A runaway asteroid is heading to Earth. Strong and Dale join the Polaris to destroy it. Manning, left in command while the others sleep, recklessly increases speed to save the Earth and be a hero. Can the tubes handle the strain?
As the asteroid hurl towards Earth, Polaris is dead in space with a damaged tube. Capt. Strong takes Corbett and Manning outside the ship to replace the tube. But where is the runaway asteroid?
War games are supposed to be bloodless, but when a feud causes the Commander's flagship to crash, torpedoes are launched at Tom's spaceship and Roger Manning and another cadet are at each other's throats, casualties appear to be inevitable.
Space outlaws are preying on prospectors searching for uranium on remote asteroids. Tom and his fellow cadets are ordered to disguise themselves as miners in order to break-up the ruthless gang.
The captain of a tramp space freighter kidnaps Roger when his failure to maintain his vessel kills many of his crew. Tom and Astro infiltrate the ship to rescue Roger before the ship explodes due to its commander's negligence.
Twin threats imperil Tom and his men on a remote space station: a liquid compound is evaporating into the station's atmosphere sickening the crew while saboteurs plan to destroy the base with a nuclear time bomb.