Stargate S01E01 - 'Air' Part 1
When Icarus Base is attacked, it's inhabitants are forced to flee through the Stargate. The base was created on a distant planet to take advantage of a powerful energy supply located there. Their goal is to try and determine the purpose of the mysterious ninth symbol of the Stargate, which they've never been able to lock in. In going through the Stargate, they are transported not to Earth but to a very old apparently uninhabited spacecraft. With the group's commander injured, Lt. Scott and the chief scientist - Dr. Nicholas Rush - lead the exploration of the craft. Several areas of the ship have been damaged but it is basically functional. They are able to learn that they are, in fact, billions of light years from Earth.