UFO - Season 1 - Eps 11: Close Up
Straker gets approval from above to build a probe with a camera that will track a UFO back to its home planet. Inexplicably, the Earth technology is capable of following a UFO travelling 8 or 9 times the speed of light and follows it home. The episode ends with a SHADO guy trying to convince Straker that they were wasting their time, even though they picked up some great pictures of the planet.
About UFO

Title: UFO
First Air Date: 1970-09-16
Last Air Date: 1973-03-15
Status: Ended
Rating: 7.6/10 (from 45 votes)
Language: EN
Seasons: 2
Total Episodes: 26
Network: Associated Television
Genres: Sci-Fi & Fantasy, Drama, Action & Adventure
Production Companies: Century 21 Television, ITC Entertainment
Synopsis
A secret, high-technology international agency called SHADO defends Earth from alien invaders.
Cast

Ed Bishop
Cmdr. Ed Straker