A deep sea
drilling ship built in 1968 for
ocean floor studies by the
Deep Sea Drilling Programme. The Glomar Challenger was designed for computer controlled
navigation, using bow and stern thrusters and acoustic beacons on the sea floor. The
propulsion system enabled the ship to remain in a relatively stationary position over a drill site in water too deep to
anchor.
Acoustic guidance systems allowed for the easy replacement of
drill bits and exact reentry of bore holes in 6000 meters (20,000 ft) deep water.
Before its retirement in 1983, the Glomar Challenger had removed 96 kilometers (60 miles) of deep sea cores and the
studies of these cores alllowed for definite proof of
seafloor spreading and the discovery that no ocean
crust is older than approximately 180 million years.