system simulation that uses n-body physics. To plug in the celestial bodies in our solar system, I'm copying orbital values from wikipedia. For one example, the wikipedia page for ...
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Distance from earth to another planet in solar system
Initially I thought that the problem is trivial, but it turned out to be something relatively complex. I found no one place that would answer the question directly nor a quick guide showing what ...
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Calculate position of planet on fictitious orbit each day
I'm a software developer but my degree with in mathematics. I'm trying to develop a game/simulation of a fictitious randomly generated solar system, and trying to work out how to model and calculate ...
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TEME state vector to TLE orbital elements
I was looking at time series of some TLE parameter(semimajor axis, inclination, etc..) and I wanted to how those parameters evolve between measured time points.
So i decided to feed TLE element to ...
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What causes a satellite's orbit to decay?
Why do orbits of satellites orbiting at sufficient speed, far beyond the Earth's atmosphere, decay if there is no atmospheric drag? What drag is applied on the satellites at that altitude?
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Approach to Interplanetary Transfers in GMAT
I hope to find a straightforward process for designing interplanetary missions using the General Mission Analysis Tool (GMAT). This would involve calculating the required initial state, timing, and ...
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How close do gravitational 2-body hierarchy levels get?
Due to very few 3-body arrangements being stable (this question thus excluding co-orbital objects like trojans), objects in space usually arrange themselves in a hierarchy of 2-body systems. When the ...
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Is it possible to create an analytical ephemeris from raw position and velocity of a Body?
I would like to have an analytical ephemeris for various bodies of the solar system (planets, natural satellites and asteroid). I have at my disposition spice kernels from which i can extract position ...
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How did theorists determine that the atmosphere attenuates enough to support unpowered orbits?
Before getting rockets into space were scientists certain that the density of the earth's atmosphere would decrease with height enough to permit low earth orbits? If so how was that determined?
(If ...
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Could a “solar gravitational synchrotron ” use solar thermal rockets to "powerslide" spacecraft out of the solar system?
Could a “solar gravitational synchrotron ” use solar thermal steam rockets to launch spacecraft out of the solar system?
Solar thermal steam rockets https://en.wikipedia.org/wiki/Steam_rocket have ...
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Negative elevation angle
What does it mean to have negative values of elevation angle from the low-Earth orbiting (LEO) satellite? Can the negative values of elevation angle be useful?
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