Questions tagged [simulation]

representation of environment or process in a more accessible form using virtual or physical imitation or analogues, often for the purpose of training or testing, includes both real-world (physical) and numerical techniques.

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1answer
66 views

How would an n-body numerical orbit simulator use hierarchy in its Jacobian?

This question is about techniques to calculate orbits. The Github post On the dynamical stability of Principia's modified Jool system (cited in this answer) says: Principia computes the trajectory of ...
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2answers
173 views

Are Jool's moons' orbits stable?

The fictitious Kerbol system includes ...five planets: Moho, Eve, Kerbin, Duna and Jool; and two dwarf planets: Dres and Eeloo; orbit around it. Kerbol contains 99.97 % of the mass in the Kerbol ...
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1answer
43 views

rocket trajectory simulation in inertial frame, with drag

I created a rocket trajectory simulator and optimizer using the following equations of motion for a non-rotating frame of reference $$\dot{v} = \frac{T \cos \varepsilon - D}{m} - g \sin \gamma$$ $$v \...
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2answers
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Source of Gregorek's popular drag equation in ESTES TR-11?

In the early 1970s, Gerald Gregorek wrote a technical note on drag for ESTES (maker of model rockets and parts from what I gather). The note is still very popular in the model rocket community, and it ...
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0answers
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I want to simulate the antenna pointing error when tracking LEO satellites

I am trying to simulate the antenna pointing error of our antenna when tracking LEO satellites using TLE data. I am using the Skyfield library in python. First I loaded the TLE data from the Celestrak ...
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1answer
107 views

Why shouldn't we illustrate spacecraft trajectories on top of static pseudo-potential surfaces?

Three-body spacecraft orbits1 are regularly discussed here and from time to time someone will include a pseudo-potential plot from Wikipedia in their explanation. The discussion often goes south when ...
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CesiumJS: Hayabusa 2 location w.r.t Earth

Given these coordinates w.r.t Sun: Hayabusa: x = 86014493 y = 112689997 z = 54295960 Earth: x = 82241037 y = 112748971 z = 48876281 How do I calculate Hayabusa coordinates w.r.t Earth center? I ...
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2answers
93 views

Modelling a circularizing burn at Apogee

I am relatively new to rocket physics and am looking into modelling burns. Is there a good place to start modelling an orbital burn? I know about the rocket equation but perhaps that is not what is ...
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1answer
82 views

My vector math seems to be off in this 2D simulation of a solar system

I intend to simulate gravitational acceleration on a 2D plane (simplified, no gravitational constant). My code is interpreted without any error in the console, but instead of having the two circles ...
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Why does Gravity Simulator's rendering of TESS' orbit look like a pretzel? How can I unpretzefy it?

Below is a screen shot from the amazing Gravity Simulator driven by our own @HappyKoala. If you haven't seen it recently go check it out now, then come back in 30 minutes and read the rest of my ...
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Cis-L2 Libration Point Halo Orbit

Queqiao became the first satellite to orbit the Cis-L2 libration point (far side of the moon). Link: https://en.wikipedia.org/wiki/Chang%27e_4 Does anyone have any insight on how to model this orbit ...
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Is this plot of deep space trajectories correct? Did most launch retrograde from Earth? Why do some change direction between planets?

This answer contains some nice plots of deep space spacecraft trajectories. Noticing that Voyage 2's heliocentric velocity dropped substantially just before 1990 I wanted to see why. Wikipedia's ...
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Why not simulate certain regions of the atmosphere of Venus?

Many people would like to know if any form of life could survive anywhere in the atmosphere of Venus. Researchers have simulated conditions on Mars and found that after a month some cyanobacteria ...
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1answer
369 views

Simulating launch velocity of falcon 9

Help! I finished my numerical simulation of falcon 9 launch in google sheets, where I calculate all the value changes with time. But, when I looked at real launch to compare the values, I got really ...
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1answer
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Is this C# code to obtain the coordinates of the planets correct?

This should be a comment to an 2012rcampion's answer to this question: Determining orbital position at a future point in time I'm using the linked data of that answer, under "Computing Position ...
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1answer
179 views

Why we do not refuel and assemble in orbit?

Using simple math or playing Kerbal SP inevitably leads to re-using first stages and refueling in orbit for missions far away. It seems, it is always the most economical and simple approach to refuel ...
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3answers
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Is there a mathematical formula to calculate drag force without empirical testing?

Typically people put the interested rocket prototype in a wind tunnel to find out the drag force and use the drag force equation to calculate the drag coefficient of the rocket model. I am wondering ...
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7answers
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The Martian: Does it really take a supercomputer to calculate spaceflight maneuvers?

My preemptive apologies for asking a question about a movie, and the spoilers within said question, but considering the widespread support for its scientific plausibility, I'm hoping you'll let it ...
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2answers
193 views

How much of the Shuttle was physically realized in the simulator?

How much of the Shuttle physically existed in the simulator? Was it just the flight deck? Or were the mid-deck, lower equipment bay, and/or payload bay also included?
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1answer
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Was it possible to simulate another atmosphere during Shuttle training?

This answer points out that the Space Shuttle's cabin atmosphere was designed to be equivalent to sea level air, in terms of both total pressure and oxygen partial pressure. However, could any of the ...
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1answer
97 views

What happened during this shuttle simulation malfunction involving a failure of a shuttle arm joint while moving the JEF?

This author (cough) begins to relate the details of a particular training incident during simulations for STS-127. However, they very sadly have not finished the tale. Does anybody (cough cough) know ...
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1answer
256 views

How does one test Ground Segment communications with, and “downlink” data from a spacecraft that's still on the ground?

NASA News item Ground Segment Testing a Success for NASA’s James Webb Space Telescope says: Testing teams have successfully completed a critical milestone focused on demonstrating that NASA’s James ...
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232 views

Accuracy of converting from TLE/Orbital Elements to Cartesian if used for other propagator?

Say that I wanted to propagate a real-life satellite based on an initial position in space. However, the only source of data I can get is from a tracking website like CelesTrak or Space-Track, where ...
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2answers
711 views

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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Does Kerbal Space Program have a software migration path to Lagrange points, halo orbits, and other 3-body goodies?

At about 05:37 in Scott Manley video Kerbal Space Program 2 - What We Know About The Sequel So I’m cautiously optimistic and I really obviously want this to be ...
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0answers
60 views

Rocket Engine - Actuator in Loop Simulations

For Actuator-In-Loop simulations, why are the rocket engine nozzles along with the thrust vector control assembly (including the actuators) kept inverted on a platform like in the attached image or as ...
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1answer
141 views

Are planet orbits available to download in some vectorial format file?

I would like to work with solar system planet orbits in a Geographic Information Software like QGIS, so: Are available to download the orbits of solar system planets in some vector format? EDIT: ...
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Has NASA ever included a ground controller or astronaut becoming insane/irrational/belligerent in a training simulation?

NASA training simulations have included a wide variety of problems thrown at the pilots and ground controllers -- not only the typical technical failures, but also some unusual outside-world stuff ...
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2answers
862 views

Getting state vectors from JPL Horizons ephemerides

I'm simulating the Sun-Earth-Moon system by numerical integration of equation of motion. I've confused a little bit in JPL Horizons ephemerides. Could anyone explain (if possible, on pictures), how ...
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1answer
87 views

Direct conversion of Keplerian orbital elements to Equatorial coordinate system

In the context of a computer simulation of satellites that orbit earth, I am looking for a (accurate) method for converting Keplerian orbital elements directly to Equatorial coordinate system. The ...
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1answer
144 views

Optimal point in LEO to perform interplanetary injection burn

I wrote a simulation program in Python to calculate Earth <-> Mars trajectories. Now I would like to test it agains well known trajectories. I used NASA Ames Research Center Trajectory Browser ...
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1answer
141 views

Simulate Radar Trajectory Data

I have a need to train a model on various trajectory data of flying objects (for clustering purpose). I found trajectory data of air planes online. But since trajectory data for missiles, satellites ...
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1answer
112 views

Implementation of NASA Breakup model Area to Mass distribution

In the research "NASA's new breakup model of evolve 4.0" the implementation for the area to mass distribution of fragments produced by collisions and explosions is provided. The distribution ...
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2answers
120 views

Possible idea for a simulation in orbital mechanics using data from the JPL [closed]

I have to write a research essay and have decided to write it on orbital mechanics where I would use data from the JPL to perform an experiment (simulation). I was thinking of using the location data ...
3
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1answer
103 views

ECSS Simulation Modelling Portability

Is there anyone who applied "ECSS-E-ST-40-07C Space engineering – Simulation modelling platform standard" to their simulation? I wonder is the standard really applicable or applied by someone. Some ...
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1answer
1k views

What's is this very CGI looking clip in this NASA video of the Alpha Magnetic Spectrometer installation?

This is the NASA video AMS Time Lapse Installation a time-lapse of the Alpha Magnetic Spectrometer (AMS) installation at the International Space Station. At about ...
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1answer
91 views

How significant is orbit propagator choice/error when considering a year-long satellite coverage simulation, and which is the most appropriate?

I'm currently considering a project to simulate the (Earth-seeing) coverage of 1 or more satellites over the course of a year. The point would be to compare how different orbits result in different ...
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2answers
537 views

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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1answer
204 views

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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9k views

Can Kerbal Space Program act as a suitable simulator with the right mods?

The game is great alone, but if we install a mod called Real Solar System and another called Realism Overhaul, the force of gravity, engine power atmospheric heights and everything happens to real ...
2
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1answer
124 views

Controlling suicide burn landing location in a python simulation?

I recently asked a question in stackoverflow about Simulation of suicide burn in openai-gym's LunarLander. Sadly most of my assumptions about suicide burn implementaion were wrong but the answer given ...
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1answer
454 views

Why is FORTRAN recommended for astrodynamics rather than MATLAB?

I understand that FORTRAN might be faster in terms of computation time, but I don't understand why it is always recommended by people in the field. Everyone tends to avoid MATLAB for astrodynamics; is ...
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2answers
248 views

Was a real Space Shuttle ever used as a really big simulator?

@OrganicMarble's answer to How much of the Shuttle was physically realized in the simulator? makes me wonder if Shuttle crew ever sat or stood or otherwise experienced being in an actual Space Shuttle ...
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0answers
204 views

Is “Space Shuttle” written as a proper noun in the spaceflight industry?

Writing the question Was a real Space Shuttle ever used as a really big simulator? (and several others) I capitalize Space Shuttle because as far as I know, that's the actual name of NASA's spacecraft,...
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4answers
14k views

Why is my Earth simulation slower than the reality?

It took me a long time to create a simulation of the Earth like that. I wanted to show the real spinning speed of the Earth. Here's my video: From this NASA live ...
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1answer
650 views

How were Apollo spacesuits cooled during simulations/rehearsals on Earth?

The answer and comments to How have space suits dissipated the heat removed from astronauts? explain that the Apollo space suits used the sublimation of ice into the vacuum of space to constantly ...
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0answers
132 views

Recalculate Orbital Elements after a ΔV

I would like to write a program able to simulate a keplerian orbite given an initial position and velocity (r0, v0) and able to manage accelerations in different directions. To simulate the orbit, I ...
7
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1answer
241 views

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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2answers
780 views

Does anyone know how the Flight Club website simulates Falcon 9 launches?

Does anyone know how the Flight Club website is able to provide falcon 9 launch simulations? Given the estimated weight, fuel mass, thrust, ect, how are they able to provide a graph of how it could ...
3
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1answer
474 views

Rocket Launch Simulation Source Code Locations

As you can take from the title, does anyone know where I could find the source code for a working launch simulation type application such as FlightClub for example?