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The issue with ksp is that you first need to figure out the rocket design before you start on orbital mechanics (that's why I ended up building my own web simul

by Aachen 2y ago

The issue with ksp is that you first need to figure out the rocket design before you start on orbital mechanics (that's why I ended up building my own web simulator for that part anyway, and also because ksp doesn't support my OS)

nkrisc 2y ago
The design requirements are pretty forgiving and as I recall there are some pre-built rockets you can use.
lagrange77 2y ago
> I ended up building my own web simulator for that part anyway Is it public?
- Aachen 2y ago
  Sure, didn't want it to seem like an ad, also because it's not quite ready for prime time, I still intend to make a better UI... https://lgms.nl/p/badgravity/ https://lgms.nl/p/badgravity/ For something ksp-like, I guess the easiest is to press "play" on the Pluto scenario on the left. Note the hints in the top left. Trying it myself now, it seems the scenario is set quite quickly, so I'd set the simulation "steps per run" to maybe 5, and the thrust should be something on the order of 1 (I thought the scenario data should have set that appropriate to the craft but apparently not) Edit: oh yeah and it expects arrow keys and a scroll wheel, there is no button overlay implemented for mobile yet
  - lagrange77 2y ago
    Thank you, it's really cool! I started something similar, but way less sophisticated. Basically i implemented a n-Body solver in Julia, compiled it to Webassembly and did the drawing with canvas, like you. This motivated me to work on it again. > The issue with ksp is that you first need to figure out the rocket design before you start on orbital mechanics Come on, it's not rocket science.
    - nico 2y ago
      > a n-Body solver in Julia, compiled it to Webassembly and did the drawing with canvas Awesome, do you have GitHub repo with the code? or a website with it running? would love to see it
      - lagrange77 2y ago
        Unfortunately not, i couldn't solve some (numerical) stability issues and i buried it in my "dev directory". But if i'll get it presentable, i'll be doing a Show HN.
        nico 2y ago
        Thank you. It would be great if you posted it! I’ve been simulating some halo orbits and also running into stability issues It seems it’s pretty typical and depends on the integration method used, as well as the timestep In general it is quite a hard problem to solve. Mathematically, it’s a very difficult problem. But also computationally, it is almost impossible to fully simulate an n-body system without getting chaotic orbits. Then you have to either cheat (by manually tweaking trajectories) or just picking a pretty small time range for the simulation
        lagrange77 2y ago
        Exactly. What i also learned was, that i had to take a (primitive) collision detection into account. Otherwise bodies can come so close to each other, that the gravitational forces can go very high or even to (machine) infinity.
deleted 2y ago
[deleted]
mmh0000 2y ago
Getting to orbit (or anywhere really) is very well documented in the KSP world. There are tutorials, videos, and guides galore. This tutorial[1] includes details on how to build your rocket, how to fly your rocket and how to do successful reentry. [1] https://wiki.kerbalspaceprogram.com/wiki/Tutorial:_How_to_Get_into_Orbit https://wiki.kerbalspaceprogram.com/wiki/Tutorial:_How_to_Ge...

by Aachen 2y ago

nkrisc 2y ago

The design requirements are pretty forgiving and as I recall there are some pre-built rockets you can use.

lagrange77 2y ago

> I ended up building my own web simulator for that part anyway Is it public?

Aachen 2y ago
Sure, didn't want it to seem like an ad, also because it's not quite ready for prime time, I still intend to make a better UI... https://lgms.nl/p/badgravity/ https://lgms.nl/p/badgravity/ For something ksp-like, I guess the easiest is to press "play" on the Pluto scenario on the left. Note the hints in the top left. Trying it myself now, it seems the scenario is set quite quickly, so I'd set the simulation "steps per run" to maybe 5, and the thrust should be something on the order of 1 (I thought the scenario data should have set that appropriate to the craft but apparently not) Edit: oh yeah and it expects arrow keys and a scroll wheel, there is no button overlay implemented for mobile yet
- lagrange77 2y ago
  Thank you, it's really cool! I started something similar, but way less sophisticated. Basically i implemented a n-Body solver in Julia, compiled it to Webassembly and did the drawing with canvas, like you. This motivated me to work on it again. > The issue with ksp is that you first need to figure out the rocket design before you start on orbital mechanics Come on, it's not rocket science.
  - nico 2y ago
    > a n-Body solver in Julia, compiled it to Webassembly and did the drawing with canvas Awesome, do you have GitHub repo with the code? or a website with it running? would love to see it
    - lagrange77 2y ago
      Unfortunately not, i couldn't solve some (numerical) stability issues and i buried it in my "dev directory". But if i'll get it presentable, i'll be doing a Show HN.
      - nico 2y ago
        Thank you. It would be great if you posted it! I’ve been simulating some halo orbits and also running into stability issues It seems it’s pretty typical and depends on the integration method used, as well as the timestep In general it is quite a hard problem to solve. Mathematically, it’s a very difficult problem. But also computationally, it is almost impossible to fully simulate an n-body system without getting chaotic orbits. Then you have to either cheat (by manually tweaking trajectories) or just picking a pretty small time range for the simulation
        lagrange77 2y ago
        Exactly. What i also learned was, that i had to take a (primitive) collision detection into account. Otherwise bodies can come so close to each other, that the gravitational forces can go very high or even to (machine) infinity.

deleted 2y ago

[deleted]

mmh0000 2y ago

Getting to orbit (or anywhere really) is very well documented in the KSP world. There are tutorials, videos, and guides galore. This tutorial[1] includes details on how to build your rocket, how to fly your rocket and how to do successful reentry. [1] https://wiki.kerbalspaceprogram.com/wiki/Tutorial:_How_to_Get_into_Orbit https://wiki.kerbalspaceprogram.com/wiki/Tutorial:_How_to_Ge...