First, a note. ZOMBIES OF THE STRATOSPHERE marked the science-fiction film debut of actor Leonard Nimoy. He plays Narab - one of the Martian "zombies" - and actually has a few lines in the film. I was kind of surprised Amazon didn't list him as an actor - since Nimoy's presence might actually lend to increased sales of this DVD set.
In the space of three years (1949-1952), Republic Pictures put out 3 "rocket man" serials - all using the same rocket suit for the hero. Only the hero's identity changed. The first of the 3 was KING OF THE ROCKET MEN - starring Tristram Coffin as the hero in the suit, Jeff King. Then came RADAR MEN FROM THE MOON - starring George Wallace as the hero in the suit, Commando Cody. Finally, six months later, came ZOMBIES OF THE STRATOSPHERE - starring Judd Holdren as the hero in the suit, Larry Martin. All three are worthy serials and all deserve recognition. But only 1949's KING OF THE ROCKET MEN episodes achieved after-market success - later compiled into a standalone film release titled LOST PLANET AIRMEN, released in 1951.
EDIT - Originally, I said that 1952's RADAR MEN FROM THE MOON was turned into a 1953 TV series titled COMMANDO CODY - SKY MARSHALL OF THE UNIVERSE. Not true. While the "Commando Cody" name made the transition to the series, the part of Commando Cody was played by Judd Holdren (Larry Martin in the ZOMBIES serial) and the story line was significantly different. Thanks to George Fergus who pointed that out in his comment.
The plot of ZOMBIES OF THE STRATOSPHERE, even now, could be believable. An alien race (Martians) is dying and their planet is slowly becoming unable to support life. To remedy this, the Martians come up with a delicate but ingenious plan. At a certain time during Earth's rotation around the Sun, the Martians discovered that they could "blast" the Earth out of its orbit - and move Mars into Earth's place. To do this, they need to place a super-powered hydrogen bomb at a strategic point - detonating it at a precise moment.
Unfortunately for them, a group of scientists (Larry Martin, in particular), has become curious about certain crimes perpetrated in order acquire the material to build the bomb. And he, and his rocket suit, are on the case.
All 3 serials were made available on VHS years ago. The first 2 are already available on DVD. This release of ZOMBIES OF THE STRATOSPHERE completes the process of putting good quality DVDs of all these serials in the public's hands. If you're a fan of Republic serials (or the "rocket man"), I urge you to get all three serials on DVD. You'll enjoy all three immensely.