Would it be possible for the space shuttle to make the trip to the moon?
The shuttle’s navigation computers and life support systems could support a mission to the moon easily. With the Extended Duration Orbiter (EDO) pad in the cargo bay, there would be enough supplies for a 16-day mission. However, as you point out, the ET (external tank) is discarded on the way to orbit. If you could some how dock with a fuel tank, the shuttle could easily travel to the moon and back. 4.5 million pounds of thrust is plenty for TLI and to reenter Earth orbit on the way back. (The shuttle would have to reenter Earth orbit before landing. The thermal protection systems are designed for a reentry from LEO at 17,500 mph — not a direct return from the moon at 25,000 mph.) Another problem you’d have is landing on the moon. The shuttle is not equipped for that sort of landing. So, you’d have to carry a small lander in the cargo bay. It’s a fun idea, but it isn’t really practical. It would be a lot easier to launch a proper moon mission using 3 or 4 shuttle missions to carry the
