72 votes
Accepted

Why is my Earth simulation slower than the reality?

In your simulation, the camera (or the viewers perspective) is stationary in what seems like in an altitude of a geostationary orbit. However the ISS is not stationary, it is travelling 7.6 km/s. It ...
Star Man's user avatar
  • 5,928
58 votes

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

I helped (somewhat) to develop the RSS/RO/RP-1 mod suite (which, respectively, are and do: Real Solar System, which gives you the Sol system, appropriately sized and massed; Realism Overhaul, which ...
Anton Hengst's user avatar
  • 10.7k
53 votes
Accepted

Game for teaching basics of orbital mechanics

I want to allow students to tinker around with basic central force motion and see the ways in which conic sections are altered by thrust, etc. Seeing/enacting an example of rendezvous (maybe in a CW ...
Russell Borogove's user avatar
48 votes
Accepted

Is there a mockup of the ISS on the ground?

There are multiple mock-ups of the ISS, for various purposes: The Space Vehicle Mockup Facility at Johnston space center contains replicas of many modules of the ISS, some of them assembled together. ...
SE - stop firing the good guys's user avatar
40 votes
Accepted

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

For all simulators, the core question is: What is it trying to simulate? Real world space travel has many different motivations, like for instance: Science Military interests Money Prestige ...
SE - stop firing the good guys's user avatar
31 votes

The Martian: Does it really take a supercomputer to calculate spaceflight maneuvers?

Well, developing low-thrust trajectories does take more computation than impulsive trajectories (e.g. like Voyager, which was done with rather primitive computers). You have no choice but to run many ...
Mark Adler's user avatar
  • 58.2k
29 votes
Accepted

Is this plot of deep space trajectories correct? Did most launch retrograde from Earth? Why do some change direction between planets?

The diagram you show is the digital version of a drawing by someone with an Etch-a-Sketch: completely inaccurate. The diagram below is accurate, showing Pioneer 10 & 11 and Voyager 1 & 2 ...
Tom Spilker's user avatar
  • 18.3k
24 votes
Accepted

Who does these mesmerizing simulations of the phases of the Moon? And how?

I made the images on Wikipedia with my own software. The original on Wikipedia is here. The main work needed is getting the proper position of the Moon with its precessing elliptical orbit, while the ...
Tom R's user avatar
  • 556
24 votes

Game for teaching basics of orbital mechanics

Personally, I teach orbital mechanics classes to preschoolers, elementary and middle school kids using a makeshift trampoline with stretchable cloth clamped to the rim. Place a heavy weight (e.g. a ...
Paul's user avatar
  • 1,984
23 votes
Accepted

If Earth had a second moon, where would it be positioned?

Certainly the Earth could have ended up with additional moons, and Newtonian physics can say some things about the kinds of orbits they might have, but there is a range of possibilities. First of all, ...
Mark Foskey's user avatar
22 votes

Why is my Earth simulation slower than the reality?

As others have noted, the ISS orbits the earth extraordinarily quickly, and that explains the discrepancy. However, there may still be a small error in your simulation. Whether or not there is an ...
Eric Lippert's user avatar
21 votes
Accepted

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

That's generated by one of the Johnson Space Center robotics/EVA planning tools, called MAGIK (Manipulator Analysis-Graphic, Interactive, Kinematic). Here is a screenshot of a MAGIK video used when we ...
Organic Marble's user avatar
20 votes

The Martian: Does it really take a supercomputer to calculate spaceflight maneuvers?

Calculating an energy-optimal orbit for a simple thing like Earth->Mars is no big deal. Even using low-thrust engines doesn't add much to it. It would be tedious but you could do it on a calculator. ...
Loren Pechtel's user avatar
16 votes
Accepted

Developing intuition about altitude and velocity in multi stage rockets

I will argue that your simulation outcome is not reasonable. Consider what happens if we decouple your multi stage rocket right at launch, making no use of the first stage at all. That is, just using ...
SE - stop firing the good guys's user avatar
15 votes
Accepted

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

Flight Club creator here. Thanks for the ping @uhoh ;) @RussellBorogove got the implementation of the code spot on and it's actually almost exactly what I do. The only points that I feel are worth ...
Declan Murphy's user avatar
14 votes

Is there a mathematical formula to calculate drag force without empirical testing?

I am wondering whether there is a mathematical formula that we can use to calculate the drag force without empirical measurements. Yes, much modern rocket design is done with Computational Fluid ...
Russell Borogove's user avatar
14 votes
Accepted

Have any bits of a space mission ever collided with a planet or large moon (not Earth) that was not a target of the mission?

Yes https://scitechdaily.com/space-junk-just-crashed-into-the-far-side-of-the-moon-at-5800-mph/ A piece of space junk (China or spaceX) hit the far side of the moon
Catprog's user avatar
  • 434
13 votes

Why is my Earth simulation slower than the reality?

The ISS takes approximately 90 minutes to circle the Earth. This presumably results in the higher apparent speed of rotation.
Organic Marble's user avatar
12 votes

Getting state vectors from JPL Horizons ephemerides

Keywords: Horizons tutorial I'll work one example all the way through, and include the exact output you should get so you can check your results. Then you can change one item at a time to get the rest ...
uhoh's user avatar
  • 149k
12 votes

Game for teaching basics of orbital mechanics

UC Boulder has a project, PhET, that has many free, interactive, in-browser math and science modules. They have one called Gravity and Orbits that's written in HTML5, making it compatible with most ...
Manuel J. Diaz's user avatar
12 votes

Game for teaching basics of orbital mechanics

Spaceflight Simulator An Android software, but it's possible to run it on a PC as well. It's 2d, so it's much simpler to use than 3d software. There are some premium features ($4 unlocks all of them ...
vsz's user avatar
  • 318
12 votes
Accepted

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

Note: there were a lot of training simulators. This answer concentrates on the Shuttle Mission Simulators. There were mockup type simulators like the Crew Compartment Trainer (CCT) that replicated ...
Organic Marble's user avatar
11 votes

Game for teaching basics of orbital mechanics

Probably too basic for what you want but Osmos (https://osmos-game.com/) has modes where the player is basically orbitting an attractor and has to change orbit to rendezvous with other objects in ...
Eric Nolan's user avatar
11 votes

Object slowest at periapsis - despite correct position calculation

If I understand correctly, your $p, q$ are essentially cartesian coordinates, and you're trying to get the velocity components in those two orthogonal directions. However, you're taking the derivative ...
uhoh's user avatar
  • 149k
10 votes
Accepted

How might one approach using AI (convolutional neural network) to predict collisions in orbit?

As a data scientist with an interest in space stuff, I am well positioned to give an answer this question. I must confess I don't understand fully what is going on in this system from just the lecture ...
Ingolifs's user avatar
  • 6,458
10 votes
Accepted

Why is FORTRAN recommended for astrodynamics rather than MATLAB?

As many of the comments have already mentioned, there are several different reasons people might recommend the use of Fortran over Matlab. One of the most straightforward answers is that a lot of ...
Chris's user avatar
  • 663
9 votes
Accepted

What does "masquerading zero gravity" mean?

'masquerading' is a bit of a misnomer. Lying in bed simulates some of the effects that zero gravity has on the body. This article has a decent introduction: NASA needs more volunteers for its bed-...
Hobbes's user avatar
  • 128k
9 votes

Would current computer technology have made the Moon landings any easier?

In general, the astronauts could operate the spacecraft autonomously without help from mission control. Specifically, you could land on the far side of the moon. The Apollo spacecraft each had a ...
DrSheldon's user avatar
  • 48k
9 votes
Accepted

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

Nearly all Earth training was performed in the A6L model spacesuit (seen in the pictures above). Actual missions flew with the A7L model suit. Differences include: The outer (EVA) layer of the A6L ...
DrSheldon's user avatar
  • 48k
9 votes

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

There was a Terminal Countdown Demonstration Test (TCDT) performed late in the training flow for each mission in which the crew would fly out to Florida where their Orbiter was stacked on the pad. ...
Organic Marble's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible