Thoughts on a Booster

[capi3101]

Hey all,

So, I'm getting ready to do my third reiteration of my interplanetary ship design. It's basically three modules docked together in space - a main thruster module, a supply module (the one that carries most of the gas; more that one of these gets me further), and a lander. The first design was a nice, light design; used only a single docking port, so it wobbled like crazy and I couldn't steer it. Second design was beefier - too beefy as it turned out; my computer couldn't crunch all the parts without serious lag.

So this time around I'm going back to my first design but replacing the docking ports with the heavy 4 Clamp-o-tron docking port design I've seen floating around here on occasion. This has given me a new problem: I am having problems attaching my existing booster to the redesigned modules. Particularly the service module - it's got these docking ports on both ends. Has anybody worked with that design and successfully got a booster attached to one of those ports, or can anyone help me design a booster that will get the whole load up into space? It has to be able to lift at least 45 tonnes to a 100k orbit and has to be able to de-orbit itself afterwards. Brownie points if you can get it attached reliably attached to the ports in such a way that it'll come off again.

I have tried adding small stack decouplers to the ports and adding a corresponding docking port to the booster part; in the first case the booster wouldn't attach and in the second the docking ports refused to undock.

Thoughts?

[CalculusWarrior]

Good idea, I utilize a similar design, exceipt that I prefer having the engines attached to the fuel module: that way the ship doesn't flex as much. I also preattach any extra goodies for the mission, such as probes or rovers to that stage. Then, I dock the lander and the crew living quarters section, and I'm off!

Here's a pic of my Duna interplanetary mission:

The lander is on the side closest to Ike; the radioactive exhaust from the engines barely misses it when throttled up! On the other end is my Orion-styled Crew Vehicle, which holds the crew on their voyage to Duna.

The large pod near the middle is one of my rovers, encased within an 'aerodynamic' shell.

[capi3101]

There is a fuel tank attached to the thruster module; the service module is specifically for the purpose of extending the craft's range (math says I should be able to do a full round trip to Tylo with four service modules attached as I've designed it).

Forgot to mention that - the thruster/service module combos are designed as round-trip transfer stages, which is the main reason why they're so heavy. The thruster stage is meant to be re-usable; just undock and deorbit spent service modules, dock fresh ones and off you go.

[Temstar]

A deep space engine using the quads? Why one already exists:

It's here:

http://forum.kerbalspaceprogram.com/showthread.php/24990-0-19-1-Orbital-Propellant-Depot-Olympus-II

Edited April 28, 2013 by Temstar

[capi3101]

Ah...that's your ship/part/idea (probably) I swiped......thanks.

Functionally the Olympus booster is what I wound up building once I got the quad-port attached; the other differences appear to be mostly cosmetic. Mine looks clunkier.

The booster units for one should function for the other; definitely will have to take yet another look at the Olympus. I will mentioned that I did finally figure out a solution for getting my Dystopia 7 booster attached; the TR-XL Stack Seperator did the trick. Aside from leaving another piece of space crap in orbit, I'm happy with that solution.

So quick question - how's the best way of going about undocking one of those quad ports? I've had some issues with that.

[Temstar]

For undocking just undock each of the four docking ports in turn. Once undocked the two docking ports facing each other will go into a "undocked" state and will not go into a "ready to dock" state until you either backed them away to some distance apart, or if you exit to tracking station and go back to the ship. So when you undock the last of the four docking ports the ship will separate into two.

[capi3101]

Okay. Thanks. I did get two craft undocked today; it was occasionally tricky finding the correct port to select.