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[Finger]

[Super Wabbit]

As I get more comfortable moving around heavenly bodies, I keep experimenting with crazy heavy launch vehicles. I don't like the idea of sending Kerbals on long trips in cramped capsules so my latest build includes a habitat module and lander can (personal office) for each crew member and includes a dual stack of habitation modules for communal space.

In this case I was experimenting with the Quad decouple to get 4 Nuke engines on my transit vehicle. I assume I may be losing some efficiency but since I'm hauling so much fuel around, I'm inclined not to wait on 1hr burns to get to other planets. I haven't been able to find a way to attached stages below a quad decouple so I decided to use my Truss expertise.

You'll notice the remnants of the 8 radial decouplers on each of the 8 booster legs. That's right, there were 64 SRBs on this bad boy at launch.
Another angle just before separating the booster legs
Using the small srb decouple rockets makes for some pretty stage separation pictures here and here
Twin crafts meeting in high orbit

[Super Wabbit]

I decided to build a munar base. Engage iterative testing!

I came up with an interesting layout of stock modules. First step was to see if it could support itself: Static Prototype

Yes, room for 110 Kerbals.

Since it could support itself on Kerbin it would obviously work on the Mun. On to stage 2 of testing: does the decent stage have enough fuel for a soft Munar landing? Designing a lifting vehicle will be the last step. So I strapped a Main Sail to the bottom and enabled infinite fuel just to get to munar orbit. From there, I disabled the cheat and proceeded with a normal decent and landing. Munar Descent

Turns out I didn't have enough fuel for the descent stage and ended up enabling infinite fuel to make the landing. Almost there...

Even though my descent stage didn't have enough fuel I was still able to test the crew return capsule. The return capsule has just enough fuel to make the return voyage on it's own but makes for a very hot reentry. I'll probably strip down the return capsule so it has just enough to rendezvous with command type module in orbit thus lightening the whole vehicle.

[Super Wabbit]

So I've got my Mun Base design finalized. Just the base...

I need a lot of fuel to land this base. Unfortunately, conventional rocket design would make my moon base too tall for it's legs so I developed a Drop Tank system. Using the stock Truss and downward-facing decouplers, I can take advantage of the free space under the base's three spokes to add fuel. I thought this was clever of me. I guess I could have attached the decoulplers directly to the base but the Trusses add some much needed rigidity to the base.

Here is the Second Drop Tank Revision using a vertical decoupler to attach rocket stages underneath the bases three spokes. Since the drop tanks have no engines attached to them you have to monitor their fuel states manually to know when to drop them. I found this added a fun little element to the landing phase.

This view shows a failed ascent stage design. Notice the nuke engines hanging below the base's spokes. These are part of the transfer stage. Unfortunately they add a significant amount of mass to an already bloated design.

And another failed Ascent Stage that is an example of my original thinking of using symmetrical ascent stages underneath the spokes. I have plenty of space to add boosters but that is a double edged sword. I call these Spoke Boosters...the center of Spoke Boosters (the orange tanks) need to have struts connecting them to the central booster column. The boosters around each of the Spoke Booster columns would be designed to be jettisoned. Connecting a strut to a booster that would be jettisoned mid-stage would make an unstable vehicle.

Serious Group Photo
Silly Group Photo

I'm still trying to figure out how to get it to the Mun. The final version of the base with full fuel is about 180t. By the time I've added a transfer stage I'm pushing 250t. I have not figured out an ascent stage that can lift that. Joe's idea is that I refuel in Kerbin orbit. This is probably the best plan and I'll experiment with making the final ascent stage pull double duty to act as the transfer stage once it's been refueled. From a 100km Kerbin orbit, it only takes 841m/s of deltaV to get to the Mun. Anyone know of the approximate deltaV you'd need to circularize a 15km Mun orbit?

Also, am I correct in assuming that it takes ~4500m/s deltaV to get to 100km Kerbin orbit?

For those that didn't know: Mechjeb has deltaV stats for each stage that I've been using to help design everything. It really saves you time by not having to use trial and error to discover you didn't have enough fuel to get somewhere.

I just had a crazy idea: Design a space tug boat that would dock with the Mun base and provide just the deltaV to get to the Mun. Once the base has been put on a path to the Mun have it detach and return to Kerbin orbit. I guess that's not terribly efficient from the entire program's perspective but it would be efficient for the lander and it would be cool. I'm thinking that once it get's the base on a Mun encounter vector it could undock and place itself on a free return trajectory. That'd be cool.

[Finger]

That's a clever design, Wabbit. Although you used the infinite fuel to get it into orbit I'm surprised you were able to do it with so few engines. Rocket bloat seems like a typical hazard with KSP rocket designers.

One item I've seen others use and am just trying out now is the Kerbal Engineer Redux. It gives you stats for your rocket while you're building it. You mentioned MechJeb does this but I hadn't considered using it while building the rocket.

http://kerbalspaceport.com/0-18-1-kerbal-engineer-redux-v0-5/

Did you consider sending the base up in pieces and assembling it in space, or even on the Mun? I was thinking modular design would be easier to transport and land, but perhaps a single unit as you've shown is the way to go.

BTW, I reserve the right to "borrow" ideas from others frequently.

[Super Wabbit]

I did think about assembling the base on the moon but this particular design doesn't make this possible. Also, large crafts are awesome!