In the near future, a space station dubbed Earth II is built for the purpose of scientific research and world peace. However, that peace is shattered when the Chinese send up a nuclear bomb that is orbiting just a few miles away from the station. Can the crew disarm the bomb before it detonates, not only destroying the station but setting off World War III?

Gary Lockwood
as David Seville

Scott Hylands
as Jim Capa

Hari Rhodes
as Dr. Loren Huxley

Anthony Franciosa
as Frank Karger

Mariette Hartley
as Lisa Karger

Gary Merrill
as Walter Dietrich

Inga Swenson
as Ilyana Kovalefskii

Edward Bell
as Anton Kovalefskii

Lew Ayres
as President Charles Carter Durant

Brian Dewey
as Matt Karger