Doctor Who Wheel of Ice

"The Wheel of Ice: a ring of ice and steel turning around a moon of Saturn, home to a colony mining minerals for a resource-hungry future Earth. Aboard the Wheel the second Doctor, Jamie, and Zoe find a critical situation - and three strangers who have just turned up out of nowhere look like prime candidates to be accused of sabotage. The Doctor finds himself caught up in a mystery that goes right back to the creation of the solar system."