Transporting a rover to the mun

[Actually_New_KSP_Player]

Complete vanilla 1.4.2 career mode.

I looked up for some video tutorials on YouTube, but these ones were pretty small and light while mine looks like this and weighs about 700 killos 

 

Two seats for the pilot and scientist, the experiment storage unit are for testing purposes since i wasn't sure how the kerbals will store the data without it (my mission is to collect the data from all mun biomes) and i was about to test it, but a lot of problems appeared.

After about 2 hours of testing different builds i realised that it's pretty hard in terms of stability to transport that thing, also had troubles with fuel on landing + wasn't sure how exactly i'm supposed to land it - should i build it underneath the fuel tanks and place the rockets on sides making my rocket VERY unstable or should i build it on side making it even harder to land since i need to drop it?

Am i missing something in building or maybe science? Just in case you wonder (230 science left).

Edited September 4, 2018 by Actually_New_KSP_Player

[mystifeid]

It is far from being the most elegant solution but it is very easy to place rovers atop slow boosters that have a lot of asparagus stages and a lot of dV. In the screenshot below the rover weighs nearly 14 tons and the booster is about to take it into orbit, transfer to Eve, establish a 150km orbit and then do a powered descent into the atmosphere - with 3 Kerbals sitting exposed in command seats - to a height of about 70km and a speed of about 600m/s.

When the rover is exposed you don't want it tearing up through the atmosphere quickly - at full throttle this one accelerates up through Kerbin's atmosphere quite slowly - at 12km it is only moving at 300m/s (start of turn) - yet it is extremely stable and very easy to launch. (It helps that the booster is massively heavy compared to the rover - total weight on the launchpad is 4000 tons).

For landing on airless worlds it has a very small last stage which it uses to touch down, then it falls over slowly with SAS and RCS working. This works even on Tylo.

I'd call this the brute force approach - and that booster is capable of reaching and landing that rover anywhere in the Kerbol system.

Edited September 4, 2018 by mystifeid

[bewing]

I think mystifeid's solution is basically the right one. Sit the rover on top of your rocket in whatever orientation you like best. Don't use a fairing because it would be too big. Launch it straight up, fairly slowly -- with a lot of aerodynamic attitude control on your rocket, plus a decent amount of gimbal. The aero control surfaces will keep the rocket flying properly up to maybe 12km. The rocket will probably continue to try to flip up to about 30km, and that's what you need the gimbal for -- to keep the rocket flying straight between 12 and 30km. Now, I am in the camp of people who like to launch directly to my target without going into orbit first. I assume your target is the Mun. So I say, lead it by about 60 degrees and just go straight up until you get to the Mun. Landing is definitely trickier with a big fat rover on the front end. Usually you can wait to decouple it until you are landed. It will tumble down to the surface, but that usually won't damage anything. Trying to drop it from an altitude is much trickier.

[Actually_New_KSP_Player]

1 hour ago, mystifeid said:

Looks like a decent solution.

 

23 minutes ago, bewing said:

 Landing is definitely trickier with a big fat rover on the front end. Usually you can wait to decouple it until you are landed. It will tumble down to the surface, but that usually won't damage anything. Trying to drop it from an altitude is much trickier.

Actually the main problem with Mun and dropping the rover on it is that it's bounces off the surface and flips over, right now i landed it successfully but it's still really hard to move due to very low gravity.

[mystifeid]

1 hour ago, Actually_New_KSP_Player said:

Actually the main problem with Mun and dropping the rover on it is that it's bounces off the surface and flips over, right now i landed it successfully but it's still really hard to move due to very low gravity.

1. Do you have a reaction wheel for a decent amount of SAS stability assist?

2. Do you have monoprop and an RCS system?

3. Are you using alternate key bindings for movement instead of wsad (which also affect roll/pitch/yaw)?

4. Have you tried modifying the spring/damper settings of the wheels in the VAB (cannot be done once on the Mun)?

5. Have you tried adjusting friction settings on the wheels (can be done anywhere)?

6. Have you tried adding more wheels?

7. Have you tried increasing the size of the rover while lowering the center of mass?

8. Is the controlling part aligned correctly (when on the surface, navball should be blue on the top half and brown on the bottom)?

9. Are you using any trim setting on your rocket? If so, make sure all trim is cancelled with Alt+X (on PC) before the rover touches down.

For testing purposes you can use the Hack Gravity cheat in the Alt-F12 console and try different things at KSC with the Mun's gravity but since this might affect other things it might be best to do this in a separate sandbox.

Also as a recovering Mechjeb addict I can tell you that the stability control in MJ's rover module is pretty good.

Having said all that, the Mun is still not the easiest place to drive a rover but if you can do it there, you can do it anywhere.

Edited September 5, 2018 by mystifeid

[Actually_New_KSP_Player]

53 minutes ago, mystifeid said:

1. Do you have a reaction wheel for a decent amount of SAS stability assist?

2. Do you have monoprop and an RCS system?

3. Are you using alternate key bindings for movement instead of wsad (which also affect roll/pitch/yaw)?

4. Have you tried modifying the spring/damper settings of the wheels in the VAB (cannot be done once on the Mun)?

5. Have you tried adjusting friction settings on the wheels (can be done anywhere)?

6. Have you tried adding more wheels?

7. Have you tried increasing the size of the rover while lowering the center of mass?

8. Is the controlling part aligned correctly (when on the surface, navball should be blue on the top half and brown on the bottom)?

For testing purposes you can use the Hack Gravity cheat in the Alt-F12 console and try different things at KSC with the Mun's gravity but since this might affect other things it might be best to do this in a separate sandbox.

Also as a recovering Mechjeb addict I can tell you that the stability control in MJ's rover module is pretty good.

Having said all that, the Mun is still not the easiest place to drive a rover but if you can do it there, you can do it anywhere.

1. Didn't even thought about building it on rover though, so no.

2. No

3. No because i didn't know that.

4. Have no idea what they do so no again.

5. Yes and i noticed that it's more stable at maximum of 5.

6 and 7. Currently building new rover and gonna add more wheels, but how can i lower the center of mass? I mean it's centralized, but how can it go lower the level of my rover?

[mystifeid]

18 minutes ago, Actually_New_KSP_Player said:

but how can i lower the center of mass?

Raise the height of the wheel attachment point for a start. In the picture above you have the wheels attached low down on octagonal struts which are themselves attached to the undersides of other octagonal struts. Plenty of room for improvement there.

18 minutes ago, Actually_New_KSP_Player said:

Yes and i noticed that it's more stable at maximum of 5.

I remember when I used to do that. Usually means everything else needs improvement. With a big area and low center of mass it's good if the rover can slide a little which often stops it from rolling.

Don't expect to come up with some fantastically successful design quickly (well, you might) - just be prepared to modify/change it as you gain experience. And learning to drive them is an art in itself.

Edited September 5, 2018 by mystifeid

[mystifeid]

39 minutes ago, Actually_New_KSP_Player said:

3. No because i didn't know that.

Essential. I have my numberpad 2,4,6,8 keys set as alternates for movement. Even though I still often use "a" and "d" for left/right, I always use "8" and "2" for forward/reverse. Also I have numpad "5" set as an alternate brake key which allows me to generally find it without looking.

Edited September 5, 2018 by mystifeid

[Actually_New_KSP_Player]

31 minutes ago, mystifeid said:

I remember when I used to do that. Usually means everything else needs improvement.

But what exactly does these spring/damper do? I've tried maxing them out and traveling on kerbin in test race and didn't noticed the difference at all.

 

Also that's what i've come up with, should i remove the landing legs or not? Because some tutorials say that they are not very useful for heavy crafts and better use the RCS instead.

Same for wheels angle, does it actually help?

[mystifeid]

14 minutes ago, Actually_New_KSP_Player said:

But what exactly does these spring/damper do?

@bewingcan probably give you the official version here. Generally I try to set them as high as I can without the rover starting to jump around when it's parked. This "seems" to improve the height I can land jumps from (springs) and certainly appears to reduce the bounce when I hit (dampers).

19 minutes ago, Actually_New_KSP_Player said:

should i remove the landing legs or not? Because some tutorials say that they are not very useful for heavy crafts and better use the RCS instead.

I prefer to flick on the RCS in an emergency. Learning to recover proficiently takes practice though.

20 minutes ago, Actually_New_KSP_Player said:

Same for wheels angle, does it actually help?

Never tried it. Looks like I never will.

21 minutes ago, Actually_New_KSP_Player said:

Also that's what i've come up with

This design will have a lot of problems when running along the top of ridges - ie it will bottom out a lot.

[Actually_New_KSP_Player]

12 minutes ago, mystifeid said:

This design will have a lot of problems when running along the top of ridges - ie it will bottom out a lot.

Think that should do then.

 

4 hours ago, mystifeid said:

establish a 150km orbit and then do a powered descent into the atmosphere - with 3 Kerbals sitting exposed in command seats

Talking about the rocket how do you place kerbals on the rover before launch? I don't see any other command pod on that screenshot.

[Tonka Crash]

The Mk2 Expansion mod has a cockpit I like for manned rovers and the Mk2 cross section makes for wide low cg rovers. I've also found larger rovers like this a bit more stable than lightweight minimalist rovers in low gravity. This one used the Mk2 Expansion science lab for the main body. Once landed there are sepratrons arranged asymmetrically on the skycrane staged with a decoupler to spin it off and crash it nearby.

[mystifeid]

20 minutes ago, Actually_New_KSP_Player said:

Talking about the rocket how do you place kerbals on the rover before launch? I don't see any other command pod on that screenshot.

There are two Mk2 lander cans below the rover. Kerbals are launched in the lander cans then eva'ed into their command seats prior to landing.

[Actually_New_KSP_Player]

For some reason i can't connect my rover with any detail of the ship, either it's some structure, decoupler, side attachment or even docking port it either won't connect or goes right through my rover making it stuck in textures.

[bewing]

7 minutes ago, Actually_New_KSP_Player said:

For some reason i can't connect my rover with any detail of the ship, either it's some structure, decoupler, side attachment or even docking port it either won't connect or goes right through my rover making it stuck in textures.

The part of the rover that you are trying to connect to the ship needs to be the root part. Use the reroot tool, click on the rover, then click on the part that you want to use for the connector.

[TanDeeJay]

I've made my rover with a detachable/re-attachable lifting body so it can get back into orbit to refuel/go to another biome without having to drive all the way

 

 

The rover is attached to the lower stages with a stack separator.  I spent a while adjusting the height of the legs with repeated launches so that the pair of docking ports above the Science Module Jr just clear when the rover is uncoupled and the landing legs retracted.  Landing legs are extended for landing.  Now I can drive around collecting science, and then return by docking the rover to the lifter.

Only problem I found with this design so far is that there is a solar panel below the upper ladder that creates problems when the kerbals are trying to re-enter the comand module.  I have 6 seats on the rover so there is spare space to pick up any stray kerbals I find that I left behind earlier... 

[Sharpy]

That's not heading in a good direction...

1. With a good reaction wheel (and a plenty of electricity to keep it running) you don't need RCS. RCS is useful when going up really steep slopes, or especially if you jumped off a ledge too high, to brake your descent. It's not essential though; you shouldn't use it for roll at all (switch actuation toggles for yaw pitch roll off), and then you won't need much monoprop. (with RCS rotation control, no amount of monoprop will suffice).

2. Sooo big, flat, it will be hard to keep stable. On Mun, when driving, you spend 80% of time "airborne", and use the reaction wheel more than steering. You absolutely don't need that many times the science experiments if you have a scientist and the box.

My suggestion: make it way more narrow, look into the "aerodynamics" tab for some wing parts that make much better frame elements than the heavy girders (if you flip and crash, you won't benefit much from the frame surviving if the rest goes bang.) Make steering/acceleration different than yaw/pitch/roll controls (WSADQE), e.g. arrow keys, and when driving, SAS to prograde (Surface mode, not Orbit!), right hand on arrows, left hand on Q/E to fix roll to stay wheels down (SAS will take care of pitch/yaw), turn by gently tapping simultaneously left+a, right+d.

And really, really if you can scrunch that bit of science, get the ruggedized wheels. Unless you plan to take a three-star engineer to fix this crap. You won't visit all the biomes with these.

 

BTW, all the clever "skycranes" that try to land your rover wheels down, engines overhanging to the sides, undock, then fly away towards the setting Kerbin? Overkill like heck. Good reaction wheel, one decoupler stuck right to the "butt" of your rover, one size 1 medium fuel tank and a Terrier engine. And maybe a fairing. That's all you need for your "skycrane". Set down on the Terrier gently (or not so gently; if it blows up, no biggie), then use the reaction wheel to tip over onto your wheels, then decouple the tank and the engine. And if you didn't tip onto the wheels, just roll onto them using the reaction wheel. You SHOULD have enough torque to do that. If you don't then your rover wouldn't survive long anyway.

[Actually_New_KSP_Player]

20 minutes ago, Sharpy said:

Sooo big, flat, it will be hard to keep stable.

Actually no, it's quite stable, but pretty slow.

 

25 minutes ago, Sharpy said:

You absolutely don't need that many times the science experiments if you have a scientist and the box

Do scientist repair the goo too? Never had to test it out since i discovered Science Jr. reparation like 5 minutes ago and wiki doesn't even say about it. Also i already understood that due to my rover's low speed it will take hours to cross over all biomes and collect each of them in goo.

 

 

[Sharpy]

Yep, heavy.

What I meant about the delivery. This is a very minimalist rover, but the same technique works fine for larger ones just fine. (this one is capable of landing on Mun from LKO, plenty enough fuel for that.) You really don't need any more complex "skycrane".

 

[Actually_New_KSP_Player]

Off-topic question but still, why can't i see Minmus AN\DN nodes while orbiting the Mun? When i select it as a target on Kerbin orbit i can easily line up our orbits to 0 angle difference, but on Mun they just doesn't appear, even if i make it up to low kerbin orbit which is 70 kms.

[Kryxal]

Have you tried shifting your focus to Kerbin?

[Actually_New_KSP_Player]

18 minutes ago, Kryxal said:

Have you tried shifting your focus to Kerbin?

Still no effect.

[Man in the Mun]

To transport rovers, I place a docking port on top of the rover. Then for the ship / rocket.... I build a central fuel tank with a docking port on its bottom, I then hang the rover from this fuel tank. Then using girders I build four arms that stick out the side of this central fuel tank and place a stack of engines and any additional fuel tanks on the ends of each arm.

So basically I end up with a square shaped ship with the engines in each corner and the rover hanging in the middle. Land the ship then decouple the rover.

For extra oomph, I add an extra rocket stage underneath each corner and going all asparagus got the rover to Minmus with fuel to spare.

 

Album will appear when post is submitted

Edited September 7, 2018 by Man in the Mun

[chico]

I always attach my rovers vertically using a Clamp-O-Tron Port Jr so I can attach it to any existing ship. Before dropping it I turn on the rover reaction wheels to control the fall from ship, but in low gravity bodies like moon it don't even matter, the rover can land upside down and rotate up after.

I cant imagine using rovers with no engines, I would die of boredom. This rover can travel at 100+ m/s.

[TanDeeJay]

Does it need the 6 wheels? My current rover is using 4 of those wheels without too much problems. Taking out the middle pair of wheels would lower the weight and part count, but how would that affect handling? 100m/s wow thats fast! I usually hit the brakes when I get over about 30. Had way to many flips