This Island Earth (1955)

 Dr. Meacham is chosen along with others by the inhabitants of the planet 

Metaluna to do research that will help save their dying planet. However, 

an evil scheme is uncovered by the suspecting Dr. Meacham when he discovers 

the Metalunan's plan to take over Earth. Dr. Meacham then escapes an 

exploding Metalunan built Earth lab along with Dr. Adams only to be kidnapped 

while flying away in a small plane. A flying saucer wisks both the scientists 

off to Metaluna where they are held accountable for blowing up the Metalunan 

Earth lab during their escape. They later escape there with the help of Exeter 

the friendly Metalunan. Metaluna then self destructs and the Doctors make it 

safely back to Earth, which is saved from Metalunan invasion. (IMDB holland)

Add Robert Nichols and Rex Reason