Indicia reads: JET POWERS. No 1 (A-1 No. 30). The date entered in the "On Sale Date" field is the copyright date derived from the actual Library of Congress copyright documentation (available on www.archive.org).
Space Ace; The Keeper of the Sands (death); The Desert Devils (villains); Monster Robots (villains, some die)
Space Ace is on the trail of some space robbers, who are shooting down cargo planes over Mars. It seems that whenever cargo liners flew over the area where the robots were, their photoelectric cells were activated and the robots went on the attack. Space Ace discovers a now deceased "Keeper of the Sands", whose job it was to keep the robots in check, had passed away, but his control panel was still active.