Zombies of the Stratosphere is a 1952 black and white Republic Studios serial directed by Fred C. Brannon, with a screenplay by Ronald Davidson, and special effects by Republic's Lydecker brothers. It was intended to be Republic's second serial featuring "new hero" Commando Cody and the third 12-chapter serial featuring the rocket-powered flying jacket and helmet introduced in King of the Rocket Men (1949). Instead, for reasons unknown, the hero was renamed "Larry Martin", who must prevent Martian invaders from using a hydrogen bomb to blow Earth out of its orbit, so that the Martians can move a dying Mars into a much closer orbital position to the Sun.

https://en.wikipedia.org/wiki/Zombies_of_the_Stratosphere

The freaking poster is amazing:

I mean, c'mon!

Why is Spock on the thumbnail?

Please, it's obviously Sarek!

Because this was one of Leonard Nimoy's early acting roles.