Jet Powers #4

A space-bound ship is halted by magnetic grapples and invaded by alien forces who overcome the crew with weird weapons. Jet Powers hides and escapes in a spacesuit, preferring to freeze in space rather than be captured by the creatures. He encounters Benton Thorpe, the greatest scientist in the solar system, who reveals the aliens came seeking to capture humans for study and have taken Thorpe's crew. Thorpe's vessel, the Starmist, carries a ray-generator powered by magnetic relays that proves effective against the Martians, though it doesn't harm Jet. As the aliens attack the planet they have discovered—long thought lost to catastrophe—Jet must defend it from their assault.