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a humble lich

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Everything posted by a humble lich

  1. I believe there is a lot of confusion about what the OP was asking. I don't think he is asking what is the most difficult mission in the game. Instead, he said you can only put one honour on your ribbon for each planetary body, which one of those honours is harder? For example, for my Mun ribbon should I put that I built a rover which drove a significant percentage of Mun's circumference, or that I buit a Mun base? It seems that question is different for each body but clearly there are some similarities--clearly landing a rover and driving it around any body is more difficult than just landing there.
  2. The "six words you never hear at NASA" comic was how I discovered KSP actually.
  3. An asteroid isn't needed for a skyhook, you can use it for some space elevator designs. And from a practical perspective, this is completely pointless. In theory, a real skyhook could regain orbital energy by running current through the tether and work against the Earth's magnetic field. Since you can't do this in KSP (does Kerbal even have a magnetic field?) the station will loose a little energy every time it launches something. And you are getting very little extra boost. Being able to go from a 80 km orbit to a 82 km orbit isn't really that big of a help. Making the thing longer would be better, but the longest you can launch in one shot is about 200 m (I think, I forget the exact height), so a 2 km tether already involves 10 launches. And at some point I suspect KSP will have problems with structures that are too long. I decided I will return to the project after my docking skills are better. The whole thing was just a exercise to prove it was possible. I don't understand why more people don't do this. Jet engines are awesome for the first stage of rockets. Although admittedly they are a little silly, are they really more silly than the Kerbalesque asparagus staged rockets that are made?
  4. I think the biggest I put into orbit was my attempt at a skyhook. Basically, a smaller brother to the space elevator, it is a long rotating tether to boost craft into a higher orbit without using fuel. While it is currently on hold until I get better at docking, I did launch the first bit. At only 176 tons it was not too heavy, rather the launch was problematic because it was so tall and wobbly. Initial launches would shake enough to fling mainsails at full thrust backwards.
  5. I would like to be involved with this too. I don't have any experience writing mods for KSP and my C is rusty, but I do have a lot of experience doing dynamical simulations.
  6. Actually, the more I think about it, for the Kerbal-Mun system at least, Lagrange Points are possibly more stable in the current model than with Newtonian dynamics. I suspect that interactions from Minmus will fairly rapidly pull a craft away from L4/5. I wanted to try the stability calculation today, but have been to lazy. :-)
  7. First, good article, I was wondering many of this myself. I had a couple thoughts on reading it, from my experience in doing numerical integration. 1. With regards to integration schemes, given how smooth planetary orbits are, you could probably use a much higher order integration scheme. The RK45 that you used is good, I remember using a 7th/8th order Runga-Kutta method that I liked too. Or if you wanted to be super serious, you could use ODEPACK, a standard numerical library for solving ODEs. I remember being impressed on the speed gain I would get using ODEPACK compared with a simpler Runga-Kutta. Whether it is worth the programing time is another question. 2. As for not being able to find stable Lagrangian Points, I would want to see more simulation results, but I would guess that the numerical errors from your integration scheme are causing them to loose stability. Runga-Kutta methods do not conserve energy, so for physical systems where that is important (like planetary dynamics), they will introduce errors in the long term. These effects are often worst around stable points. There exist integration schemes that do preserve energy, but these are generally much more complex. Other possibilities are that perturbations from Minimus are causing you problems, or possibly that you have a bug somewhere (which I'm sure isn't the case, after all, my programs _never_ have bugs, why would anybody else's? :-)) p.s. This is the first time I've posted here!
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