Recovering a lost Kerbal from orbit

[spacedoctor42]

Here's the situation:

Jebediah Kerman is currently out of fuel in orbit around Kerbin at around 200km as the result of a semi-successful mission to the mun. The only part I have currently unlocked that can carry passangers is the Mobile Processing Lab.

Being new to KSP, I am having difficulty building a rocket that can match Jebediah's orbit and have enough fuel to return to Kerbin.

Can anybody point me in the right direction?

Edited March 14, 2015 by spacedoctor42

[GoSlash27]

Well...

You have the command pod mk.1. You should also have the stayputnik unlocked if you have the mobile processing lab.

You should be able to construct a remote guided recovery vessel with an empty mk.1 pod. Alternatively, you could construct a ship with 2 mk.1 pods (1 unmanned), but if it were me I'd go with the stayputnik. No sense in risking another kerbal needlessly.

Best,

-Slashy

[AlexinTokyo]

Don't use the MPL for this.

If you have unlocked probe cores (Stayputnik or OKTO), then use one of those attached to an empty Mk. 1 Command Pod. If not, either wait until you do, or build a two-podded ship. This will be your 'rescue pod'. Don't forget the parachutes, and if you're using a probe, don't forget solar panels.

Note that if you use the Stayputnik, you won't have access to SAS, so flying it can get a bit hairy.

Your rescue pod will need about 500 m/s of ÃŽâ€v for orbital maneuvering (75 km circular parking orbit to 200 km circular orbit for rendezvous, to 40 km Kerbin-return). It's actually a bit less than this, so this includes some safety margin.

First you'll need to launch the rescue pod into a 75 km (this doesn't have to be exact) orbit. Since you can get to the Mun, I'm going to assume this isn't a big deal for you.

Set Jeb as your target by clicking him in the map view, and select 'Set as Target'.

Then, you'll want to create a maneuver node and pull on the prograde handle until your projected apoapsis matches Jeb's 200 km orbit. Don't perform the maneuver yet.

Now, take that maneuver node and play with the timing (slide it around your orbit and use the +/- orbit buttons) until you get 'closest approach' markers (little red or orange arrows) close together in the same spot your projected orbit meets Jeb's. This step can take a bit of time, and can be a little frustrating, especially if you're not used to it. The PreciseNode mod (if you're not averse to mods) can make it quite a bit easier, as it gives you a finer control, and avoids the niggly mouse-movement-related issues.

Once you see the closest approach markers, mouse over them and you will see how close you will pass to Jeb, and where your relative positions will be.

Ideally, you would want to have the closest approach within about 5 km, and you would want Jeb to be behind you in the orbit. Don't worry too much about this, though.

When you're happy with the projected approach, warp to the maneuver and perform the burn. Then coast up to 200 km and your rendezvous point.

Once you get close to Jeb, your navball will switch into 'Target' mode. In this mode, the speed reading shows your speed relative to the target. The pro- and retro-grade markers on the navball also switch to showing the vectors relative to the target.

When you get to the point of closest approach, burn retrograde (relative to the target) until your relative velocity as displayed on the navball goes to 0. At this point you're basically flying in formation with Jeb. If you're close enough (within about 1 km) you should be able to switch control to Jeb, EVA him over to the rescue pod, and jump in. If you're not familiar with EVA control, you might want to practice first (I think there's a training scenario that will allow you to do exactly this).

If you're still too far away, then burn directly towards the target (the pink circle on the navball) until you get a closing speed of a few m/s. After closing with the target, once again burn retrograde to zero out the relative velocity. You can repeat this process until you're as close as you want to be.

Once you get Jeb on board, burn retrograde to deorbit and return to Kerbin. (You did remember the parachutes, right?)

Don't be surprised if this doesn't go smoothly the first time; orbital rendezvous is one of the more difficult skills in the game. Be prepared to use F5/F9 (or, better, Alt-F5/Alt-F9) to practise until you get the hang of it.

[Phil deCube]

You could try getting out and pushing. Dump any remaining stages, so that you only have the capsule left, point the capsule toward the retrograde marker on the Navball, EVA Jeb, position him at the bottom of the capsule in the centre, and push with the W key. Do this for a while (don't run out of fuel), get back in and check the situation (and refill the EVA fuel tank). If necessary get out and repeat. Get the periapsis below 30km and you should be able to renter and land. Good luck!

[mattinoz]

I haven't tried this but I might for fun unless someone response that it doesn't work.

Could you send up one craft without space to transfer and well just bump gently into the stranded craft like docking but without dock clamps, then fire the engines to push the periapsis of both below 40km?

Both pilots go home in their own craft.

[Kryxal]

Craft don't generally bump so well without a framework to keep the bump target from sliding off to the side.

[eddiew]

...First...

These are good instructions, won't waste my time trying to better them

It's a little late now, but a good tip for the future is to never burn fuel circularising around Kerbin when returning from Mun. Set your Munar escape burn to put you at a 40-45km periapsis and the atmosphere will aerobrake you down to a much tighter AP. If you have spare fuel you can then choose to lift the PE to ~75km and wait for a good time to drop onto KSC. If not, just loop round again and the atmosphere will capture you and you'll land 'somewhere' - but you're guaranteed to land

Also, remember that kerbals in stock can photosynthesise; Jeb won't starve or suffocate, ever. If you don't feel you have the tech to get Jeb back, just hire another pilot (free) and let him run the next few missions until you unlock something that will help (maybe the inline pod, or a probe core with SAS).