Quick question about DV on the map on the Cheat Sheet on the Wiki

[Joe_Bender]

http://wiki.kerbalspaceprogram.com/wiki/Cheat_Sheet

Tell me if I am reading this map correctly.

If I want to go from Kerbin to Jool and obtain a orbit, I have to have the following DV.

4550 m/s to launch and obtain Kerbin orbit

950 m/s + 965 m/s (1915 m/s total) to get to Jool

2630 m/s to slow down and get into Jool orbit

I am not sure about the DV needed to fly from Kerbin to Jool. Would it just be the 965 m/s from Kerbin intercept to Jool section only?

And what numbers do I use to get back? The same numbers, only in reverse?

965 m/s from Jool to Kerbin and another 950 m/s to slow down enough to enter atmosphere? Or just the 965 m/s?

[Boffinbox]

950m to reach the edge of kerbin's SoI and just break free

965m to get from that kerbin orbit height to jool orbit height

as for getting back that all depends on where you're coming from. it wont necessarily be 2630 to speed up and get onto kerbol orbit because you might be leaving from, say, laythe.

once reaching kerbol orbit again, it's 965 to get back. you can aim that 965 to put you onto a collision course for kerbin (and you'll lose your velocity to the atmosphere so that's fine)

[Joe_Bender]

Thanks!!! That helps me alot in planning on my ship builds

[Dave Kerbin]

The 4550 gets you into orbit around Kerbin

The 950 gets you into orbit around the Sun (at almost the same altitude as Kerbin, either a bit above or below but you need to zoom in to see the difference)

The 965 gets you to Jool's altitude above the Sun where if your course was right you'll have a Jool encounter - just like when you get a Mun encounter and enter its SOI. You'll have a PE with Jool but no orbit, your path will terminate with an 'escape' back into Sun orbit.

The 2630 turns your encounter into a 150km orbit above Jool.

Keep in mind a few things. The 950+965 to get you to Jool assumes that Jool and Kerbin are in the ideal position for a transfer. If Jool is on the other side of the solar system (or worse it is 'behind' Kerbin) you'll need more. You might try the calculator to see your transfer window. It shows a color coded graph of how much delta V is required if you leave on a certain day and aim for a certain travel time: http://alexmoon.github.io/ksp/

The 2630 for Jool orbit is if you use thrust alone to slow down. Jool, and other planets with an atmosphere (Kerbin, Eve, Duna) can take advantage of aerobraking. Before reaching Jool (maybe just after you enter its SOI) you burn a tiny amount of delta V to nudge your course over so that you'll skim Jool's atmosphere. The atmosphere will help slow down your ship for free, though be careful not to go too low or you will unintentionally 'land' on Jool. After aerobraking you'll be in an orbit with the PE inside Jool's atmosphere. Once you swing out to the AP you perform a small burn to raise your PE to a stable orbit. This can reduce the delta V cost substantially. Jool also offers the option of using one or more of its moons for a gravity assist to brake, that's a lot more complex.