Retrieve Science Lab from Rover

[pokethis]

Hi everyone,

Had KSP for a couple of months and making my first post. Still on stock and planning to be for a bit longer.

I have a mission in mind, to take a manned rover with an MPL to Duna, visit all the biomes collecting data and samples and then return it all to Kerbin, I have so far landed one Kerbal on Duna and returned him so have some experience with bits of this. My Rover consists of just a Mk2 cockpit, the Mk2 to 2.5 adapter, a hitchiker, an MPL and docking port on the back all horizontal plus the experiments and 2 pairs of the XL wheels.

I've just spent all evening trying to work out a way to retrieve the MPL from the rover onto something with a rocket but not have to take the whole rover back to orbit. My initial plan was one or more rockets on wheels that would attach to the MPL via docking ports and then detach it from the rest of the rover but this seems at least very difficult if not impossible on Kerbin so I don't back myself to manage it on Duna.

So does anyone have any ideas? Or has done something similar before?

one thing I just thought of is having another MPL on the ship that goes down and meets the rover at it's final location, collects all the samples and science and returns to orbit, but it feels "cleaner" somehow to be able to return the rover MPL to orbit.

thanks for any advice in advance,

Pokethis

[Lhathron the Elf]

Welcome to the forums!

I am sorry to say I can't help you there. I haven't gone past Minmus yet, simply because I haven't had the time or the patience to plan anything interplanetary. I do know, however, that there are plenty of people here who will help you, and some who have probably done similar things... Good luck!

[tsotha]

Why include the hitchhiker?

I was able to get something similar back into orbit using O-10s and a large monoprop tank. Once in orbit I docked with my refueler, filled it back up with monoprop, and headed home. You don't need much dV if you wait for a transfer window.

The big problem you're going to have, I think, is getting it back onto the surface of Kerbin in one piece. Labs are fragile - you have to be nearly stopped to land them in the water, and on land you need to make sure you have legs or sacrifice parts to absorb the shock. That all has to be designed in from the start.

The first time I tried a mission like that I got so frustrated with the landing I sent up a bunch of capsules to land the science and sent the empty lab to a fiery death.

[Laie]

I've just spent all evening trying to work out a way to retrieve the MPL from the rover onto something with a rocket but not have to take the whole rover back to orbit.

You can, of course, make it so that all the rover bits (wheels&c) are mounted on decouplers and can be jettisoned when done. But that will require a lot more struts to hold it together while you need it; you may also find that the weight on Kerbin increases by a lot. I suspect that picking up the whole rover will be cheaper and easier than making the wheels detachable.

Lifting it can be done with a skycrane; if you don't know what that is, start a sandbox game and check the stock vessels, there is one (small) example. However, docking a skycrane with a lab-rover will be difficult. A contraption that's large enough will also move considerably when you try to lower it by retracting the legs. Hitting any docking port will be difficult, and you probably need more than one. By the time you've solved that problem, the whole thing has again become quite large, heavy, and unwieldy.

Just storing the result in a pod and leaving all equipment behind will be by far the easiest thing to do. There's a reason why NASA did it like that.

The next best solution? Put engines on your rover, make it a rover-lander and let it take off under it's own power. Or make a lab-lander and only put the experiments on the rover.

[gazzareth]

I have landed quite a few Outposts on wheels, which have vertical thrusters so they can descend and move around. Never wanted to take them off again, although my first thought would be to make it in two parts, Rover (and lab etc) attached to a landing / takeoff stage via large docking port, try and make the whole thing VTOL capable on Duna. Then you land, disconnect, do your science and then return and reconnect to the lift stage to leave. Should be possible, you can always test the thing on the Mun first !

G

[Axelord FTW]

I never thought MPLs were worth much. I'd rather put a command module and two hitchicker or any low mass command pod for duplicate experiments/reports. If you are planning on getting all that science back in person anyway, the only advantage of the MPL is to be able to hold duplicates which, like I said, isn't that great for me.

I'd split the to-duna package into two.

One would be a return module with enough d/v and TWR and all that stuff to get your kerbals back to Kerbin.

The second would be your rover proper.

In either case, you'll need to either have a MPL or use three command modules to store all the duplicates.

Edited February 17, 2015 by Axelord FTW

[GoatRider]

Another thing you could do is have a separate science lab on the return vessel, and then transfer the experiments with an EVA Kerbal. What you do with the kerbal is click on the full lab, and press the "take experiments" or "Take data" or something. Then go over to the return lab, and get in.

[pokethis]

Thanks for all the advice!

Sounds like building the rover to return to orbit around Duna as a whole is going to be easiest, hopefully I can design it so I can then detach the other bits from it before the trip back to Kerbin.

Would wings reduce the delta-v needed or just complicate things?

main reason for the MPL is to hold surface samples from each biome without needing a lot of command pods. the hitchiker to be honest was unnecessary role playing so will ditch that when adding fuel and engines.

might have to wait to the weekend to execute all this but will let you know how it plays out.

[Laie]

Wings will probably be more of a burden. Nearly useless on Duna, but complicating the launch and deadweight in transit.

I won't post pics here, under the assumption that you want to try this yourself. But if you need ideas or a template, search this forum for "Biome Hopper Challenge" -- there's at least two lab-rover-landers.

[Sirrobert]

You could have the MPL in orbit, and a tiny lander land on each biome, and than dock with the station each time. Should be cheaper than trying to lift/land the MPL itself, and it'll be much faster than trying to drive all around Duna

[Renegrade]

main reason for the MPL is to hold surface samples from each biome without needing a lot of command pods. the hitchiker to be honest was unnecessary role playing so will ditch that when adding fuel and engines.

FYI, any command pod can hold multiple surface samples - they just have to be from different biomes. (ie, you could have one from highlands and one from midlands, but not two from midlands)