The underwater transformer: Ex-NASA engineers built a robot sub that transforms into a skilled humanoid

I'm drifting weightlessly, in a silence broken only by my own breathing and the occasional update from Mission Control in my headset. But this isn't the dark void of space. I'm in Houston, scuba diving in a massive swimming pool that NASA uses to train astronauts for zero-gravity environments. And though it's a thrill to watch the space-suited figures at work, I didn't come to see them. I'm here for a peek at Aquanaut, the bright orange robot that we're sharing the pool with.