I have a craft stuck in a solar orbit, how do I get it back to Kerbin?

[yorshee]

I've been playing lots of career mode lately and I was doing a mission to get lots of Science from Moho. I planned to get into a low orbit so I could get the low space Science for Moho as well as the high space Science. Long story short I didn't have the delta-v to get into orbit, so I got the high space Science and basically panicked and tried to tweak my trajectory to get back to Kerbin.

That didn't work so now I'm in some weird orbit where the apoapsis is roughly where Kerbin orbits, and the periapsis is slightly closer to the Sun than Moho. I only have around 200m/s of dv left, and no matter what I try to do to the trajectory, I just can't get back to Kerbin. I even left it for a while to go do other missions and hoped that eventually Kerbin and the craft would miraculously intercept one day, but it never happened.

What should I do? The craft has a docking port on it so I could send a load of fuel up there, dock it, refuel, undock, and then I would have the dv to get back to Kerbin, but I don't know how easy that would be. Alternatively I could send an unmanned crew capsule and transfer the crew over to the capsule and then get back home that way, but I sort of want the Science you get from recovering a craft from Moho.

Any suggestions? Poor Valentina has been stuck out there for 3 years now.

Edited May 3, 2015 by yorshee

[Requia]

Look at hitting eve or moho, should be easier. I've seen grand tours done with very little dv by using gravity wells to change angles.

[Guest]

You could do that, or just cover the evidence up and bury the hatchet.

[Windspren]

H-y-p-e-r-e-d-i-t

[Anquietas314]

H-y-p-e-r-e-d-i-t

... is cheating

You could try this:

1) Set Kerbin as your target, set a node at your current apoapsis.

2) Right click that node and keep moving it forward an orbit until your closest approach to Kerbin is reasonably close.

3) Once you have a decent closest approach play with the node until you get an encounter.

Chances are it'll take several orbits to get Val home, but if she's been out there 3 years already... another 3 probably won't make much difference

[yorshee]

H-y-p-e-r-e-d-i-t

I'm running a strict no-cheating policy on this save game! No debug menu either. I wanted this to be the first save file I ever did properly with no HyperEdit. It has made my accomplishments a lot more fulfilling and I don't want to ruin that. If I manage to get the crew back to Kerbin by myself then it'll be the first rescue mission I ever did without cheating, too - I don't want to miss out on this accomplishment.

Look at hitting eve or moho, should be easier. I've seen grand tours done with very little dv by using gravity wells to change angles.

Would that not require Eve/Moho, my ship, AND Kerbin to all align perfectly? I've never done any gravity assists before, so I dunno how it works.

... is cheating

You could try this:

1) Set Kerbin as your target, set a node at your current apoapsis.

2) Right click that node and keep moving it forward an orbit until your closest approach to Kerbin is reasonably close.

3) Once you have a decent closest approach play with the node until you get an encounter.

Chances are it'll take several orbits to get Val home, but if she's been out there 3 years already... another 3 probably won't make much difference

I'll give this a shot tomorrow Thanks!

[Alias72]

well if your still on your escape trajectory from kerbin then technically you could just wait for your orbits to intersect again in a couple of centuries...

[THX1138]

You might not have enough to be captured by Kerbin. I think you're going to have to send a craft to deliver fuel. I think ideally you're going to want to move through the Kerbin atmosphere or else get gravity assist to slow down from the Mun.

[impyre]

This gets *way* more difficult after you've been outside the SoI for awhile. I got a "sun flyby" contract and used valentina. I escaped on a solar radial-in direction, got just outside kerbin soi, then burned radial out (back toward kerbin) to get back in. This works well with radial-in/out escape paths because you aren't changing your orbital period relative to kerbin... (not much anyway), whereas if you escape prograde/retrograde, getting back can be difficult... because once you change your orbital velocity relative to kerbin, you start falling away (both in terms of phase angle and altitude). I recommend radial changes for short there-and-back trips to solar soi. At the very least you can regain encounter in half an orbit with very little dV.

- - - Updated - - -

To answer your original post, with 200dV and such an elliptical orbit, the best option is to simply wait a year or two for re-encounter. Highly elliptical orbits spend the vast majority of orbit time at their apoapse... in contrast kerbin will be moving quite quickly while your ship is at it's apoapse. This increase odds of encounter significantly, you shouldn't have to wait very long. Save all dV for getting re-captured. Once you have an encounter coming up, try to get a pass through atmosphere by planning a maneuver a ways out, 200m/s should be enough to tweak an atmospheric capture.

[Blu_C]

You should have PLENTY of dV to get back so long as your apoapsis high enough that it will encounter Kerbin's SOI, but it is going to take a very long time.

What you can do is create a bunch of manuver nodes. Make sure Kerbin is your target and each new manuver node (after the first) happens after your craft would pass Kerbin's orbit. As you add more nodes for your subsequent passes you should see that you should be able to see how close you get to kerbin on every pass. Keep adding nodes until you see something that looks reasonably close. Then, at that point, make very small adjustments to the first node and watch how it affects the closest encounter.

Because you have such an early manuver node compared to the encounter the deltaV required will be very small. From there, once you are close to your kerbin encounter, you can adjust your orbit to try and get a capture orbit with aerocapture. Just be careful on the heating.

[yorshee]

You might not have enough to be captured by Kerbin. I think you're going to have to send a craft to deliver fuel. I think ideally you're going to want to move through the Kerbin atmosphere or else get gravity assist to slow down from the Mun.

I went with the refueling option as it seemed more fun than sitting around waiting for a close approach to happen.

Rendezvousing in deep space was insanely difficult but I managed to do it!

As it turns out, the craft doesn't have a docking port (I must have been thinking of something else) so I had to use the claw.

The craft now has ~1800m/s of dv! More than enough to get back home.

Thank you everyone!

[Blu_C]

Since things worked out can you please edit your original post to change the question status to Answered?