Recovering an orbiting vessel

[LynixF]

I have a rocket that I sent to the moon in a crazy elliptical orbit around Kerban, it has fuel and all, but there is sadly no battery left. The vessel has around 300 science packed on it, and I have no idea how to send a ship to return it. I can get to the vessel rather easily, but once I get it how do I 'attach' the two ships and de-orbit the lander?

[Kasuha]

If it has fuel and there is Kerbal inside it, you can deorbit it even without electricity. Let it coast to apoapsis, then set minimum throttle (right above zero) and turn the ship retrograde - engine gimbal still works so it will turn. Once it is turned retrograde, use full throttle and burn until the periapsis is in atmosphere. And then just land.

[Taki117]

If it's a probe and it has retracted solar panels (Why you would ever want to retract them is beyond me) you can send up a Kerbal to manually extend the panels.

As far as "Attaching" two rockets together you need a docking port on each ship.

[LethalDose]

What Kashua said, but you probably want to aim for a periapsis around 25 - 35 km above Kerbin's surface, even though atmosphere starts at 70 kms. The lower atmosphere will slow you down faster. If your periapsis is above 40 km, it will likely take several passes for your to deorbit.

[xcorps]

If it's a probe and it has retracted solar panels (Why you would ever want to retract them is beyond me) you can send up a Kerbal to manually extend the panels.

As far as "Attaching" two rockets together you need a docking port on each ship.

You can use the claw with a solar panel attached to it, put a decoupler to separate the claw from the rescue rocket. Attach it to the top of your dead rocket or you will roll like mad.

[araveugnitsuga]

If it's a probe and it has retracted solar panels (Why you would ever want to retract them is beyond me) you can send up a Kerbal to manually extend the panels.

As far as "Attaching" two rockets together you need a docking port on each ship.

Or the claw and a relatively flat attachment point.

Alternatively rendezvous with it, have the kerbal extract the science, and return home leaving the probe floating on space.

Or in the insane case you could push it with another ship or a kerbal but you'd still have no control over it, it'd just be on collision course.

[LethalDose]

If it's a probe and it has retracted solar panels (Why you would ever want to retract them is beyond me) you can send up a Kerbal to manually extend the panels.

As far as "Attaching" two rockets together you need a docking port on each ship.

Or a claw on just one ship.

Or you can send another ship up with a kerbal to rendezvous with the "dead" ship and either a) send the kerbal to collect the science from the dead vessel and come back, if the dead ship is unmanned OR put an extra seat in the ship you send up, have the kerbal on the "dead" ship collect the science from the instruments, and come back in the new ship.

[cantab]

As LethalDose says, when you're controlling a Kerbal on EVA, if you're close to a command module or an experiment you can right-click it and take the data out. Then do the same to put it in a new pod (or board said new pod).

But if it's a Kerballed mission, then if your engine gimbals as suggested you can use that for control. If your engine doesn't gimbal (the LV-T30, the first engine in career mode, doesn't), turn SAS off, run the engine briefly anyway to get some electricity and start your ship slowly rotating. If your engine doesn't gimbal or generate electricity (ie it's an LV-1 or LV-1R "ant engine"), have your Kerbal get out and set the ship gently rotating, then burn when it's pointing in the right general direction.