Show me your refueling depot setup!

[OddFunction]

Hello!

I am really, really failing at making stations. Like bad. I am competent enough to make a suicide mission to Eve or Duna but this whole docking/orbiting refuelling depot thing is driving me nuts.

Basically I tried going too big too quick. Had a couple mill layin around and decided, go big or stay home.

With some help from my friend(s) the twin boars, I put up one ridiculous starter hub with a science station + UKS greenhouse + docking ports + electronics + life support, everything. That was easy. Next I launched up a big orange tank with docking ports and set out to dock it to my hub.

D--------------------------D

D| Orange Tank_____|D

D--------------------------D

And I discovered, it is the most difficult thing ever to dock two huge objects together. I tried until I ran out of fuel. Then I launched another orange tank, and tried again. I have Docking Alignment indicator, but the problem is I can never manuever fast enough, even with RCS, to get the monster to line up and slowly connect. I just can't.

So now my idea is to put up 1 big fuel tank with docking ports, and then dock it to a decent sized KW Rocketry tank(a full ship on its own), and use it as a mule to haul fuel between ships. Before I do that though I wanted to see if any of you had better set ups or ideas?

Edited June 3, 2015 by OddFunction

[Mister Dilsby]

It should not be that hard, even with big parts. Are you in an equatorial orbit with your docking ports aimed north and south? If your ports are not aimed that way relative to your orbital path, then they're going to rotate around the N-S axis as your ships orbit. Could that be part of the problem?

For reference, here's my Minmus setup. There are two sets of four ports each. You're seeing an 'ore piggie' arriving to the south port on the nearer set. The far set has longer booms and is reserved for large visiting ships. If I need to use one of the ports that are presently oriented E-W, I rotate the station 90 degrees so that those ports are pointed N-S

ETA: You'll note the absence of any alignment indicators or other helpers Procedure is to get close visually, aim the docking port N if you are docking on a S-facing port, then kill relative velocity to a few .1 m/s and patiently adjust until everything is lined up.

Edited June 3, 2015 by Kuzzter

[Chaia]

My advice is to start small. Are you capable of docking 2 small objects? Try this to start with. Then start to dock bigger objects together.

If everything does not help at all, you could still use Mechjeb docking computer. ;-)

[OddFunction]

My advice is to start small. Are you capable of docking 2 small objects? Try this to start with. Then start to dock bigger objects together.

If everything does not help at all, you could still use Mechjeb docking computer. ;-)

I can definitely dock 2 small ships together its just the big ones that are tough. I'm really really good at getting intercepts too. I just wish there was a 3.75 or w/e docking port.

It should not be that hard, even with big parts. Are you in an equatorial orbit with your docking ports aimed north and south? If your ports are not aimed that way relative to your orbital path, then they're going to rotate around the N-S axis as your ships orbit. Could that be part of the problem?

For reference, here's my Minmus setup. There are two sets of four ports each. You're seeing an 'ore piggie' arriving to the south port on the nearer set. The far set has longer booms and is reserved for large visiting ships. If I need to use one of the ports that are presently oriented E-W, I rotate the station 90 degrees so that those ports are pointed N-S

http://i.imgur.com/aVYwWrk.png

ETA: You'll note the absence of any alignment indicators or other helpers Procedure is to get close visually, aim the docking port N if you are docking on a S-facing port, then kill relative velocity to a few .1 m/s and patiently adjust until everything is lined up.

I have not orientated my ports N - S, I will try that now. I never knew it made a difference, but thinking about what you say makes sense. Especially since knowing where they'll be on the navball all the time is incredibly useful.

Now I'm just sittin in the VAB tweakin stations and fairings @_@

[YourEverydayWaffle]

Ha. Cower in fear at the awesome glory of my superstation!

I made it a while ago, but I think I built it in 5 or 6 flights, the heaviest single flight being the section in the image from the cupola to the large docking port in the middle of the trusses. No hyperedit used, I can post pictures of the huge lifter if anyone wants them. This was built as a superheavy probe carrier and multi use station, but I've used it for refueling quite a few times. Pretty proud of this one.

The picture doesn't do it much justice due to the quality, but the trick I found to work was using a HUGE amount of RCS. There is a massive amount near the tail.

You mentioned making a mobile refueling setup. This thing is mobile (designed for a large scale Duna mission, project put on hold), but is a serious fuel guzzler, and was built to accept refueling along the way to its' destination. Not very practical for what OP is looking for. In my opinion, I think you should go for a large fuel storage setup, put it in a good orbit, and use smaller "slaves" to detach and carry fuel to where ever needed, if you really need to do that. If you still have issues with docking, I recommend doing some sort of asparagus setup with RCS tanks. RCS was really what made this mission possible, because I packed on a massive amount. And remember, practice makes perfect, so if you can, try it on a smaller (or cheaper) scale and get yourself more familiarized with the RCS tranlation controls. Hope this helped.

Edited June 3, 2015 by YourEverydayWaffle

[ajburges]

There are a few complications in large docking.

Wobble. Large modules can have issues where force introduces wobbles. This makes precise alignment impossible. You will need to slow down and let wobbles dampen out after every input you give or add moar struts.

Translation TWR. 4 kN of thrust (4 bocks or 2 linear thrusters) is the same as 2 Ants. You have no acceleration for maneuvers applying that to a massive module. Zero velocity and go slow (see next issue) or add more thrust (and risk the previous issue)

Time. It's okay, I'll just take longer! Except inclined circular orbits intercept every half period. In LKO that's every 15 minutes. Worse, every quarter period sees either relative position or relative velocity reverse. Non-inclined orbits bring back rotation as an issue.

[Warzouz]

I usually set the docking ports area for the ship as far as I can from the solar panels and extension docking ports.

Here is a space station around Laythe (beta 0.9) for multiple moons exploration (while return ship is docking). That space station was assembled there not in Kerbal SOI (13 launchs, including the 6 landers).

Here is my current space station in LKO (1 launch, not counting the plane obviously). Again, the docking rings are far at the bottom and extensions are at the top.