When the original Gundam TV series was compiled into the three movies, many things deemed too silly were dropped from the story. In this case, the Guntank, flying through space was cut and it's pilot Hayato was given a Guncannon to use in the third movie.

Now since the Guntank was built using the modular coreblock system, it seemed an easy proposition to replace the tank's ground-based treads with a more space-worthy base. Thus is born the Guntank / space booster. It's really simple. I just took the treads off and added four round thrusters to each corner. Now there we have it--a space going Guntank. With those thrusters and external fuel tanks this would probably be a fast and effective space vehicle.