I suck at this!!!!

[Perotis]

I got a bunch of science stranded orbiting Jool because I didn't have enought D/v.  So I try and sent a rescue mission.  A dozen tries later I end up with the science in the rescue ship with 3500 D/v to get home.  I think I'm in good shape.  I get an encounter with Kerbin with 2400 D/v left.  But, when I try and get into orbit, the maneuver says it will cost 3500 D\v    >:(   

I hate the idea, but I'm gunna have to turn on infinite fuel to get this ordeal over with.

[KSK]

You could try a bit of careful aerobraking at Kerbin. That should lower the delta-V requirement by quite a bit if your ship can take it.

[GeneralVeers]

No cheats necessary.

It's hero time for your pilot! Send him out on EVA, fly him around to the side of the ship facing prograde, plant him right up against the hull, and thrust forward with the EVA jetpack. If needed, have the pilot board the ship, refill his EVA fuel tank, and repeat as necessary.

My first-ever Minmus landing ran into a very minor fuel problem, and I was able to save the mission this way! Good luck, and if anybody at Mission Control asks where the hell your pilot is getting the extra fuel from, have him fired.

[worir4]

Like @GeneralVeers said, get out and push! It is one of the classic and totally professional maneuvers in KSP!  Warning: May result in death of kerbal and/or loss of vessel.

[regex]

Happens all the time.  I went to Jupiter the other night with the intention of landing on Callisto and despite two very low Callisto intercepts, and the use of all my hydrazine (was on RCS because the S5.92 was out of hypergolics), I only managed an elliptical Jupiter orbit somewhat near Callisto orbit.

Last night I tried an aerocapture/landing at Mars and pancaked the probe because the chute never opened and the descent engines weren't properly ullaged in time.

It happens.  Everyone sucks at this game.

[tater]

Your experience is not remotely unique, and it's not helped by Squad's refusal to give players the data they need to plan missions (though there are mods that help, KER, for example).

One suggestion is to send probes. If your first lacks the dv to get the job done, send more propellant next time.

In your particular case, can you use the kerbin encounter (perhaps combined with a Mun pass) to put you into a solar orbit that will allow another encounter later?

[GeneralVeers]

25 minutes ago, regex said:

Everyone sucks at this game.

Pssh. Not me. I checked my own savegame file and I have the badass flag!

[Loren Pechtel]

7 hours ago, Perotis said:

I got a bunch of science stranded orbiting Jool because I didn't have enought D/v.  So I try and sent a rescue mission.  A dozen tries later I end up with the science in the rescue ship with 3500 D/v to get home.  I think I'm in good shape.  I get an encounter with Kerbin with 2400 D/v left.  But, when I try and get into orbit, the maneuver says it will cost 3500 D\v    >:(   

I hate the idea, but I'm gunna have to turn on infinite fuel to get this ordeal over with.

I don't see the problem here.  While I have yet to leave the Kerbin system you come back from the moons with something like 900 m/s too fast for orbit.  Set your periapsis to the right altitude, hit the atmosphere at 3000 m/s and everything's fine.

Since you have 2400 m/s of fuel left simply burn almost all of it to slow you down.  (Reserve a bit to adjust your entry point.)  You'll hit atmosphere at about 1200 m/s above orbital velocity.  Since I have never burned more than half my heat shield at 900 m/s above orbit this should work.

(You are bringing them home in something that can re-enter, aren't you?)

[Snark]

As KSK points out, aerobraking can be your friend. If you have 2400 m/s of dV, and the game is telling you that you need 3400 m/s to make orbit, that's great! It means that after burning all your fuel just before hitting atmosphere, you're only going a thousand m/s faster than orbital velocity. Easily survivable, as long as you have a heatshield.

If, on the other hand, you don't have a heatshield, you can still pull it out of the hole. Just make a rescue ship for your rescue ship. Something small and light, with enough space for the crew, and enough dV to make LKO with 2-3 km/s left over. When your returning ship gets to Kerbin periapsis, it uses all its fuel to slow down. Then your new rescue ship can rendezvous, pick up the crew, and head home.

Edited March 14, 2016 by Snark

[Mr. Speed]

Snark is right, you could rendezvous as it is coming into Kerbins SOI. Just like a simple asteroid intercept.

[Nich]

Yes a lot like an asteroid intercept through the kerbin system.  Although question is 3400 highly elliptical capture or 100x100 capture? If it is highly elliptical capture that means even after burning off 2400 he will still be going roughly 4300 m/s which is still pretty darn explody.  Would a Gravity brake off eve with a correction burn to Kerbin be a possibility or are you simply going too fast for eve to do anything useful?

Edited March 14, 2016 by Nich

[RocketBlam]

My last mission to Jool was the same way, so don't feel bad, even though I've been there several times in previous games. I sent a Laythe lander with a transfer stage that I thought could bring it back (since it would be a lot lighter after returning from the surface of Laythe) but I badly misjudged the fuel I would need. And I mean badly.

I ended up sending an ISRU unit to Vall, and having to a) send fuel to the Laythe lander/transfer stage in Laythe orbit, since it couldn't even get out of orbit with the fuel it had, then doing another round to fuel it up for the return to Kerbin, and even then I didn't have enough. 

Man, it's kind of embarrassing.