Looking for advice on how to rescue my stranded sun orbiting Kerbals (... to be continued...)

[Seaview123]

Hello KSP Community,

I've been playing a career game and took a contract to go to Moho and get some science. Unfortunately, at periapsis I didn't get a Mojo encounter and missed the rendezvous (It looked okay before I time warped...) So now I've got a boat load of Kerbals in an elliptical orbit between Kerban and Mojo, with less than 300m/s delta-v left and no hope of getting home on their own. (I'd had hoped to collect some Karbonite from Moho/Kerbol orbit and have a space collector attached, but so far no luck.)

I've built a refueling mission with a 2000m/s delta-v rescue vehicle and a full orange tank payload in Kerban orbit for my stranded crew, but I'm not sure how to get it to them. I mean, I missed a Mojo rendezvous, and it's a heck of a lot bigger than my lost-in-space Kerbal's ship. I figure I could use some help.

Does anyone out there have any advice? The lives of my missing Kerbals may depend on it!

Edited February 23, 2015 by Seaview123

[Pecan]

2km/s just isn't going to cut it for a rescue mission near Moho orbit. You need at least 6km/s unless you're being clever with an Eve slingshot or similar. Beyond that, I'd say get the astrophysicists and mathmaticians to plan the mission very carefully ... then put their results into MechJeb for the rendezvous.

[AlexinTokyo]

Claw wrote an excellent tutorial on Kerbolar-orbit intercepts.

It's focussed on asteroids, but the principles will hold for ships.

[Greenfire32]

oof that's a tough one.

My best guess would be to increase your Solar Orbit as much as possible (and as circular as possible, elliptical orbits are hard to rendezvous on) with the stranded Kerbals. Then send a rescue probe (like you've done already) about half way there. Then send another probe to re-fuel the first one. Using the first probe, travel the last half of the way and rescue your kerbals. Then fly back to the second probe to re-top off your tanks and then fly home. You may actually need 2 re-fueling probes depending...

That is probably the most Kerbal way of doing it and it's going to be very time consuming, but if you're anything like me, those Kerbals' live are worth it.

[aleis]

A more kerbal way is to take the craft you used to get that far and just stick it on top of a bigger lifter stage. Instant more dv.

You'd be amazed how much farther one of your crafts can go if you can boost it up to at least 10k before it lights off.

Edited February 20, 2015 by aleis

[Wallygator]

Take the craft you used to put them where that are now. Deleted all the karbonite related stuff. Get rid of any landing equipment. Slap on an advanced probe core. Launch with no crew. Rejoice.

[John FX]

If you wait a year Kerbin will be in the right place to intercept your stricken kerbals.

Edit : If as you say your Ap crosses kerbins path then you may even be able to land with 300m/s...

[NASAHireMe]

The easiest advice I have is to revert to an earlier savefile if you can. Otherwise, you're in for a boatload of trouble and effort.

It's tough to rendezvous with an elliptical orbit. Best bet is to wait a Kerbin year until the major axis is back in line again. Or else use lots of Eve assists.

2K delta-V isn't going to cut it, obviously. Either strip and relaunch your previous vehicle (as the above posters have mentioned), or build a refueling craft so you can complete your original mission (my suggestion; no one likes to abandon a mission). Using several launches, you can build an enormous refueling craft in LKO with tons of fuel and either 3-4 nukes or a Mainsail (my preference; I hate long burns) and use it to rendezvous and refuel your original mission ship. I once shipped 25,000 units of fuel out to Jool in one gigantic ship.

For some tips on getting to Moho, here's a good guide, using multiple Eve and 8 Moho assists. It's basically god-status, but you can still glean some tips. http://forum.kerbalspaceprogram.com/threads/74375-Lowest-Delta-v-to-Moho

[Seaview123]

Thanks for all the help, folks. I'm gonna log this one as "answered" and wait 'till I'm farther along in the tech tree to build a ship with enough delta-V to get my Kerbals (they can hypersleep or something, can't they?). When I build my rescue mission, I'll let you know how I did.

Thanks again, and if anyone has any more ideas, I'd sure like to hear it.