For this post though we are returning to a specific episode of the original run - season three's Flight into the Future, the eighth episode that first aired in 1967. This story features two Destination Moon style suits which may even be the originals or at least a very accurate reproduction.
What's particularly interesting about this spacesuit though is that's its an ensemble of very mixed origins because while the suit may be from 1950, the helmets are from 1966's Way...Way Out. They have been modified to reflect the 50's aesthetic but that actually appears to have been done for an earlier Irwin Allen production; episode two of The Time Tunnel. There is lots more to be said about this but at the risk of repeating myself its perhaps best to follow the link and read all about here:
The Time Tunnel - Episode 2: One Way to the Moon (1966)
or go here:A Suitography of the "Way... Way Out" Spacesuit (1966 and onwards)