Episode #133 (according to the leader of the film) of the Daily broadcast of Space Patrol. If it is actually 133, it would have originally aired in September of 1950, probably.
Identification isn't certain because not very many episodes of this era survive.
Some points to help with identification:
They're wearing the original uniforms, so it's prior to June of '51. Buzz is there, so it's after May of 50.
The ship is called "Terra the fourth" here, though, as opposed to Battle Cruiser 100, which either represents a difference between the ship names used by different writers, or places these episodes sometime in Jan or Feb of 1951 (which is the first time Terra 4 was mentioned in the half hour show.)
I believe that this is from September of 50, and does predate the weekly show's debut in late December. I imagine it's one of the first episodes written by eventual series head writer Dick Darley
Here is episode 134 which would have aired the following day.
Let me know if you'd like to see these through my new telecine.