Stephen Collins

as Self (archive footage)(1 ep)

as Philippe Delatour(6 eps)

as Gene Porter(22 eps)

as Mr. Harter

as Reed Wallace(1 ep)

as Dr. Dayton King(20 eps)

as Self(1 ep)

as Mr. Benson

as Joe Preston

as Dancing Alien

as "The Captain" Montgomery(4 eps)

as Joe

as Ambassador Walker

as Charlie(1 ep)

as Bruce Mathis(2 eps)

as Walter Bernard Sr.(1 ep)

as Self - Guest(1 ep)

as Self(1 ep)

as Joseph A. Ball

as Self(1 ep)

as Self(1 ep)

as Gardner

as Dan Carlin

as Mr. Maris

as Pierson Bartlett(1 ep)

as Tony Maychek / Earthmover (voice)(1 ep)

as Sam Sadwich

as Self(1 ep)

as Sam

as Aaron Paradis

as Eric Camden(243 eps)

as Tom Aiken

as Bill Bartrand

as Adam Graham

as Roger Billingsley

as Ashley Wilkes(2 eps)

as Dan Broderick

as Clee Donovan

as Jack Fremont

as Gerald Bender

as Dan Broderick

as John Fitzgerald Kennedy(3 eps)

as Stephen Dallas

as Attorney

as Capt. John Deason

as Shane O'Neill(4 eps)

as Billy Grenville Jr.(2 eps)

as Marty Phillips

as Dr. David Lowell

as Warren Cox

as Peter Hatten

as Dr. Jim Eiseley

as Todd Fields(1 ep)

as Billy Lee(3 eps)

as Jake Cutter(22 eps)

as Karl Hanke(2 eps)

as Josh

as Larrabee

as Greg

as Pete Casimir

as Decker

as Michael Hillyard

as Young Barry

as Michael

as David Spaulding(3 eps)

as Steve Carmody(1 ep)

as Hugh Sloan

as Agent Donald Nash

as Morton Fullerton(1 ep)