This is an interesting idea. The SLS is Shuttle derived technology. So the same thing could be done with the external tank (ET) of the SLS. It really wouldn't take that much to make the tech resusable. What was true of the Shuttle is still true with the SLS. Why would it not take much?
It's one of the cool things about the Shuttle that people may have overlooked. When the Shuttle dropped its External Tank, it was only at 98% orbital velocity. The point being that it needed a bit more boost to get to orbit. So the ET was dropped into the Indian Ocean in order to reduce mass, and the OMS thrusters took the Shuttle to orbit. The OMS thrusters weren't all that powerful, but didn't need to be. Likewise with the SLS. If OMS thrusters were added to the system, it could get to orbit. Or if more fuel was added somewhere in the architecture. Maybe with the boosters. It wasn't done during the Shuttle Era, but why now?
They didn't have any plans for such a big object in space, so the easiest thing to do was to expend it. What a waste. Each launch costs over a billion dollars. If all the pieces were reusable, the system could be cheaper. But it isn't cheaper. It's horribly expensive.
Saturday, November 27, 2010: The original post follows:
Let's assume that you could get the ET to L1. How can the materials from the tank be used to set up a Moon base?
Here's the internals of the tank again. From right working to the left,
there is the liquid oxygen tank,
then the intertank,
followed by the big liquid hydrogen tank.
Let's start with the oxygen tank. It's the smaller of the two propellant tanks and it looks like a convenient shape. Could this tank be fashioned into a lander of some sort?
If it were possible, attach legs and rocket engines to the bottom of this tank. There are some big rocket nozzles at the bottom of the big hydrogen tank. Detach those and reattach them to the oxygen tank. Use the intertank as material. Use the hydrogen tank as a solar furnace, melt down and/or cut the metal needed for the legs and attach it below and/or around the rocket nozzles at the base.
How could that be done? Make some cable out of the intertank and a harness to tighten up the entire assembly into one tight package. The harness for the cable would span between the top of the cone of the oxygen tank down to the leg assembly. At the cone, it would be a circular ring where the cable could fit. The "leg" assembly could be just the round intertank with spaces cut out of round cylindrical shape of it. Cut out the middle of the intertank and with all the spaces cut out, you could have room for the rocket nozzles to fit into that space.
There would be enough space between the rocket nozzles and the intertank to give clearance at the lunar surface. If the nozzles are too big, maybe you could use just one of them. You would need a way to secure the nozzle to the intertank and that assembly to the oxygen tank with the cable and harness system described. Hook up the rocket nozzle to some smaller fuel tanks that may be fashioned out the remaining material, or brought up from Earth.
If this contrived contraption worked, it would be left on the lunar surface and serve as the first piece of a lunar base.
