Constructing rovers in Spacecraft

[CatWithAJetpack]

I can't put a rover into any lander I build, any tips?

[Bej Kerman]

4 hours ago, CatWithAJetpack said:

I can't put a rover into any lander I build, any tips?

What's the problem?

[schlosrat]

Hi @CatWithAJetpack. I think there are basically two ways to do this - relating to the two rover bodies we can build from. Assuming you want a small rover suitable for a single Kerbal to drive around, then here's a solution.

Build your rover around an RC-R "RoveMate". You can either leave it unmanned or add an EAS-1 "Grumble Seat", I opted for the latter. If you've gone with a Grumble Seat, then you may also want a small ladder.

• For wheels go with the smallest as these will help you fit your rover under the lander (RoveMax S2).
• For comms I used a Communotron HG-5 since that folds down to make things compact for stowage - plus it looks cool when deployed.
• You'll want to keep the CG low and add a reaction wheel kit to help you keep it headed in the right direction. I put a TRW-0625 on the bottom node of my RoveMate frame. BTW, when driving, set your SAS to prograde - that seems to help keep you upright and level.
• For power I went with a pair of PB-NUK's and a Z-200 battery. The battery is a good idea, plus has the added bonus of helping with slinging the rover under the lander as you'll see. The PB-NUKs are much more rugged than solar, can be mounted to help keep the CG lower, offer power night or day, and can also be used to help warm up your snacks. Once you strand your Kerbal on the Mun or Minums it's not like their reproductive capacity will ever matter, right? If you consider the max power draw of the wheels and the power output of the PB-NUKs you might think it's underpowered, but it's not. Most of the time you're just cruising along (coasting). Your wheels only really use power to start you moving and stop you, so your main power draw is actually the lights!
• For lights I went with twin  Hi-Intensity Photonic Generators in the front canted slightly outwards (headlights), twin Broad Range Photonic Generators in the back canted more outwards (taillights and good for maneuvering while in reverse). Four Two-Dimensional Photonic Generators (one on each side of the rover, plus front and back), and then three Advanced Photonic Generators on the fuel tank... What fuel tank, you ask? The empty one on top of the battery that works a lot better than a small strut for holding lights and giving the decoupler something to hold on to!
• An empty Oscar-B is on top of the battery as a light weight cylindrical object to (a) mount lights on, and (b) give the decoupler something to hold on to. This seems to work more reliably than a little structural box, though why is probably a matter for KSP2 bug squashers...

Save this little rover in it's own file so you can "merge" it with your lander, or just keep on trucking with building the lander!

• You will need a size M engine mount facing down (the normal direction for these) with an XS decoupler where you might expect to find an engine. Attach your rover to the decoupler and adjust the interstage node of the engine mount so that it's a bit below the rover's wheels.
• Above the engine mount I like to put an MRW-250 with four radial decouplers with LT-2 Wombats attached. Be sure to move the wombats down until the extended legs stop well below the rover. You can test deploying the rover on Kerbin, and if you're able to let it go and drive off with it, then your legs are more than low enough for the reduced gravity of Mun or Minums.
• Above the RW's I put an X200-8 fuel tank with a full load.
• Attach a couple of Mk-55 Thuds to the fuel tank and move them low enough that they're positioned with their skirts ending at about the top of the MRW-250.
• Slap four OX-4L solar panels onto the X200 -8, to complete the descent/return part of the package
• Attach Kelus Long ladder to the X200-8 so your kerbals can climb up and down as needed
• Above the fuel tank attach a size M decoupler
• Build your re-entry capsule with a heat shield (optional presently, but good form to have it), parachutes, and an antenna. Mount this onto the decoupler.
• Litter some lights around where you think they'll help

From here, you need to build or merge and attach a launch vehicle able to put this into a low circular orbit around the Mun or Minmus. I assume that's not a challenge for anyone ready to deploy rovers to the Mun or Minmus!

If you'd like to download the example craft I've put together, you'll find it here.

To use this, there are a couple of "gotchas" with the current EA of the game that you should (and may already) know about. I'll list them here in case anyone else finds this and doesn't already know.

1. Try your best to land in a *very* flat space. This is necessary because of the next issue, which is a KSP2 bug AFAIK.
2. When you decouple your rover it will drop to the surface and may start rolling down hill. This is because a deployed craft starts without any comms connection, and so no ability to control it. To fix this, press "[" to switch to your rover and then  use F5(quick save), and F9 (quick load). That should let your little rover realize it's actually able to communicate and so you can apply breaks, turn on SAS, drive it around, etc.
3. If you goof this a little bit (as I did in my landing on Minmus), then the poor little rover may be in motion rolling (or even tumbling) down hill even after your F5/F9. With SAS turned on, try to get the thing right side up and stable. Keep in mind that with a Rover as your probe core, right side up means your navball pointer (the --v--) will be at or near the horizon with the "v" part pointing into the ground. If you're accustomed to other kinds of probes, this will be different for you - so keep this in mind while you right your rover and get it stopped.
4. When you put your rover into deliberate motion, then be sure SAS is turned on with a Prograde mode. This can help keep it from popping wheelies (or conversely stoppies) due to the high torque of the electric motors.

Here's a shot of the lander on Minmus after the rover was deployed. You can see in this shot the rover and it's pilot (Jeblin) are already on the flats almost 2 km away!

Here's poor Jeblin headed right for a big boulder on his way to the flats. Does he care? No, he does not. He's got the supper power that allows him to drive right through rocks, trees, etc.

Here's Jeblin cruising across the flats at a respectable 6.5 m/s, his bros a good 1.8 km behind him. Go, Jeblin! Go!!!

Edited March 4, 2023 by schlosrat

[schlosrat]

Now, if you'd like to do this with a larger rover things are going to be quite different. You're not going to "deploy" the rover so much as you'll land it, then tip it onto it's belly and drive away! See how here.

[Dr4g0nb4n3]

Here's a lander with a duel-rover set slung below that would be jettisoned during decent landing by parachute and going about their own little missions mapping and rovering all about!