He was one of the first successful, unmanned, free-swimming ocean robots. But now, the 15-year-old autonomous benthic explorer - beloved ABE to those that designed, built and operated him at the Woods Hole Oceanographic Institution - is gone, lost off the coast of Chile in the early hours last Friday.
On its 222nd dive, researchers on the vessel Melville lost all contact with the autonomous vehicle. Best guess what happened? A catastrophic implosion of one of the glass spheres used to keep ABE buoyant. If that happened, the pressure at 1.86 miles down - two tons per square inch - would have caused all of ABE's other spheres to implode, leaving it unable to surface and destined to remain forever at sea.