Commando Cody: Sky Marshal of the Universe
This was a follow-up to Radar Men from the Moon, and featured the same hero, Commando Cody. Cody uses his rocketpack to fight villains of all kinds. Though this was actually made for TV, it ended up being shown in theaters as a serial anyway. Serial 'purists' object to it because it lacks the cliffhanger endings characteristic of regular serials, but the episodes are all part of one big story just like other serials, rather than separate stories like most series of the time.