# Tag Info

13

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 Dynamics software instead of in wind tunnel testing. can we simply look at the system of one air molecule and the rocket, calculate the instantaneous change in ...

10

This is done in a anechoic chamber. Such chambers are padded on the inside with material that absorbs electromagnetic waves. On the outside, the rooms are shielded like a Faraday cage, so that no external radiation enters the room. They put the whole satellite in the room and by putting a transmitter and receiver in the room in the right locations and using ...

8

It is possible to compute rather than measure the drag on an object. However the answer to the specific technique you suggest: can we simply look at the system of one air molecule and the rocket, calculate the instantaneous change in momentum of the air molecule after collision as the resistive force, and then sum up the forces experienced by all air ...

7

Several things that KSP does not model: The challenges of actually docking two things mechanically together without a handy human such that the plumbing works (leaks have a tendency to go bang) The extra instrumentation required to dock with enough reliability to not risk the mission (need duplicate equipment). Notably for the ISS many craft just take ...

6

There is a mathematical formula, but it requires knowing the pressure and velocity distribution around the surface of the object: $$D=\int_{S_{upper}}\left[-pcos(\theta)+\tau_wsin(\theta)\right]dA +\int_{S_{lower}}\left[psin(\theta)+\tau_wcos(\theta)\right]dA$$ where $S_{lower}$ and $S_{upper}$ refer to the lower and upper surfaces, respectively, and $\theta$...

3

One of the Space Shuttle simulators flew The Shuttle Training Aircraft was a Grumman Gulfstream II that was heavily modified so that pilots could train to land the shuttle in an aircraft that had similar flight characteristics to the real shuttle (when landing). It extended the gear and ran the engines with the thrust reversers engaged so that it could ...

3

To answer the revised question, "does KSP have a software migration path that will allow for n-body physics options" Yes, it has its "mod" framework, which has been used to provide these features for several years.

2

You don't have to implement the propagator. You can download it from space-track.org, just like you download TLEs. Go to space-track, click "Help", then click "SGP4", and arrive at https://www.space-track.org/documentation#/sgp4 . From there, pick Windows or Linux, and download compiled shared libraries of the latest SGP4 as released ...

2

I don't see the exact equation that is in the question, but it looks like it's derived from equations in Chapter VI Paragraph C "Drag of Streamlined Shapes" in Hoerner 1965 Fluid-Dynamic Drag. At least, there is a marked similarity. I found similar equations (at least the same power law) in a book I own, McCormick 1979 Aerodynamics, Aeronautics, ...

1

Edited in response to very constructive criticism from @DavidHammen and @CallMeTom. I agree with them, but I didn't say those things in my initial answer, and I should have. If the only source of data you have is a TLE, then you are starting from a low-quality initial state, which you should expect to be wrong by several kilometers. All a high-quality ...

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