When we last saw Boston Dynamics' AlphaDog (aka LS3), it was strutting through outdoor trials with the subtlety of a nuclear missile: for all that noise, it might as well have been holding a "shoot here please" sign broadcasting American soldiers' positions to everyone in the forest. Several months later, the company is showing both DARPA and the Marine Corps a refined version of its load-carrying robot that has clearly been through a few rounds of obedience school. While we still wouldn't call the four-legged hauler stealthy, it's quiet enough to avoid the role of bullet magnet and lets nearby troops chat at reasonable volumes. And yes, there's new tricks as well. AlphaDog can speed up its travel over difficult surfaces and move at up to a 5MPH jog, all while it's following a human squad. DARPA and the Marines recently began testing and improving the robot over a two-year period that should culminate in an Advanced Warfighting Experiment with the Marines to test viability under stress. If AlphaDog passes that bar, there's a good chance many on-foot soldiers will have a mechanical companion -- and quite a weight lifted off of their shoulders.