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Found 15 results

1. ## How can I get this SSTO to orbit?

So, I just created a new SSTO that has about 5,000 meters per seconds of deltaV, but I can't get it into orbit. It goes well until I hit the higher atmosphere, and then it screws up. Can someone please help? Craft Image
2. ## ∆V - What, Why, How.

I have decided that after spending almost 600 hours in the game (595, should be 600 by the time I'm done tonight) it's finally time. I have never learned ∆v. All I know (and this could even be wrong, i'm really quite clueless) is that ∆v is the amount of acceleration/deceleration (although deceleration is acceleration technically) a ship or stage of a ship (or anything really) is capable of with it's current mass, fuel, fuel efficiency, and thrust. please, if I am wrong, correct me. what I would like to know is how to properly calculate the ∆v needed to make it into a specific orbit, how ∆v can be calculated for any given ship you may make, and anything else important to know about ∆v. I am by no means a noob at KSP, but also by no means an expert, to give you a feel for where I'm at in terms of ability, in career mode I have landed Kerbals on Duna and Eve, crashed a probe into Eeloo, done single ship return missions to both Minmus and Mun, I have landed a class C asteroid on Kerban using only 1 ship, and in terms of aircraft, i have flown around Kerban using a single drone without refueling, and landed back at KSC (technically I plowed into the hangar at about 450 m/s as a celebration, but i've landed that exact drone 4 other times out of 5 attempts, so I could have landed it if I wanted to). I never really bothered with ∆v because I was usually able to ignore it, and just build the ship so that it looked like it would be good enough to make the trip, then I would launch under the personal decision that regardless of the failure or success of the mission, I would revert the flight after (I called these flights my simulator flights, and I considered them to not be real, that way it was a test, to see if my ship could do what it needed to do) then after a successful simulator flight I would launch for real, and regardless of success or failure, I would not revert after the flight. using that method ∆v wasn't ever NEEDED. With the addition of certain ∆v based aspects of the game in the latest update, I decided the time had come for me to finally learn how it works, and start applying it to my space program. Many thanks, -Water
3. ## Hello! Help on transfer from Eve to Moho

Hello! I've got some problem. My plan was to take almost all of my kerbals on a trip across the system to level them all up. The first point of the travel was Gilly (Eve's moon) because it so happened, that a transfer window coming right about then. From that place, the next closet window was to Moho. But what I didn't do, and what I should have done, was to check the amount of delta V , that is needed to perform that maneuver. Thus while I'm parked in the south pole of Gilly I have 3439 m/s delta V plus around 200 from emptying monopropellant tank and converting ore. I figured that the best moment to get ejected from Eve's system comes In 8 days, because then I almost don't need to correct my trajectory for Moho's orbit inclination. You can also see the way how I get out of Eve's system here. Opposite to the planet's direction of orbiting the Sun. That seems to be the most optimal. That's like the transfer trajectory between planets looks like: And this is the moment when I close the orbit around Moho (not even landing): I reckon that I would need another thousand more to land on the surface. Concluding, in total I'm somewhere around 1500 m/s to short on delta V to pull that off. My question to you guys is... do you see any way of making it work? Maybe some better way of utilizing oberth effect or any tricks of that kind? Thought that there maybe are some space veterans who had some advices. I know I could just refill the fuel in the mid flight with KLM, but I would rather wait for a window to other planet than using cheats. Regards, T
4. ## Delta V and Boosters

Hey everyone. So I'm struggling a bit both with getting satellites to orbit and to make airplanes that can fly high altitudes. Last night I was googling for some tips and tricks and I came over a thread with someone posting a picture of a plane he made. https://m.imgur.com/Q7J5cyL As you can see in the pic his thrust limit is 36 and he woops out a smashing 23.4 k delta V?!?! I tried to make roughly the same model but I get nowhere close to that! Thrustlimit set to around 1 and I get something like est 8 min burn. Ofcourse that thrust is so small even a light aircraft would never lift. How is this possible? How can he have a twr if 1.02 and an estimated burn of 14 hours??
5. ## Long burn times ship [RO/RSS]

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.
6. ## How much DeltaV to Ike and back? (OPTIMAL DELTA)

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
7. ## dV budget for Jool system operations?

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.
8. ## 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?
9. ## High dV rockets without Nuke/Ion and limited tech ideas

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.
10. ## Ways to add more Delta V?

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!
11. ## 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.
12. ## Delta V calculation help

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?
13. ## 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?
14. ## Training - Advanced Construction - Missing Information

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.
15. ## 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.