Fuel transfer while on the Mun's surface.

[Valley]

After testing a theory on how to make sure a save file can survive a update (and trying to find ways to make a MechJeb free station while still using the Mod) I am thinking on what to do next.

I would like to land a probe on the Mun and put a fuel station in orbit. After that I would like to see how to place a few structures on the Mun. My problem is two fold:

1. Putting a fuel station in Mun orbit - which I have never tried even with MechJeb - may not have enough fuel to be worth it. If that seems unlikely I will need to find ways to land fuel tanks onto the Mun itself. Which brings me to the next problem.

2. Refueling with stock parts seems to have many problems. The big one seems to be that while you can test dock a F-Rover (my name of a Fueling Rover) to a lander on the launching pad doing so while on the Mun is another issue. Mun gravity seems to mess it up somehow and the two parts have a problem meeting. I have seen this problem solved by using RCS or playing with aircraft landing gear. Has anybody found a non-mod way to easily refuel while on the Mun? I was thinking of maybe having a Jr. Docking Clamp on the sides of the tankers, maybe attached to landing gear, to lower down onto the top of a F-Rover but that seems to be asking for trouble. And I wish to keep the part count down. Also the F-Rovers would also need to fuel visiting landers.

T-Rovers (Transport Rovers) would run on juice and be just for moving the Mun Base crew around so that isn't a problem. Just slap on a few solar panels or some reactors.

Any suggestions? Or is this just an engineering issue that everybody deals with in their own way?

PS - MechJeb II is turning out to be very easy to use and I think a twice as smart as the last one. Docking can still be a problem sometimes but it handles it well.

My Mod-Free station -

[Pyromaniacal]

Playing stock, I can't think of an easy, effective way to refuel ships from a Münar station. If you wanted to remain stock, I would recommend using an orbiting fuel station around Kerbin, as this would be the easiest place to rendezvous with after launch.

Not using stock, one of the easiest ways to transfer fuel would be using the Kerbal Attachment System, or KAS. ( http://kerbalspaceprogram.com/0-18-2-kas-kerbal-attachment-system-v0-1/ ) This allows various clamps, ports, plugs, or electromagnets to "dock" 2 ships together and allow the transfer of resources. If you wanted to use a different system that has no connections whatsoever and just kinda "beams" the fuel to another craft, you could use the Lazor System. ( http://forum.kerbalspaceprogram.com/showthread.php/9923-0-21-Lazor-System-v29-%28Jul-26%29?highlight=resource+transfer ). This includes several different useful things including docking cameras, resource transfer, guided flight, interplanetary transfer systems, and various weapons. A final option is the Infernal Robotics system. ( https://github.com/sirkut/InfernalRobotics for download) This uses a series of joints, elbows, hinges, and rotation joints to allow you to move a docking port into position to dock with a F-Rover. This does not solve the issue of getting fuel to the Mün.

Not using stock for the fuel issue, the best one I can think of is Kethane. ( http://forum.kerbalspaceprogram.com/showthread.php/23979-Kethane-Pack-0-7-3-Geodesic-grid-overlay-%28hex-map%29-and-other-scanning-improvements! ) This is a system that allows you to find deposits of Kethane, convert it to fuel, and send it where necessary.

Hope this helps!

[Dunbaratu]

I have had success with re-docking rovers to bases on the Mun, but the problem is that the heights MUST be exactly the same. The magnetic pull that pulls the ports together is strong enough to appear really powerful when you're drifting in space, but in space everything looks powerful (i.e. you can maneuver around with a really low TWR once you're up in space). In actuality the magnetic dock pull is actually quite weak and is not strong enough to counter gravity, even minor gravity like on the Mun. Therefore you end up having to manually get ALL the alignment right yourself, AND have everything at the right height.

If you have your rover, say, 2 degrees off angle from your base, the docking ports won't work. In space they would work like that but on a surface they'd have to pull the rover sideways against its wheels to pull it into alignment and they're not strong enough to do that.

The reason you can test on Kerbin and it works and it still fails on the Mun is that gravity pulls on suspension differently when it's weaker, and this causes the craft to rest at a different height on the Mun than it does on Kerbin. Sometimes i've been able to raise or lower the rover's docking ring by simply having a bit of RCS on it and using that to lift the nose of the rover up or down a bit until it grabs.