Any tips on strapping my rover to my rocket?

[TehUndeadMerc]

So I've been messing around with trying to make rovers to explore the planets at a faster pace than walking kerbals with the added bonus of not worrying about having them get too far or stuck away from their pod. However I'm having a bunch of issues.

Firstly: My rocket keeps wrecking itself during staging (It does stage properly)

Secondly: I have no clue how to attach my rover to the rocket! If I put it under it gets sat upon, if I put it on top it seems to unbalance my rockets.

Here are a few angles on my rover and a picture of it's delivery rocket

Rover

Rover on Rocket

Underside of the Rover

(direct links)

http://i39.tinypic.com/2cz3fao.jpg

http://i40.tinypic.com/2mra9et.jpg

http://i43.tinypic.com/iz6w47.jpg

Edited November 18, 2013 by TehUndeadMerc

[el_coyoto]

Ah, well, hum, good luck...

I build most of my rovers symmetrical on longitudinal axis and stage them horizontally to avoid these sorts of problem.

Or maybe, you could add TWO of them to your lander/stage, attaching them to the side (and come up with a reliable way to decouple them) in 2x symmetry, making the craft symmetrical again ?

[DeMatt]

When I build a rover, I tend to carry it horizontally instead of vertically. I then build my lander "above", wider, and deeper than the rover, so that when the lander touches down, the rover is wheels-down and dangling just above the surface:

  Lander
  /  |  \
 / Rover \
/         \

Maybe try redesigning your rover to be carried that way? If you don't want a full lander, you could also go with a kind of skycrane route, and have a "landing thruster pack" that brings the rover down to a landing on its wheels, then gets detached and flown away. Bear in mind the "wider" part; if your thrusters fire into the rover, they won't generate any actual thrust as their exhaust bounces off the rover.

Turning on the "Center of Mass" and "Center of Thrust" indicators in the VAB (the three green buttons in the lower-left corner) can help to make sure you've got the rocket balanced correctly when you add the rover.

[TehUndeadMerc]

Well that could work I just don't see the use to sending 2 rovers to the same planet.

[CalculusWarrior]

The famous Scott Manley did a video on rover transportation:

I'm not sure if you can manage to modify your rover to take into account his design tips.

[el_coyoto]

Well that could work I just don't see the use to sending 2 rovers to the same planet.

I know, especially if you have to drop them at the same location to keep the craft symetrical...

[TehUndeadMerc]

I watched a bunch of Scott manley's video but I guess I didn't catch up, it was very helpful. thanks!

[DrMonte]

I think adding one SAS module would help to balance the rocket without further modifications. Although you should try moving your rover into the center of mass as much as possible.

[phuzz]

My last rover had a small docking port on top to connect it to the 'skycrane' descent stage.

However, to get all that into orbit I ended up flipping it upside-down, so the rover ended up flying wheels first into orbit. It looked weird, but it worked in the end.

[Deadweasel]

I know, especially if you have to drop them at the same location to keep the craft symetrical...

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[TR]

[TD]

Actually.... symmetry really only comes into play during the course of GETTING there. Once you're in orbit, it ceases to be a concern, really. For example, LRCV-101 Bruin delivered FOUR rovers to Duna orbit. They are deployed as-needed from there, as the ship can orbit stably and indefinitely, even if the payload is imbalanced, and as long as it's not going to be burning the main engines.

Why more than one rover? Because I'm not going to attempt to drive around the entire planet to get a closer look at land features/anomalies. The dropships can deploy them to points of interest from orbit, then either retrieve them or shuttle them back to the ground station they're assigned to.

This is an extreme example, I think, but it makes my point. You only have to worry about load balancing for the outbound journey. Once you're there, develop a means of delivering from orbit, and suddenly you're able to deliver as many probes/rovers as you see fit, instead of one at a time. [/TD]

[/TR]

[/TABLE]

[Andersenman]

A small rover underneath drop tanks, with additional tanks as counterweight:

Javascript is disabled. View full album

[Monkeh]

Well that could work I just don't see the use to sending 2 rovers to the same planet.

What if you have 2 kerbals in your command pod? You don't want them fighting over who gets to go on a ride now do you?

Here's some of my attempts at rover delivery down the KSP years, maybe somewhere in this pile of drivel you may find some inspiration.

Number 1: Stick it on the top

First attempt:

Second attempt:

Number 2: Make your lander become your rover:

Number 3: Stick it on top again...but this time with parachutes!

Number 4: Symmetrical radial attachment

Number 5: In-line and measured to re-dock with lander

It actually failed to re-dock on the Mun due to lower gravity not pulling the lander down far enough. Damn it.

Number 6: Symmetrical radial attachment with parachute

Number 7: Inside a cargo bay and then dropped with a parachute

You can see that one in some detail here in my blog post.

That is, of course, far too many screenshots for one post. I'm such an idiot. Hope somewhere in there you find something that helps, good luck

Edited November 18, 2013 by Monkeh

[TehUndeadMerc]

Well currently I'm only able to get rockets to mun and minmus. I always get lost around the sun when I try going to other planets and can't figure out how to get to the planets. Even mechjeb is horrible as I tend to have low-ish orbits and it makes me wait 365 years or so

[Deadweasel]

Well currently I'm only able to get rockets to mun and minmus. I always get lost around the sun when I try going to other planets and can't figure out how to get to the planets. Even mechjeb is horrible as I tend to have low-ish orbits and it makes me wait 365 years or so

Two things are most important when getting to the other planets:

1. The angle of the target planet in its orbit from Kerbin (Duna for example needs to be around +45 degrees ahead of Kerbin at the start)
   
2. The angle from which you begin your transfer burn in Kerbin orbit (again to Duna, start from about 100km altitude at 90 degrees prograde, and just past the night side terminator)
   

I use Protractor and PreciseNode mods to determine when to launch, when to start transfer burn, and for how long. It's done wonders for my ability to do these transfers, when I never used to leave the Kerbin system all that often previously.

[Monkeh]

I learned to get to the other planets without MechJeb and if I can, by lord above, anyone can.

Get to orbit.

Burn out of Kebin SOI. (important- trying to do interplanetary transfer from Kerbin's SOI sounds like a recipe for disaster)

Once orbiting the sun, click on target planet and set as target.

Play with maneuver nodes, (normally around the ascending or descending nodes), until you see the little grey markers on your projected orbit path and then get them to intercept by either moving the position of the node or changing the amount of delta v you're adding.

Welcome your interception node.

Hold a right click on the periapsis of the body your looking at and it will stay on the screen when you move your mouse away.

Fine tune the delta v whilst watching the periapsis marker and stop when it's where you want it.

Start the burn half way in front of your node with respect to your estimated burn time, so a burn time of 5 minutes should be started at t-2:30 assuming you can full throttle it and your craft doesn't lose weight as it burns...

Coast up to your destination and then burn retrograde at periapsis blah...blah...blah if you got to the Mun and Minmus the you know this bit.

Profit.

Good luck, you got dis!

Edit: The post above mine is the sensible and efficient way of doing things, mine has worked fine for me but requires some over engineering of fuel and delta v.

Edited November 18, 2013 by Monkeh

[Soda Popinski]

I slapped my rover on top of my lander bound for Duna. I set it up so it would be ejected via separatrons and simultaenous undocking (set up an action to do both), and pop a chute on the rover, since Duna has an atmosphere. Unfortunately, one wheel broke (I was using the crappy first set of wheels), so it wouldn't drive very well.

I know what you mean about getting to other planets. I just landed my first survivors onto Duna. I don't use MechJeb, and it seems to only give single optimal periods. Instead I used KSP Launch Window Planner, on the web to let me know when your closest launch window is. With that, you just set your manouver node at sunset to go to an outer planet, or sunrise to go to an inner planet, fiddle with the delta-V on the maneouver node until you get capture.

Edit: I just watched the Scott Manely video. Wish I knew I could repair the tire. D'oh!

Edited November 18, 2013 by Soda Popinski

[DrMonte]

It actually failed to re-dock on the Mun due to lower gravity not pulling the lander down far enough. Damn it.

I was thinking about such design - You should have tried pulling up the legs of the lander for the moment making it sit on the rover.

Separating vehicles in the air is dangerous. Don't get apart more than 2km (2.25 to be more precise).

Actually I didn't have much trouble landing with ~1t rover on a side without counter-mass (don't have pictures now) but that's not a good design. For the next mission I found the way to put it under the lander (my solution was "Rockomax 48-7S" engines). What I wanted to say is that center of mass is not so much trouble as you might think if you use correct tools to resist it.

[Deadweasel]

I learned to get to the other planets without MechJeb and if I can, by lord above, anyone can.

Get to orbit.

Burn out of Kebin SOI. (important- trying to do interplanetary transfer from Kerbin's SOI sounds like a recipe for disaster)

Once orbiting the sun, click on target planet and set as target.

Play with maneuver nodes, (normally around the ascending or descending nodes), until you see the little grey markers on your projected orbit path and then get them to intercept by either moving the position of the node or changing the amount of delta v you're adding.

Welcome your interception node.

Hold a right click on the periapsis of the body your looking at and it will stay on the screen when you move your mouse away.

Fine tune the delta v whilst watching the periapsis marker and stop when it's where you want it.

Start the burn half way in front of your node with respect to your estimated burn time, so a burn time of 5 minutes should be started at t-2:30 assuming you can full throttle it and your craft doesn't lose weight as it burns...

Coast up to your destination and then burn retrograde at periapsis blah...blah...blah if you got to the Mun and Minmus the you know this bit.

Profit.

Good luck, you got dis!

Edit: The post above mine is the sensible and efficient way of doing things, mine has worked fine for me but requires some over engineering of fuel and delta v.

Not to mention a metric crap-ton of wait/warp time if you're aiming for Duna or beyond, but whatever works.

There's also a handy KSP planetary transfers app for iPhone or Android, if you just need a quick angles reference, which after a few runs really does get easy to use alone.

[TehUndeadMerc]

Well if I knew what angles to burn from based on a specific orbit then I'd do that (I don't have a cell though)

[Monkeh]

I was thinking about such design - You should have tried pulling up the legs of the lander for the moment making it sit on the rover.

I hate you because I'm too stupid to have thought of that...

Not to mention a metric crap-ton of wait/warp time if you're aiming for Duna or beyond, but whatever works.

Waiting for window / waiting in the sun's SOI = same thing?

I don't know, but I hear people say they were waiting for a window, I just wait in the sun's SOI. Does it turn out to be the same amount of time give or take?

[Soda Popinski]

Well if I knew what angles to burn from based on a specific orbit then I'd do that (I don't have a cell though)

Angle isn't as important as knowing when to leave. As far as the angle goes, just known if you want to go to an outer planet, like Duna, you need to set your maneuver node at sunset (assuming counter-clockwise orbit as viewed from the North). This gives you the additional speed from to add to your heliocentric orbit. The opposite is true to go to an inner planet, leave at sunrise, to help bleed off speed to drop you to a lower heliocentric orbit.

You don't need a cell phone to use the web version of KSP Launch Window: http://alexmoon.github.io/ksp/

[Deadweasel]

Waiting for window / waiting in the sun's SOI = same thing?

I don't know, but I hear people say they were waiting for a window, I just wait in the sun's SOI. Does it turn out to be the same amount of time give or take?

It's not, because when you're in flight and outside Kerbin's SoI, you're now moving in your own solar orbit, and will often have to wait longer to get the window (the period of time when your target is at the right angle, and it's optimal to launch). At least if you wait to launch, you can more easily predict where you need to be when you burn, instead of guessing and hoping that you'll eventually get the intercept you want.

Well if I knew what angles to burn from based on a specific orbit then I'd do that (I don't have a cell though)

In that case, there are also a few different web apps out there that will help you figure those out too!

My personal favorite before I discovered the phone app is this, which does the exact same thing, with visuals and everything!

http://ksp.olex.biz/

It's almost a facepalm moment when the little lightbulb goes off over your head, and you suddenly realize how planetary transfers work.