Basil Rathbone
Prof. Hartman, Lunar 7
Faith Domergue
Dr. Marsha Evans, Vega
John Bix
John the Robot
Gennadi Vernov
Andre Ferneau, Sirius (archive footage)
Georgi Zhzhyonov
Hans Walter, Sirius (archive footage)
Georgiy Teykh
Dr Kern, Vega (archive footage) (uncredited)
Vladimir Yemelyanov
Cmdr. Brendan Lockhart, Sirius (archive footage) (uncredited)
Yuriy Sarantsev
Allen Sherman, Vega (archive footage) (uncredited)