Jump to content

cantab

Members
  • Posts

    6,521
  • Joined

  • Last visited

Everything posted by cantab

  1. I believe the flaw in this argument is that you are implicitly putting requirements on the transfer other than "most efficient". An orbit just under escape speed is necessarily highly elliptical with an apoapsis arbitrarily distant from the primary, and at an arbitrary distance from the primary it takes a negligible amount of delta-V to change from any closed orbit to any other closed orbit.If we limit ourselves to transferring between closed stable orbits then intuitively I would expect the most demanding orbital change to then be a 180-degree plane change of the lowest stable orbit. I believe (but have not proven) the most efficient transfer would be a bi-elliptic. That would be a burn to nearly escape speed, an arbitrarily small burn at apoapsis arbitrarily far from the primary, and a circularisation from nearly escape speed. At any given height escape velocity is √2 times circular orbit speed. Therefore the maximum required delta-V for a transfer between two orbits is 2x(√2-1) or 82.8% of the speed of the lowest stable orbit. Far less than twice the escape speed, which is 2x√2 2.83 times the speed of the lowest stable orbit. Of course you can use more - this analysis assumes that one you are given your orbits you want to get between them as efficiently as possible. There is also the big caveat that I am assuming an unlimited sphere of influence. If we do not limit ourselves to closed orbits then of course we can choose two trajectories shooting through the system as fast as we like and have any delta-V requirement to transfer we like. If we do not limit ourselves to stable orbits, and instead allow suborbital trajectories, I am unsure what impact this would have. PS: By considering the bi-elliptic transfer, rather than the Hohmann transfer, I think you can prove that a 180 degree plane change of the lowest stable orbit is indeed the most demanding orbital change. If either the initial or final orbit is any higher it will have a lower orbital speed and correspondingly a lower escape speed at that altitude, and thus require less delta-V to escape from or enter from escape.
  2. It's not as dramatic as it sounds, you just need to at some point be on a collision course with the Sun, no matter how far away you are. It does require either a boatload of delta-V or a Jool gravity assist though.
  3. Most players don't bother working out the delta-V for manoeuvres themselves. For orbital changes the game's manoeuvre node system gives that to us. For landings, takeoffs, and travel to other planets or moons we use "delta-V maps", there are lots available.
  4. All craft in KSP are built like trees - when you place a part you attach it to one, and only one, existing part. That's why you can't use the tricoupler to join three stacks back together. So if you have an upper stage that needs more than one engine you need one part centrally that you can build the lower stages down from - maybe an engine, maybe some other part. Then the other engines need to be attached however you like.
  5. Probably. You need to equip the tool by right-clicking it in the inventory, then hold down x to use it and click on the relevant part.
  6. Does the ore have to mined from anywhere? If not then just tweak it in a container in the VAB before launch. If you already launched you can rush the ore to the ship before it makes Jool, same as if you realised it needed extra life support.
  7. Similar issue here, again with Pergas. I touched down, the craft stopped, but was still counted as "Flying Low". I was able to work around the problem by quicksaving, and editing the quicksave to set the affected craft as landed. 000_Toolbar K+PlanetShyne.cfg PFSystems Asclepius K+Resources.cfg PlanetShine DistantObject ModularFlightIntegrator PreciseNode DMagicOrbitalScience ModuleManager.2.6.6.dll SCANsat FerramAerospaceResearch ModuleManager.ConfigCache ScienceAlert K+DistantObjectEnhancement.cfg ModuleManager.ConfigSHA Sigma KerbalEngineer ModuleManager.Physics Squad KerbolPlus ModuleManager.TechTree toolbar-settings.dat KittopiaSpace New_Horizons Trans-Keptunian Kopernicus OPM TriggerTech Kopernicus is the version supplied with Kerbol Plus.
  8. Actual Science Wrote down the figures from the barometer by hand during the descent, and they graphed up pretty nicely. Looks like about a 9 km scale height, which is information the game doesn't give me.
  9. I'd just like to say that this mod is what science parts in KSP *should* be. Representations of real space experiments, complexity in considering how to use them, and not all being super tiny. I love the laser experiment, when I activated it and the laser and camera sprung into action I was surprised and delighted.
  10. Favourite stock part: All hail the king of engines. Favourite mod part: From DMagic Orbital Science. Because LASERS.
  11. Atmospheric planes are mainly useful for survey contracts, which can yield some nice science and money. Some players use rockets for those, but I feel planes are better at hitting the target, especially if there's a landed site since a plane can simply taxi to it. A tip: once you complete a contract you can leave your plane landed out, it could be in a good place to take another contract and save you some flying time. Spaceplanes are mainly useful for cheaply launching crew and small payloads. And don't forget there are six bodies with atmosphere. Laythe in particular is an obvious target if you have trouble precision-landing a capsule.
  12. Did you download and correctly install both the main Kethane download and the 1.0.x compatibility patch?
  13. https://www.reddit.com/r/KerbalAcademy/comments/1qu5jv/deltav_charts/ These are the most comprehensive set of delta-V charts I have found, and allow you to answer questions like that, as the Reddit post explains. Though do note it does not have updated values for ascents from atmo bodies. For going from low Ike orbit to Jool we get Direct transfer: 1270 m/s Low-over-Duna: 1130 m/s Not much in it. Unless I was looking to absolutely minimise mass I'd take whichever option is more convenient.
  14. I just see no reason it can't have a bottom stack node.
  15. I think I prefer New Horizons myself, but this is good too, especially for anyone who has RAM issues with NH. I may incorporate the Duna into my system though, it looks really great in the pics.
  16. Looking good. I think I'll wait and let others find the bugs before I add it to my install, but more planets is always welcome by me.
  17. Possible considerations: The Outer Space Treaty refers to "celestial bodies" without defining what that means. A company could argue that a rock small enough to tow around does not qualify as such. While the Outer Space Treaty applies to nations, Article VI states that nations are responsible for actions carried out by non-governmental entities. I would take that as meaning for example that if the United Kingdom permitted a British company to test a weapon in space then the UK would be considered to have breached the Outer Space Treaty. Article VIII states that This will I think be key. The likely argument is that a chunk of ore mined from an asteroid counts as an "object constructed on a celestial body", and will thus be owned in accordance with the laws of the country with jurisdiction. The closest precedent for this are the missions that have returned rock samples from the Moon. In 1993 samples from the Soviet Luna 16 were sold at auction with no legal objections from anybody. Though on a tiny scale, that strengthens the case that mining other worlds for profit is lawful. Article XVI permits states to withdraw from the treaty in any case.
  18. Ask me again when I've actually got round to playing Minecraft
  19. Don't sail anywhere near a rocket launchpad when there's a launch or everyone on this forum will hate you
  20. For what it's worth you could just do like the stock game largely does and choose a value based on gameplay. Planes in my view shouldn't be using reaction wheels, so you just need enough power to run a probe core, and maybe whatever a life support mod wants.
  21. Despite not having a K suffix the Pentium G3258 is indeed one of the handful of "unlocked" modern Intel processors.
  22. Here's a quick test. Wikipedia does not have ads - never has and never will. If you see ads on Wikipedia then you have a nasty program on your computer producing those ads, and doing kraken knows what else as well. https://en.wikipedia.org/wiki/Main_Page Then Spybot Search & Destroy is good at removing such programs. https://www.safer-networking.org/
  23. Over a hundred years, not sure which sort of years. That is what happens when you go to Eeloo and back using lots of gravity assists.
×
×
  • Create New...