While flying a routine orbit of Saturn, you are caught in a radiation storm, which forces you into the rings and drains all your ship's energy. You make a forced landing near an old mining base and set off in search of dilithium crystals to fuel your ship.
Notes
The Oric version was released by Mikro-Gen in 1983 on the same tape as Return to Earth. The C64 game was unofficially remade by Brando Denicora as Saturn's 10 Moons and published by ICA (Italien Computer Adventures) in 1988.
"The game was later unofficially remade as Saturn's 10 Moons."
Why? It was already available for the C64 and it's not a particularly good game.
I haven't gotten the foggiest. But the remake is out there.