Kerbin-Orbiting Interplanetary Booster

[NASAHireMe]

I'm regularly performing interplanetary missions now, mostly to Jool (establishing stations around Laythe and Tylo, a swarm of probes just for fun, etc.). I've found the most tedious part of gameplay now to be the Kerbin-ejection interplanetary burns.

I hate burns that take more than 5 minutes, even with forced 4x acceleration. Mostly because I generally start in a 100km orbit and the time it takes to perform a 9 minute burn with 2 LV-Ns on a big orange tank + payload can significantly alter the true trajectory, if not accidentally enter Kerbin's atmosphere and get destroyed.

For my latest flotilla, I used the 'multiple burn' approach, dividing the total Joolian transfer delta-v of about 2000m/s into several smaller burns at periapsis. But each time this raises the apoapsis and throws off your transfer window by delaying the final ejection burn (admittedly, not a big deal for Jool, but may be for other destinations), and you have to be careful that you don't raise your apoapsis so much that you exit Kerbin's SOI. All told, this is a MASSIVE pain to execute.

What's a good solution to get the 2km/s burn done in one short, blissful burn?

The solution I've come up with is to use an 'interplanetary booster' that consists of a large docking port, an orange tank, and a Mainsail that I connect to the main ship and use to give me that 2km/s ejection burn. Once I achieve a Jool transfer orbit, I immediately undock the ship, turn the booster 180 degrees and burn back into a Kerbin orbit (with aerobraking assistance) so that I can use it again.

Does anyone else use this method? It takes a lot of fuel, but gives you a quick and painless interplanetary burn. But then you also have to take the time to bring the booster back into a Kerbin orbit, so probably the overall time savings are minimal.

[Torquemadus]

My current method for departure burns it to stage part way through the burn. The stage used to begin the burn is left behind in a highly elliptical orbit around Kerbin, I then aerobrake it back into LKO.

[Empiro]

I've considered a similar approach as well. I think that it's more of a cost-savings issue than a time-savings issue since as you said, you need to bring things back (and re-fuel it, and dock it, etc.). I think the thing I'd do differently is that I'd use this engine just for raising the AP but still within Kerbin's SOI. This way I don't have to turn around and burn -- I can just wait for AP and put myself in the atmosphere for aerobraking using very little delta-V. Otherwise, you'd have to slow down quite a bit (~1000 m/s) if you're going somewhere like Jool.

I think that long burns will get a bit better in the next version, since we'll have the piloting assists that do things like point your craft toward the maneuver node, so you can just do a 4x warp and not have to keep doing corrections.

Edited December 12, 2014 by Empiro