|Portrayed by||Michael Billington|
|Occupation||Test Pilot[N 1]|
|Significant other(s)||Virginia Lake|
A former test pilot whose plane was critically damaged when SHADO's Sky One intercepted and destroyed a UFO in close proximity to his jet. Foster's subsequent persistent investigation of the incident threatened to expose SHADO's existence and Straker considered having him killed, but instead was impressed enough with Foster to offer him a position with SHADO (chronicled in the episode "Exposed"). Foster appears to be somewhat of a protégé of Straker's, as he is shown in a number of major positions. He is Moonbase Commander for a time (substituting for Lt. Ellis), is assigned to SkyDiver for several months, and also receives a position of authority at SHADO HQ. He masquerades as one of Straker's film producers in the studio and enjoyed a brief relationship with Col. Virginia Lake. Foster has the unique distinction of having once befriended one of the aliens, though he could not prevent him from being killed by SHADO personnel; his overall demeanour became noticeably more cynical after this event (chronicled in the episode "Survival").