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tomf

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Everything posted by tomf

  1. Without running the numbers I think that your best bet is to leave Minimus orbit and wait in a circular orbit around Kerbin with a radius = Minimus for your launch window. Dropping your PE to low Kerbin orbit might give a small saving but certainly not enough to be worth the hassle and I think it will probably end up slightly more. If you were starting from scratch building at Minimus from components ferried from Kerbin would be very inefficient, the cost of getting them to Minimus is considerably more than the saving from starting from a higher orbit.
  2. The return trip always (if you pick the optimum transfer point) takes the same delta-v as the outgoing trip. The differences you see (e.g. returning from mun or gilly) is due to aerobraking in the parent bodies atmosphere. For a full mission to Duna (numbers taken from the current chart on the kerbin wiki page http://wiki.kerbalspaceprogram.com/w/images/7/73/KerbinDeltaVMap.png) Takeoff ~4550 Kerbin escape 950 Duna intercept 110 Duna capture 370 Duna landing 1380 Duna Takeoff ~1700 Duna escape 370 Kerbin intercept 110 Kerbin capture 950 Kerbin landing ? very small As you can see the chart is symetrical. However the numbers in red are orbit changes for which you can use aerobraking, you should be able to save about 90% of the given delta v, which does mean that it ends up being masively cheaper to get back from Duna than it was to get there. Also not that the chart has split out the number to escape Kerbin and to intercept Duna. However the numbers have in fact been calculated on the basis that you will do a single burn from a circular orbit of the departure body.
  3. I had the same thing recently when I landed on a slope on Gilly. I used my RCS to bring the lander to a temporary halt and did an EVA. I stopped moving long enough for my Kerbal to fly around with every step and try jumping 900m. I expect it will stop anyway when it gets to the bottom of the hill
  4. If you want to have a higher time warp then you need to switch to another craft I have a craft that is just a probe that sits on the runway at high warp while I wait for the alarm I have set in the alarm clock to send a different ship off interplanetary.
  5. I did an example of the maths here http://forum.kerbalspaceprogram.com/showthread.php/27171-Calculating-interplanetary-delta-v
  6. If you wanted to fake a munar synchronous orbit you would need to be at an altitude of 2.9e6 meters away from the surface of the mun, 500 km outside its sphere of influence. That would give you about 50 days before you drifted into the soi.
  7. The alexmoon site has a few options, some which have a mid course inclination burn, some which do the inclination change during the initial burn.
  8. A quoted delta-v is for a specific mission plan. The values read from maps are for the most efficient simple plan, launching when the planets make the optimum angle to each other and using a hohmann transfer. They are based solely on the orbits and masses of the starting and ending bodies (and the mass of the sun). The maps ignore eccentricity and inclination. The maths for this isn't to hard, I wrote a post a while ago http://forum.kerbalspaceprogram.com/showthread.php/27171-Calculating-interplanetary-delta-v. There is a calculator that will give you delta-v requirements for arbitrary departure dates taking inclination and eccentricity properly int account http://alexmoon.github.io/ksp/ but the maths of that are slightly beyond me. Working out the delta-v requirement for a mission that is going to use gravitational slingshots is going to be harder still.
  9. Mission Get your rocket into a roughly 100km circular orbit use either protractor, kerbal alarm clock, mechjeb, http://alexmoon.github.io/ksp/, http://ksp.olex.biz/ to work out the correct time to head off for eve. Select Eve as the target you will want to do a burn in kerbin orbit of about 1000m/s. Your resulting orbit should leave kerbin's SOI traveling parallel to Kerbin's orbit and backwards. Drag the maneuver node around until it is in the right direction. Fiddle with the node until it just brushes Eve's orbit. You should see that Eve will be very close to the point where you touch at the same time as you get there. Do the burn to leave Kerbin Place another maneuver node at the next ascending/descending node and use it to match inclinations. At the same time use the other adjustments to make sure you get an encounter Some time before your encounter you can use another node to fine tune your arriving orbit for aerobraking. Using a nuclear engine you should easily be able to pack a spare 500 delta-v.
  10. Planning Look up the Delta-v required to get to Eve from the chart on the wiki It says 4550ish to launch from Kerbin and then just over 1000 to get to Eve Either work out with a pen/paper/calculator/spreadsheet a design for a rocket with the required deltaV Or, install a mod like mechjeb or kerbal engineer redux Building an asparagus staged rocket will help get the delta-v up
  11. High eccentricity of your target (or departure) bodies orbit can have a similar effect. The body won't be where the chart expects or travelling at the expected speed. This tool http://alexmoon.github.io/ksp/ should give a much better estimate which takes eccentricity and inclination into account.
  12. The vast majority of your transfer will be done in the sunlight, only the initial burn will be done in the shadow of Kerbin. If you using Ion engines then that will be a bit of a problem, but if you are trying to boost something large with ion engines you are going to have issues anyway. My advice would be to switch to a nuclear stage, or if you really like long burns use the ion engine to spiral out without worrying about where your pe/ap are until you are nearly going fast enough to escape and then time your final burn to send you off into kerbol orbit in the right direction.
  13. Why do you think it loses that velocity? Most rockets are launched on an easterly orbit to take advantage of that rotation.
  14. Hmm, yes I have always just used the answer from the wiki that does appear to be wrong. I'm surprised now that my rockets have always made it to orbit.
  15. They are using mods, probably mechjeb or mechanical engineer redux. Both of those provide several information windows. If you only want fuel you can see it by clicking the resources button top right.
  16. The effective ISP of multiple engines firing at once is (ThrustEngine1 * ISPEngine1 + ThrustEngine2 * ISPEngine2 ...)/(ThrustEngine1 + ThrustEngine2 ...)
  17. Bit late, half the engines have broken off
  18. Here it is when I landed After unloading the crew Note that all the legs have now sunk into the ground The view is currently focused one one of the mainsails which is no longer attached
  19. Sadly I saved over the quicksave and was for some reason creating backups of the persistance file instead. I'll try to post screenshots tonight
  20. The flagship of my space agency is sinking. I landed fine on a piece of flat, gently sloping land near the sea, a bit bumpy but nothing was broken. I EVAd one kerbal, I switched back for the other and the landing legs sunk into the terrain to leave me resting on the engines. I EVAd the second kerbal and switched back to the rocket. One of the engines fell off. Now every time I switch to the rocket it sinks a little lower and another piece falls of. Unfortunately I seem to have backed up the wrong save file. Does anyone have any ideas of how to restore a working rocket? I am willing to use any method necessary.
  21. mechjeb for smartass Kerbal alarm clock KSPX for a few more parts - (the 2.5m nerva in particular)
  22. You want to download the subassembly loader mod. It allows you to save part of an existing rocket and then load it later to attach to a different rocket. You can't do it with stock ahh ninja'd by someone who actually found the link.
  23. my post here Calculating-interplanetary-delta-v Does a run through calculating the figures for anything without an atmosphere. For bodies with an atmosphere it is much harder.
  24. Working out the perfect launch window is pretty hard, I looked into it and it seemed to come down to equations that weren't solvable algebraically. I think what people IRL do is draw up lambert pork chop diagrams and visually look for a minimum.
  25. Another problem with Moho is that the eccentricity of its orbit means that the phase angle calculations done by protractor, mechjeb etc can be significantly wrong. At different points of its orbit moho can be traveling at very different speeds so it won't be where those tools based on circular orbits predict. I ended up setting an alarm for 3 days before the simple phase angle and then using a maneuver node to attempt to create a transfer. It was miles out so I waited for 12 hours and tried again, and again, and again. In the end the true windows was 6 days after the theoretical one. You want a transfer that just kisses the orbit of moho, and you want to do it at a time when moho will actually be at that point. If you come in to moho with any angle other than perfectly parallel to it's motion you end up with a massively more expensive capture burn.
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