The New SR-72 Spy Plane Will Be the Real Speed Demon The SR-72 will be a mighty and speedy spy plane that will due justice to its amazing predecessor. Key point: As military and aviation technology continues to improve, the SR-71 may find a new lease on life through a sucessor. Here is how the SR-72 may well make history. Like a bolt out of the blue, Lockheed Martin’s renown Skunk Works publicly teased one of aviation’s great snark hunts—revealing plans for a successor to the SR-71, the legendary Mach-3 reconnaissance plane designed with slide rules and retired when the millennials were born.