Odyssey 5 is a Canadian science fiction series that first ran in 2002 on Showtime in the United States and on Space in Canada. The premise involves five space travelers who witness the destruction of the Earth; they are given the opportunity to travel to the past to identify and prevent the cataclysm. Wikipedia
(V.O. intro from every episode except pilot)
Chuck Taggart: We saw the Earth destroyed, and in a heartbeat everything and everyone we knew was gone. There were five of us, the crew of the space shuttle Odyssey, and we were the only survivors. A mysterious being who called himself The Seeker rescued us and sent us back in time. And now we have five years to live over, five years to discover who or what destroyed the Earth, five years to stop it from happening again.