Yes! That was it. Great serial.
Also one with Gene Autry about alien invaders. I think they were called “thunder riders”. It was way ahead of it’s time.
‘King of the Rocket Men’ was the original...preceded ‘Commando Cody’by a few years. Great stuff...the evil Dr. Vulcan trying to flood Manhattan with his doomsday ‘Decimator’ device...the Mayor Lindsay clone; years before the real one came on the scene.