The robot, nicknamed ABE, was one of the first successful submersible vehicles that could operate both unmanned and untethered to surface ships. Officials said it was lost Friday during a research expedition off the coast of Chile.
Scientists said the 15-year-old vessel was launched late Thursday night and had reached the seafloor to begin its 222nd research dive when, during the early hours of Friday, all contact with the vessel abruptly ceased and efforts to re-establish contact failed.
The vehicle was designed, built and operated by Woods Hole scientists and engineers who theorize ABE might have suffered a catastrophic implosion of one of the glass spheres used to keep it buoyant. Officials said an implosion, under pressure equivalent to more than two tons per square inch at a depth of 1.86 miles would have caused all of ABE's other spheres to implode, destroying on-board systems used to communicate with the surface ship and return ABE to the surface.
The scientists said the loss was not related to ongoing earthquake activity off Chile.