"Safe-Zone" Delta-V for orbits and such.

[Tex]

I have never been the best rocket builder. I'm not saying I've done no advanced procedures; I've done docking, assembled small stations, and even landed on both of Kerbin's moons. The one thing I have trouble with; my LAST hurdle in KSP is getting to other planets.

I can read Delta-V maps fairly easily, and I just want to know how much extra Delta-V I should have my rockets reach in order to get to other planets with the technology I want in tow. It would also help to be able to make more efficient Kerbin system rockets.

How much should I have as spare Delta-V for different operations? I could theoretically land on Duna with a rocket of only 7360 m/s of Delta-V, even though I know in actuality that would neeeeeever happen. I've built 12 km/s rockets that only get to interplanetary space.

Edited January 7, 2014 by Maximus97

[Mr.Rocket]

Make sure you do you planetary burn before you exit kerbin's SOI, that way, you get a small boost from kerbins gravity. I understand what you mean about inaccuracy in maps. I built a rocket with lander that should've been able to get to Eeloo orbit with half of it's fuel left, but it only has an eighth soooo.... I would recommend at least a thousand if not more delta-v extra than what it says for any mid-course maneuvers. Also, use something like kerbal alarm clock to get the launch windows to other planets right to use the least delta-v possible.

[Guest]

I generally allocate anywhere from 5% to 15% extra delta-V for the inevitable corrections. 5% extra for around Kerbin operations because it's so easy to be precise and pick up the Kerbals in the case of a mishap, and 15% for trips to Moho where you never can be sure how hard you'll have to brake.

I only use delta-V maps for landing guesstimates; I find them a bit too optimistic regarding everything else. Alex Moon's launch window planner and other such tools give much better values.

[Specialist290]

I can pretty reliably make orbit on ~4500 delta-v, so I usually fine-tune my launchers to have around that much (and usually try to plan for the last stage to be capable of deorbiting itself -- gotta keep space clean, after all).

For interplanetary transfers, I generally try to give myself a buffer of ~10-25% extra of what the delta-v chart says, for miscellaneous corrections. Similarly, for landers, I'll aim for ~25-50% extra, since I take the "slow and steady" approach to landing most of the time rather than relying on hair-trigger suicide burns. For takeoff after landing, I'll typically add another 10% extra or so (since it's not as critical to have a buffer as it is for landings).

Of course, these are very approximate guidelines, and sometimes I'll use more or less buffer depending on how confident I am with a given target.

[Tex]

Thanks for all the reccomendations! I'll definitely be taking these into account.

[capi3101]

I generally shoot for about 125% of the indicated delta-V, and then thanks to the method I use to determine the number of "FL-T100 Equivalents" required I often wind up with a little bit more than that. Sometimes its enough. Sometimes it isn't.

I have found that the latest iteration of the delta-V map is a bit more accurate than previous versions; the nice thing about it is that it also includes the amount of delta-V required for orbital plane changes. Every bit of info helps. I'd link it but I don't remember where I first saw it.