UFO: Flight Path (Episode 15)

Paul Roper is a SHADO technician with a pretty, younger wife and aliens have threatened to kill her unless he passes on to them cryptic computer co-ordinates, the possession of which will allow them to make an undetected attack on the Moonbase. Colonel Freeman discovers what Roper has been doing and Roper asks for the opportunity to make amends by undertaking a dangerous mission to the Moon to stop the attack.