Voyage to the Prehistoric Planet (1965)

From a lunar space station, professor Hartman (Basil Rathbone) leads a team of astronauts and scientists to explore the faraway planet Venus. Dr. Marsha Evans (Faith Domergue) is assigned to the lead ship, Vega, while other teams follow on ships called Capella and Sirius. After an asteroid attack destroys Capella, the team's communications are cut off. The Vega team sends John the Robot (John Bix) to investigate Venus, while the Sirius team lands and makes a startling discovery.