First steps beyond Minmus -- Sun SOI and Eve/Duna

[NERVAfan]

1. How do I plan out a trajectory that gets me into the Sun SOI and then back to Kerbin SOI? I would like to get crew/EVA Reports from "High above the sun" without stranding kerbals (and return materials bay/goo also).

2. Is Eve or Duna a better first target? Duna has much less inclination (according to the wiki). http://ksp.olex.biz/ says it doesn't take inclination into account; how do I make sure to account for that?

Edited March 30, 2014 by NERVAfan
"answered" tag

[Rakaydos]

Get a trajectory that just barely exits Kerbin's SoI, then turn off your batteries to save power. When you exit you will have almost no velocity relative to kerbin, so you can do science, turn your batteries back on, and burn straight back to the blue dot until you get a kerbin SoI encounter.

[Taki117]

To answer your second question: Duna is a much better target, you really don't need to do an inclination change but you can if you want.

[Geschosskopf]

1. How do I plan out a trajectory that gets me into the Sun SOI and then back to Kerbin SOI? I would like to get crew/EVA Reports from "High above the sun" without stranding kerbals (and return materials bay/goo also).

For "High Above Sun", just set up a node that gets you just barely to escape velocity and no more, parallel to and going in the same direction as Kerbin. As soon as you cross the SOI, do your science, then burn a bit retro to fall back into Kerbin's SOI.

"Low Orbit at Sun" is more challenging. You need to burn retrograde to Kerbin into an elliptical orbit with a Pe < 1,000,000m to get that. That's the easy part. The hard part is getting back home again. It will typically be about 5 orbits later before Kerbin is there when the ship comes around. This trip takes loads of d-V. A much better pilot that me, who took the time to calculate and then execute a perfectly synched Kerbin rendezvous 5 orbits later, did it with 5000m/s. I just went for it without any planning and it required 8000m/s.

2. Is Eve or Duna a better first target? Duna has much less inclination (according to the wiki). http://ksp.olex.biz/ says it doesn't take inclination into account; how do I make sure to account for that?

It depends on what you want to do when you get there. Getting to/from Eve and Duna requires pretty much the same d-V and both are pretty easy targets to hit. In order of increasing difficulty, I'd rank the various things you can do once at Eve and/or Duna as follows:

1. Dropping 1-way probe landers on Eve. No need for return fuel or even landing engines, so tiny little rockets suffice for this.
   
2. Dropping 1-way probe landers on Duna. Slightly more complex as you have to work on the landing.
   
3. Orbiting and returning from Eve or Duna, pretty much a wash.
   
4. Orbiting Duna, landing on Ike, and returning.
   
5. Orbiting Eve, landing on Gilly, and returning (takes more fuel as is a longer trip and Gilly has a big inclination difference)
   
6. Landing on Duna and returning.
   
7. LOTS of other things you can do in the game
   
8. Landing on Eve and returning.
   

[BudgetHedgehog]

1, Perform a Minmus burn as usual, but as you reach it's altitude, throttle down so you don't overshoot. As soon as your orbit exits Kerbins SOI, cut throttle and wait. You should only be a few m/s over escape velocity. Once you're in solar orbit, do stuff. When you're done, turn your vessel so it's pointing straight at Kerbin and throttle up. Ideally, you won't be in the Sun's SOI for more than a few minutes so Kerbin won't be too far away. Either way, point and shoot. When your map says you're going to re-enter, throttle down and wait until you're back into Kerbins SOI. Then, make any orbital changes necessary to put your perikee at around 30km for aerocapture. Your craft doesn't need to be anything special - anything capable of landing on Minmus will be able to do this.

2, I'd say Eve because of the thick atmosphere and larger gravity well, but it really does depends on whether you're planning on coming back. If you are, aim for Duna - an aerobrake is easier (don't forget F5 though!) and you can lift off pretty easily too. If it's a one-way trip, head for Eve. Gilly can provide some pretty good Science and it's **** easy to land on.

An inclination change in Solar orbit will cost you about 300m/s dV which, if you're piloting interplanetary vessels, isn't that much really.

[cantab]

2. Is Eve or Duna a better first target? Duna has much less inclination (according to the wiki). http://ksp.olex.biz/ says it doesn't take inclination into account; how do I make sure to account for that?

If you're still early in the game calendar, the first Duna window is around day 60. There are transfer windows for several other planets around that same time too. The first Eve window though isn't until day 150. So, for most mission types, I'd plump for Duna first.

[Tank Buddy]

I'm pretty sure Duna is easier not only because of less inclination (I never noticed a major difference in DV requirements since an Eve ejection burn from Kerbin takes less than one to Duna), but because it takes less DV to maneuver around the system.

[NERVAfan]

Thank you, that covers everything I was looking for...

[NERVAfan]

OK, did the high orbit Sun and return thing and it worked great, thanks again!