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Found 12 results

  1. I wanted to design a heavy SSTO that carries a large amount of crew and has an ISRU with drills in the back for refueling. Without any fuel or engines, it weighs around 70 tons. I recently watched a video by Mark Thrimm that gave multipliers that you could use to determine how much liquid fuel, rocket fuel, and RAPIERS you need based on your dry mass. I would use those multipliers for this purpose, but they only give enough fuel to get to LKO and then be able to de-orbit. I want this SSTO to be able to, at the very least, be able to get anywhere in Kerbin's SOI, and potentially to Duna, which requires significantly more delta-v than LKO and de-orbiting. Does anyone have different multipliers to use, or at the very least equations that I can plug stuff into in order to find how much fuel and engines I need? On the other hand, does anyone have any better methods or comprehensive tutorials they could point me to? Just getting started into SSTOs and am still trying to figure it out. Any help is appreciated! Note: I have KER if there is anything there that can help with calculations, just point me to the right submenus and clicky things. Thanks!
  2. I've built a big ship for a manned travel to Mars.It's powered by 3 nuclear engines with Liquid Hydrogen as fuel.The complessive burn time is around 2 hours and the fuel is just enough to the whole trip to Mars and return ( no errors or DeltaV waste possible).So , what's the best way to save as much DeltaV as possible in maneuvers by doing them efficently?Are there any rules that I have to know on how to save fuel? The ship plays a lot on throwing away empty tanks ( life support and fuel), squeezing DeltaV to make the vehicle lighter.Start mass : 600 tons. End mass (from Mars to Earth): 150-200 tons.
  3. Hi guys, So I was wondering, Because I have already went to the mun and minmus once (new career save, don't ask), I was wondering how much DeltaV it is to Ike and back. I've already been to other planets in my other Sandbox save, but never Ike. Also, is an Eve gravity assist a good idea? I have a Duna window in 71d, and an Eve window in 1y 120d. I also have critical contracts lying around, won't they get expired? Regards, Mabdi36
  4. I'm planing a manned Jool mission for my career save. The focus will be on extracting as much sweet, sweet science as possible from the Jool system before returning home to Kerbin. I'm going to use a NERV powered main mothership with 3 daughter landers to cover all the moons. (The Tylo lander will be an unmanned one-way trip!) Since this will be my first visit to Jool, I'm not sure what to expect for dV requirements after I capture into the Jool SOI. For a conservative estimate, I could simply add up all the numbers from the KSP delta-V map to get intercepts with each moon including the plane change amounts. This assumes (1) that the parent body will be Jool every time (2) no gravity assists from the other moons and (3) no daughter vehicles. With this in mind, do people have a ballpark number for the delta-v requirements to encounter all Joolian moons? I'm looking for rough estimates as a gut-check for my planning purposes, preferably from those who have done similar missions. I should also mention that I'm not planning to do any resource extraction, but I might need to if the dV requirements are too high.
  5. DT Vista Engine Losing Thrust

    So I have built a vessel to carry my crew to the Jovian system in KSP. I am trying to leave the Kerbin system with a DT Vista Fusion Engine, but I keep running into the same problem over and over. Out of the blue, my thrust drops to 0. I check Kerbal Engineer and it says that my fuel is burning and all other resources are being consumed as normal. Check the engine itself and it says it has 600Kn of thrust, but my orbital speed isn't changing at all. There is a constant supply of power coming from the Nuclear fusion generator, keeping the power above 2.5Gw. This isn't happening right when I start my burn either, I will use 1,750DV in a certain direction with perfect output from the engine, but after that it just stops, with 250 more DV required to finish my burn correctly. I have been looking over this all night and I cannot for the life of me figure out what is causing this constant failure in engine output. Any advice? Anyone else seen this weird bug?
  6. So, I've been building a series of different whip probes, and was wondering what kind of results other folks get from this style. This probe's purpose is to leave at bad transfer times, "Whip" around another SOI for a flyby contract (without orbiting), then get itself shot home ASAP. To do this, I'm aiming for triple, if not quadruple, the standard dV necessary for the transfer, and I want solid TWR (0.4+)so that the burns can be made with reasonable accuracy and not having to 'wind up' an orbit. The best I've been able to fit into my 140 ton limit (255 parts, but I don't even get near that) has been between 11,500 - 11,800 m/s d/V at launch if I want decent takeoff TWR. Here's one variant with some of the staging a bit off (I've been goofing around since then): EDIT: Due to some confusion as to the purpose of my original image, this is one that has its staging correct and works as an example instead of a stripped down version showing most of the parts in play. It runs at 12,909 d/v on the pad and hits orbit with about 9,700 d/v left after ditching the mainsail and finishing its burn on the Terriers. There's an entire array of Oscars, Ants, science gear, antenna, and other stuff inside the fairing. Now, I realize Nukes change the landscape completely, but I was wondering who else had come up with purposely over-engineered vessels like this with limited tech so we can compare notes.
  7. Hey everyone, I have a quick question regarding Delta V. A lot of times my rockets wont have enough to make a full burn, and I'll have to use the next stage to complete it, which puts my whole mission out of whack. Any tips for getting more Delta V? Thanks!
  8. Jool 5 Tylo Landing

    Im attempting to build a tylo lander, and im wonder a few things about it. 1. What kind of TWR should i have for my decent stage 2. How much Delta v would it take to land, and return to LTO (Low Tylo Orbit) 3. I am using a Ion Tug to de-orbit my lander, so I don't need to worry about that.
  9. Alright. Let me make on thing clear. I know how to calculate delta v. I have the math done and burned into my head. But I cam across a problem, how do I get the ISP, for different engines on the same stage? So say if I have a "MainSail" and a "Thud" sharing the same fuel on the same stage, how to I get the ISP to put into my formula?
  10. RCS delta V?

    Hi, in ksp 1.1+ is there any way of guessing how much dV can your RCS thruster give? I believe that neither vanilla nor K engineer can do it? Or do they?
  11. In the Advanced Construction training exercise, Wernher von Kerman gets the player to reduce the Thrust Limiter on the "Swivel" to 65% and on the two "Hammer"s to 50%. I know from experience that this will reduce the TWR and increase DV of those engines but there is no indication in the VAB that this is what is happening. Why not 75% or 50% for the "Swivel"? Its effects are apparent in the next Training exercise "Go For Orbit" in that it means you can keep the throttle on max rather than adjusting it during launch to keep your speed below the burn limit caused by atmospheric drag, but if it's training it should explain why it's getting the player to do something.
  12. Transfer Energy

    Last week there was a thread created that discussed the basic requirements of deltaV required to get into various positions of the moon. Other than the launch variables the statement was made or asked if deltaV tables was the best way to handle this. I looked at the from an energy perspective, first off I need to add that the classic formula for calculating delta-V between two circular orbits is - SQRT(u/r0) for the first burn (r is r0 in this case in the wiki image, ignore the v = ) r can either be an apoapse or periapsis and SQRT(u/r1) - (r is r1 in this case in the wiki image) for the second burn. r can either be an periapsis or apoapse The perfect energy requirement equal to the is close to this at in the case of the lowest and highest eccentricities (e = 1) but in the middle ranges it is considerably different. The basic problem is that elevation of a circular orbit neccesarily requires two burns. During small burns the change of velocity is small and as a consequence little momentum is lost. In changing to very eccentric orbit much momentum is lost, but the dV required to establish the second orbit is small fractional to the energy required to create the transfer orbit. At minimum escape velocity its zero. In eccentricities (e) of transfer orbits around 0.7 (e.g a geosynchronoous from LEO transfer) have substantial inefficiency because considerable momentum is lost as the satellite slows to its apoapse at which it needs to burn. So for example a station keeping burn is perfectly efficient, and also a escape orbit (minimal) is perfectly efficient (but because of N-body problems more or less a theoretical exercise) The energy requirement works within tolerances if the correction factor for eccentricity is provided dV (total)/((1-e)+LN(1+e^1.9)), up to about e=0.75 but becomes inaccurate after this. Its not perfect. I tested this with a number of orbits, a is irrelevant the error is a function of e. This means without using a table one has a minimum requirement for a single step energy plot of knowing e as well as initial radius and final radius. Its not hard to calculate e but in creates also a two step operation. Ergo the OP is correct, the two step dV plots are as simple as any other means of plotting the dV requirements of an orbital change.