A range of questions from interplanetary travel to rovers

[LFC908]

Now before we begin I'm going to get this out the way; I've had the game for a few months but played it on and off! Yes I have been using mechjeb... don't start a war over it.

Anyway basically I've had some problems recently. I can get to mun and minmus easily but with mechjeb I literally cannot get to another planet. It keeps saying the next node is like 220 days and shows no intercept, What am I doing wrong? Then my next question is how to dock? I have the first part of my Kerbal Space Station up (KSS#1) but I don't know how to begin even docking the second part. Then my last question is rovers; How would I deploy a rover to the surface of a moon or planet? (mun for example) thanks for your help in advance

Edited September 18, 2013 by LFC908

[capi3101]

Several questions there...

First one: for figuring launch windows, I highly recommend the Launch Window Planner site. Folks use it Mechjeb or no.

That didn't quite address your question though, did it? Basically, if you finish your transfer burn and don't get an intercept, you'll have to plan for a correction burn. I usually put mine about halfway between Kerbin and the target. Just fiddle with the node until you get an intercept; the earlier you correct the less delta-V you spend, and be ready to pull radial burns if absolutely necessary.

Second one: how to dock. That question gets asked at least once a day around the forums. Sarcastic answer is "very carefully", but of course, that's not helpful. I'd suggest trying out the Gemini 6A/7 tutorial on the wiki. I've written a longer procedure for both rendezvous and docking before; I'll have to fish for those and edit this post later.

Here's how you rendezvous.

After that, you want to get your relative velocity to the target down to zero once you're within 100 meters. Be prepared to start braking early if you've got a heavy ship or if you're strictly on RCS.

One you've zeroed, aim at the pink meatball icon on the nav ball and slowly thrust ahead (to about 1 m/s tops).

At fifty meters, zero out your velocity, adjust your aim and thrust ahead (no more than 0.5 m/s at that point). Within 100 meters you need to have the specific docking port you're aiming at targeted.

At twenty meters, zero out your velocity, adjust your aim and turn on SAS. Switch to the target, aim its docking port towards the first craft (target it and set your control point as the docking port first). Switch back to the first ship and thrust ahead slowly.

At ten meters, zero out and adjust your aim one more time. Turn both craft if necessary. Thrust ahead with the first ship.

If you're not spot on, your two craft may dance about a bit as they come into contact. That's normal - do nothing and just let them settle on their own. When the view shifts, you're docked.

Third one: Again, this is a topic that gets asked fairly frequently and there are varying schools of thought. I'll have to hunt for pics of how I've done it...right now I'll post so I don't get ninja'd...

Skycranes are fairly common, though - basically it's just a lander module that carries your rover underneath or on the sides, it has enough delta-v to get the rover close enough to the target's surface to drop them or land; if it drops them, it usually crashes before making orbit again. Slapping them on the sides of a lander works too. Usually it's a good idea to bring at least two rovers to keep the load balanced. Or, if you've got a single rover that is itself large/unbalanced, be sure to add a counterweight somewhere on the skycrane - my first Hellhound 7 skycrane utilized a counterweight, the second one just packed two rovers and has proven to be much easier to fly. I think I've got pics of that but imgur's being fussy this morning.

Good luck; if you have more questions, ask.

Edited September 16, 2013 by capi3101

[Synapse]

1. make sure mechjeb has auto-warp enabled. 220 days is a normal time for a good window

2. watch videos on youtube for orbital rendesvous and docking

3. you can use a skycrane or attach parachutes to your rover

[Monkeh]

The easiest way to get some nice rovers on your craft is to use the sub assembly manager from the spaceport. It lets you build a rover and then save it. Once you start the main ship you can load the sub assembly and stick it on. I started with a small girder as the principal part as the principal part HAS to have a free node to attach it to anything. Then I made a little rover and shoved it onto the side of my fat lander. It decouples using some docking ports and slides down the little ramp. Here it is:

I've had a parachute rover shoved on top for when I went buggying on Laythe:

To get to other planets I just play with the maneuver nodes. Add some delta v until the projection gets close to the orbit of the planet you want and then move it around and tweak the delta v until you get an encounter. Watch for the little nods moving round, one should say closest approach and target position at closest approach. Get them to intersect and hey presto, badda boom, etc.

Docking requires RCS fuel and thrusters. Place the thrusters so they point left/right, up/down and forward/backward. When you get close engage RCS and drift in. To orientate yourself don't be afraid to turn off the RCS and use the SAS to spin round and then back to the RCS for the gentle push together of the docking ports. Make sure they're the right way round as well. Easy to get them backwards.

Good luck, experiment and practice. That's the way.

[blackfire83]

There are many methods of landing a rover. On a planet/moon with an atmosphere, you could just jettison the rover from orbit and use parachutes to land it. As for the Mun and other bodies without atmosphere, you'll need to land them with rockets or RCS. Here's one of my favorite methods:

I love Skycranes! This one is at the perfect height so that the rover can actually re-dock with the Skycrane and then be moved to another location.

Edited September 16, 2013 by blackfire83

[LFC908]

Thank you for all this really in depth stuff! Really appreciate all the effort you went in to! I can now confirm I have a probe orbiting the planet Duna, a Rover on the Mun and I have three parts of my Space-station docked in kerbin orbit! Thanks for the help guys (shame there isn't a rep system here, I'd rep you all )

[capi3101]

There is a reputation system - it's the little star-shaped badge in the lower left of each post (right next to "Blog this Post")