It settles into the Atlantic with a small splash. The waves are starting to build. A ticking clock Down, down, down. So unimaginably far down. I stare at the seabed.
Someone says it looks like the moon.
Ron and Mark begin testing Magellan's sonar, needed to help us hone in on man-made objects. The navigators have tried to set us down to within 100 meters of the target. After that, Magellan has to get there on its own. Ron grips the control, flying the robot a few meters off the ocean's bottom. Mark searches for a distinctive sonar ping that will let him know the equipment is working properly.