John Mathewson
Government Aide
General
Scientist
Lab Assistant
Paul Stephens
Elizabeth Stephens
Jenny Anderman
Science Teacher
Roland (as Abe Unger)
Max (as Robert Leonard)
Tennis
Craig
Emma
Terry
Local FBI
Jenny's Parent
Jenny's Brother
Jenny's Brother (as Arthur DeCheser)
Lt. Col. Conroy
Conroy's Lieutenant
Eccles (as John David Cullum)
Moore
Price (as Charlie Fields)
Saito
Halley's Comet Kid
Laser Efficiency Kid (as Richard Cardona)
Flirting Kid (as Heather Dominic)
Flirting Kid
Registrar
Cabbie
Injection Doctor
FBI (as Alec Massey)
FBI
Barbara Collins - TV Reporter
Kerry Donovan - WBNG News
Command
Electronics
Computer
Interrogator
Interogator
Helicopter Pilot
Radiation Controls Officer
Night Guard
Relief Guard
Howard
Day Attendant
Day Security Receptionist
SWAT
SWAT (as Dan E. Butler)
Local townsperson (uncredited)
Mary (uncredited)
Computer Operator (uncredited)
Teen at Science Fair (uncredited)
C-4 Guy (uncredited)
Extra (uncredited)
Science Fair Kid (uncredited)
D.O.D. Man (uncredited)