Kerbal Plan B

[Rhino1998]

I was building an orbital construction ship with Romfarer's Lazer system, the orbital construction mod, and KAS when I ran into an unexpected problem:

My ship did not have enough Delta-V to reach Munar orbit. With its spare parts tank empty, it had over 2000 Delta-V, however, with its 150 ton spare parts tank, it only had 500 DV.

Being a well equipped kethane mining base, I have plenty of spare parts to jury rig something with the lazer system's kerbal building abilities, but for the life of me, I cannot seem to get enough DV to reach orbit. It only needs about 400 DV more, because once in orbit I can construct a full fuel tank and siphon from that.

The full base

The ship in need with the assembly rover nearby

As you can see, I already tried to attach a tank to the top, but it did not provide sufficient DV so I removed it. So, I come to you, community, can you figure out a way I can rescue this mission. Preferably without requiring additional launches. Any help is appreciated greatly.

Edited May 18, 2013 by Rhino1998