Whats the best way to escape Kerbin?

[Tigermisu]

In order to save some delta Vs....

(Also, to leave Kerbins SOI and orbit around the sun)

Edited April 27, 2013 by Tigermisu

[UmbralRaptor]

It's the same as a minimum ÃŽâ€V orbit (use craft design and/or throttle to stay near terminal velocity, begin gravity turn at ~5-10 km, go east, keep your angle of attack down, be horizontal by ~30-40 km.)

[SkyRender]

That really depends on what you're trying to do.

If you just want to get a relatively small payload to orbit (and don't mind the steep-as-a-cliff learning curve), spaceplanes are the way to go. It costs far less fuel than a straight-up rocket to do it that way and makes re-entry much smoother as well.

If you want to get any sort of payload bigger than a peanut into space, however, rockets remain your best bet. Though there is a strange sort of cross-design compromise possible in KSP right now that you can't do in real life: link up a series of jet engines around the base of the rocket, and augment your lift with them. This generally works pretty well for mid-sized payloads. Look up Scott Manley's Reusable Space Program on YouTube to see a fairly good example of this in action.

As for exiting the atmosphere, I find the best method is to generally keep thrust fairly light in the lower atmosphere (no more than 100m/s below 2000m, 160m/s below 6400m, or 240m/s below 10000m), then perform a pitch-over at 10000m 45 degrees towards east and throttle up. From there, I monitor distance to apoapsis more than anything, keeping towards prograde and also aiming for 50s to 1m10s to apoapsis at all times until apoapsis is 60000m. Once I'm that far, I start to ease back on the time to apoapsis, until it's at 70km and I'm nearly at it. Circularizing is laughably easy this way, and the whole process tends to take just a hair shy of 4000dV.

Edited April 27, 2013 by SkyRender

[tommygunyeah]

Depending on your weight

I usually go for a burn till 10km trying to stay within terminal velocity.

Then turn 45° East and try to keep on my prograde after it passes that 45° mark.

Get my Ap above 70km and then do my orbital burn just before my Ap.

[llamatoes]

I use my engines to escape from kerbin's SOI

[eurybaric]

That's fine and all... But what about a Mun slingshot? worth it?

[foamyesque]

That's fine and all... But what about a Mun slingshot? worth it?

Sure, but it makes aiming where you go afterwards tricky.

[UmbralRaptor]

That's fine and all... But what about a Mun slingshot? worth it?

Yes, if:

1) You've *very* precise and going to Minmus.

2) You can pull off precision levels comparable to real world space agencies, and are looking for a challenge, even though in KSP this can be solved with an extra few dozen to few hundred m/s ÃŽâ€V.

3) All you care about is minimizing ÃŽâ€V to Kerbin escape (so where you end up doesn't matter).

Otherwise, not so much.

[SkyRender]

Gravity assists are a messy business. You not only need to hit the incoming trajectory around the Mun just right, but it needs to be slingshotting you in the direction you want to go AND the planet you're trying to reach needs to be in phase too. And even at that, you probably won't save that much delta-V in the process since you're going to have to do course correction post-slingshot without the benefit of the Oberth Effect.

[magnemoe]

Gravity assists are a messy business. You not only need to hit the incoming trajectory around the Mun just right, but it needs to be slingshotting you in the direction you want to go AND the planet you're trying to reach needs to be in phase too. And even at that, you probably won't save that much delta-V in the process since you're going to have to do course correction post-slingshot without the benefit of the Oberth Effect.

I have got it to work some times, mostly out of luck. Note an return from Minmus while low on fuel/ rcs only can be helped by Mun, Jool slingshot can take you to Laythe without Jool aerobrake and then raise orbit for an Laythe intercept. Note Laythe atmosphere is thinner than Kerbin and mechjeb mess up with +6Km/s incoming but its fun an Jeb loves it.

[CalculusWarrior]

I once used a gravity assist around the Mun to get me to Eve, it was mostly luck though, and I think I did end up saving only ~50-100 m/s of delta-v. Though it did look amazing to see the Mun come up and then fly away as I was ejected from Kerbin's SoI!