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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Different results for Orbital Period?

I am making a hypothetical solar system with random masses and distances (but still physically and mathematically accurate). I want to calculate the trajectory of a spacecraft, and to do that, I need ...
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How does the flight computer work on a rocket? [closed]

My rocket has a target, an orbit 300 km high, my flight computer has 2 sensors, the MS5611 and the BNO055. Use these 2 to receive the delta-state, Once I have the delta state, how do I tell my rocket ...
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What space simulators are the most accurate at simulating real world physics?

We've all at least heard of KSP, a popular space flight simulator. its not the best but can teach someone the basics at rocket science, delta V, burntime, basic orbital maneuvers, retrograde, prograde,...
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How to get lunar L, B, C parameters from the Python package Skyfield?

Answers to What are the “Moon L, B, C” angles shown in this solar eclipse simulation? explain that L and B (or "l" and "b") are the "selenographic coordinates of the Moon's apparent center" (latitude ...
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Aldrin cycler mission to Mars in MATLAB [closed]

I am planning to do a mission project on Aldrin Cycler (Earth to Mars) in MATLAB. Can you please suggest me where to start. I tried reading few research paper related to this topic, any other advice?
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Is a polar geosynchronous orbit described by Viviani's curve?

This answer to Is there a name for the great circle where latitude and longitude are equal? says (in part): More generally, a clélie is the name given to any spherical curve where the longitude $\...
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Locations of the terminator on Mars' surface on 1976-07-24T10:35:26Z?

How can I find points of latitude and longitude on Mars that fall on the terminator (day/night line) on a specific date, for example 1976-07-24T10:35:26Z as ...
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Angles only Orbit Determination for LEO satellites

I have a script that uses the Gauss method for Prilimanry Orbit determination of satellites using 3 sets of ra-dec and the corresponding LST (adapted from the MatLab example given in the appendix of ...
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Is it possible to be totally stationary in space?

In lots of science fiction movies, spaceships are shown stationary, but don't they have to be in an orbit? Is it possible to not be moving and not orbiting anything, or is this totally impossible?
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Earth Moon Pork chop plot

Does pork-chop plots exist for Earth-Moon System? I could only find pork-chop plots for Earth-planet systems.Could someone please shed some light on this topic?
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Why does this formula for the required delta v of a semi major axis alteration not work or am I I misinterpreting it?

My spaceflight mechanics lecture script has this formula, without derivation or reference. But I think it does not work. For example let us assume we find ourself in a circular 250km orbit around ...
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What are the choices today for orbital mechanics simulation software?

I used to be familiar with the various choices out there for orbital mechanics simulation software. Alas, those days are gone. What are the choices today, preferably sorted by platform? This ...
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Differences between Semi Major Axes and ECF Magnitudes for Circular Orbits with J2 Perturbation

I have simulated (in STK) a satellite at near circular orbit, near-equator, with Brouwer Lyddane Mean Long SMA of 6935.31km, inclination 10 degrees, and eccentricity of 0.0001875 (these are solved-for ...
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What is the acceleration necessary for a Brachistochrone transfer from Earth to Mars?

With these orbital configurations, source-Bing leaving Earth on Aug 16, 2106 and arriving on Mars October 10,2106, what is the lowest continuously-applied acceleration that can make what is ...
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Why do we prefer using the rotating reference frame rather than the Inertial frame in the three-body problem?

As the title says, I wanted to ask why do we prefer using the rotating reference frame rather than the Inertial frame in the three-body problem to place the primaries? And how is it better for ...
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How will NASA's TROPICS cubesats be inserted into their three orbital planes and proper phasings?

Rocket to launch 8 cubesat to LEO at an equidistant distance reminded me that I'd never asked this question. NASA's TROPICS 3U cubesat constellation hasn't been launched yet, so there's still time to ...
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Brachistochrone variation for Earth-to-Mars Orbit

Wouldn't a Brachistochrone curve to Mars orbit be a much faster and more efficient way to send personnel and equipment to mars as compared to the Hohmann transfer if we used an Ion engine? The below ...
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Can L3 have halo orbits?

I've recently said you see one co-linear libration point, you seen 'em all. That's what I always say and while halo and other orbits associated with Sun-Earth L1 and L2 work similarly, L3 is 2 AU ...
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How much harder would space exploration be if the Earth rotated like Uranus does?

Let's say the Earth got knocked a bit silly in the distant past and somehow space-loving life evolved on this planet. They roll around on an Earth with an axial tilt of 98°. How much harder is it for ...
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2D Orbital Path from State Vectors

Given a planet of mass $M$ at the origin, and the state vectors $\textbf{r}$ (in meters) and $\textbf{v}$ (in $m/s$) at time $t = 0$ for a satellite, what are are the equations for: Distance $d(t)$ ...
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Why do orbits in the Iridium constellation have an inclination of 86.4°?

Wikipedia's Iridium_satellite constellation; In-orbit spares says that Iridium satellites have an inclination of 86.4°: Significant orbital inclination changes are normally very fuel-intensive, but ...
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Interpolating precise ephemerides of GPS satellites

My objective is to obtain at least a sub-meter position accuracy by interpolation of the GPS ephemerides. There is conflicting research outside, where some authors state that a simple Lagrange or ...
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How does a butterfly orbit move in 3D? Way to generate or visualize?

The paper Earth-Moon Near Rectilinear Halo and Butterfly Orbits for Lunar Surface Exploration (AAS 18-406) says Periodic Orbits in the Earth-Moon System The current investigation focuses on ...
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Could a horseshoe magnet help a satellite stay in orbit?

If a horseshoe magnet was attached to a satellite orbiting the Earth, would the interaction of the Earth's magnetic field and the horseshoe magnet's magnetic field result in the magnet being propelled ...
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Chase orbit questions

So my google-fu is failing me so I'm hoping someone can help out here. I've been reading up on chase orbits and how things like the Shuttle, dragon, etc all approach the ISS and I understand the ...
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Python Libraries: Numerical Propagators and Access Calculations

I have written some of my own code in Matlab that performs two body unperturbed as well as J2 perturbed orbit propagation. I am shifting to a new environment that requires the use of Python, and can't ...
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Where can I find data on satellite orbits?

I'm an enthusiast who'd like access to satellite orbital data to simulate / plot trajectories of manmade satellites (of any kind) on my home computer. Where's the best place for me to find this kind ...
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Are hyperbolic trigonometric functions used to calculate hyperbolic orbits?

The following comment is really intriguing! I would say, "Yes, The equations for going from Mean Anomaly to Eccentric Anomaly to True Anomaly are indeed different for hyperbolic orbits than for ...
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Issue with the Gauss problem for solving interplanetary trajectories

Blue is Earth, Red is Mars, Orange is Jupiter and all the whites are Earth to Mars trajectories. The odd trajectory lines in the middle are the problem I'm trying to solve. As you can see in the ...
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Equation for orbital period around oblate bodies, based on J2?

In this answer I point out that the period of items (ring particles, moons, spacecraft, etc.) around an oblate body will not scale exactly as $a^{3/2}$ because the closer you are to the planet, the ...
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Does the elliptical orbit have many periapsis points?

If I have the position and velocity vectors of a satellite in an elliptical orbit for one point in time, then I can know its position in its orbit at any other time, and with that I can calculate the ...
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How did the Lunar Module dock with the rest of Apollo 11 and what is the “CSM”?

I'd like to ask if anyone can, in layman's terms, describe the procedure by which the Apollo 11 astronauts were able to get back to their ship? I ask because the most accessible literature on this ...
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Balancing a mirror

A possible way of heating up Mars is to use mirrors to direct more sunlight towards the planet. I am not asking about the feasibility or cost of such a gigantic project, but I have a question ...
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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 ...
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How to determine the distance between where Earth and Mars are two specific dates?

How would I find the solar-system-relative distance between where Earth would be on 2106/8/16 and where Mars would be on 2106/10/16, or any combination of dates. Image source-Bing Is there software ...
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Does it even make sense to talk about Mercury's triangular libration points (L4, L5)?

The recent question How much radiation shielding would be required for a habitat at Mercury–Sun L5? got me thinking. There are a large number of disadvantages and challenges to building or putting a ...
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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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Atmospheric reentry drag and friction

What is the difference of air drag in ground level with let say moderate speeds like fast cars 200km/h to 400km/h with high speed vehicle reentry at high altitude where the air is so rarified. Making ...
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Do all dangerous asteroids first pass through keyholes?

Scitech Daily's MIT Engineers Devise the Best Way to Deflect an Incoming Planet-Killer Asteroid Now MIT researchers have devised a framework for deciding which type of mission would be most ...
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Calculating trajectories of payload fairings

How can I calculate the trajectory of a payload fairing assuming that I have several data points of height or speed of rocket? I'd like to know which topics are necessary to study this.
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Why does Earth not appear to be at the focus of TESS' elliptical orbit in this video?

An excellent review of all of the considerations and work that has gone into designing TESS' orbit can be read in the ArXiv preprint A High Earth, Lunar Resonant Orbit for Lower Cost Space Science ...
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Does the shape of Cruithne's orbit change within one period?

The question Why not explore Cruithne? includes the GIF below. I've extracted two frames and extracted the red pixels of Cruithne's orbit where ...
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Would a space rocket launching from Ceres in a path to Jupiter be faster relatively to the sun than one launching from Earth?

Suppose you have a space rocket which when launching from Earth its speed relatively to Earth it's 11 km/s. For what I've read in another topic in Space SE, the orbital velocity of the planet where a ...
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How do two-line element sets handle rev numbers > 99,999?

In a two-line element set (TLE), five characters in line 2 -- columns 64-68 -- are for the rev number. (https://en.wikipedia.org/wiki/Two-line_element_set) But some satellites have been around the ...
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Why does TDRS 1's inclination evolve so much differently than that of all the others starting in 1995?

The plot below is from the question Why do the geosynchronous TDRS satellites have this distribution of inclinations?, and the explanation says Inclination and mean motion (rev/day) for TDRS ...
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How does accelerating a spacecraft at the apogee affect its orbit?

I was reading an article about the Oberth effect. It describes the orbital maneuver. The article said that the spacecraft performs a burn at perigee and gets into higher orbit. So the question is "...
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How does the dynamics of the Jupiter and Saturn system make them be well suited for low-energy transfer?

Many papers mention that the compact and complex dynamics of the Jupiter and Saturn systems makes them ideal low energy transfer. My question is how? How does the dynamics of the Jupiter and Saturn ...
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How to estimate which astronaut ends up furthest from the ISS after one orbit?

Three astronauts; Goofus, Gallant and Zippy the Pinhead play a game. All three take their cold gas thruster-powered jet packs and quickly move 100 meters away from the ISS. For some reason after ...
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How to calculate delta v for orbit change around body; not necessarily Earth?

Let me express my joy at having found this great place of Stack Exchange. My question concerns the calculation of delta v requirements when already in orbit around a body and lowering or raising ...
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Analytical treatment of relative positions between satellites?

I have been searching the internet for estimation of relative position between two satellites. However, all sources seem to be pointing to methods used for proximity operations, where the math ...

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