Delta v required to get to laythe and back?

[Meso Relic]

Provided that transfer is near-optimal without aerobraking. Is it still possible to safely aerocapture around laythe from Kerbin?

[Jesrad]

Indeed it is, and you can do it prograde or retrograde, too I used to do it with Laythe retrograde relative to Jool for sport, back in 0.23 - you come in at 8000 m/s. That might not be safe anymore with the new aero model, though

IIRC you can get from LKO to Laythe atmosphere intercept for as little as 2100 m/s.

Edited June 11, 2015 by Jesrad
atmosphere, not amtosphere

[Mastikator]

http://wiki.kerbalspaceprogram.com/images/7/73/KerbinDeltaVMap.png

LKO -> KSOI -> Jool Intercept -> Jool Orbit -> Laythe Intercept -> Low Laythe Orbit

950+980+160+930+1070 = 4090m/s Delta velocity

Less if you use gravity assist and aerobreaking.

I would add personally 25-50% extra delta V because I always make big mistakes and forget to save and don't do things optimally. (and also because bigger rockets are cooler)

[Jesrad]

Considering you'll use a single burn at LKO, you have to recombine the costs of each step of the way. I get 2868 m/s without aerobraking on arrival, accounting for the proper Oberth Effect (see link in my sig).

[Edit] Hmm I get 4049 m/s without the aerobraking at the end, actually. I think that's still too high compared to actual trips done.

Edited June 11, 2015 by Jesrad

[Jouni]

Here are some actual numbers from a reasonably efficient mission to Laythe with a high-TWR ship.

• Transfer burn from a 120 km orbit to Jool: 1947 m/s
  
• Course corrections in interplanetary space to get a direct encounter with Laythe: 58 m/s
  
• Course corrections in the Jool system to get a good encounter with Laythe: 71 m/s (I made some mistakes)
  
• Circularization to a 100 km Laythe orbit: 998 m/s
  
• Transfer burn from Laythe orbit to interplanetary space with periapsis at Kerbin's altitude: 985 m/s
  
• Plane change in interplanetary space: 60 m/s
  
• Course corrections in interplanetary space to get an encounter with Kerbin: 52 m/s
  
• Circularization burn to a 90 km Kerbin orbit: 1954 m/s
  

The totals were 3074 m/s from Kerbin to Laythe, and 1097 m/s to 3051 m/s from Laythe to Kerbin, depending on how much you dare to aerobrake.