The Boston Dynamics-built ATLAS is the rescue robot prototype that gets all the attention, but now NASA is getting in on the action, unveiling Valkyrie, a 6-foot 2-inch, 275-pound rescue robot. The 'bot, an entrant in the DARPA Robotics Challenge, a contest designed to find the life-saving robot of tomorrow, will soon undergo a test to see if it can perform tasks like climbing a ladder and using tools.