Bill Stone's Bathtub Sub

Back when I was having swimming lessons at school, one of the tasks we had to complete in order to get a certificate was collecting a rubber brick from the deep-end of the pool.  I'm not sure exactly what this was designed to prepare us for – working for a miserly and slippery-fingered brick layer as he constructs a river-spanning bridge, perhaps – but I now know that I should have called upon the services of DepthX, Bill Stone's awesome autonomous underwater robot.

Designed to eventually exploring the subterraneous lakes of Europa, one of Jupiter's moons, DepthX was recently put through its paces at an underwater cave in Mexico.  Diving to 300 feet and recording photos and video, the robot built a 3D map of the area and moved about of its own accord, collecting samples and even spotting a rare purple scorpion.

With a $5million NASA grant and his own reputation riding on the success of the robot, Stone will be a very relieved man with this first mission under his – and DepthX's – belt.  Later this year it will attempt to explore Zacaton, the world's deepest sinkhole, sinking more than 1000 feet.

DepthX: Mission 1 Accomplished [Popular Science]