"Bully for you, Mr. Danley! Now see if you can put into action that which you have so succinctly put into words. Come back to the boat. Gently the first time. We'll have plenty of practice, so that you can get the feel of the muscle pull that will give you a maximum of velocity with a minimum of impact at this end. Gently, now." * * * * * Still later: "Judgment, Mr. Danley!" St. Simon cautioned. "You have to use judgment! A space boat is not an automobile. There is no friction out here to slow it to a stop. Your accelerator is just exactly that--an accelerator. Taking your foot off it won't slow you down a bit; you've got to use your reverse." Peter Danley was at the controls of the boat. There were tiny beads of perspiration on his forehead. Over a kilometer away was a good-sized hunk of rock; his instructors wouldn't let him get any closer. They wanted to be sure that they could take over before the boat struck the rock, just in case Danley should freeze to the accelerator a little too long. He wasn't used to this sort of thing. He was used to a taped acceleration-deceleration program which lifted a big ship, aimed it, and went through the trip all automatically. All he had ever had to do was drop it the last few hundred feet to a landing field. "Keep your eyes moving," St. Simon said. "Your radar can give you data that you need, just remember that it can't think for you." _Your right foot controls your forward acceleration._ _Your left foot controls your reverse acceleration._ _They can't be pushed down together; when one goes down, the other goes up. Balance one against the other._ _Turning your wheel controls the roll of the boat._ _Pulling your wheel toward you, or pushing it away, controls the pitch._ _Shifting the wheel left, or right, controls the yaw._ The instructions had been pounded into his head until each one seemed to ring like a separate little bell. The problem was coordinating his body to act on those instructions. One of the radar dials told him how far he was from the rock. Another told him his radial velocity relative to it. A third told him his angular velocity. "Come to a dead stop exactly one thousand meters from the surface, Mr. Danley," St. Simon ordered. Danley worked the controls until both his velocity meters read zero, and the distance meter read exactly one kilometer. "Very good, Mr. Danley. Now assume that the surface of your rock is at nine hundred ninety-five meters. Bring your boat to a dead stop exactly fifty centimeters from that surface." Danley worked the controls again. He grinned with satisfaction when the distance meter showed nine nine five point five on the nose. Captain St. Simon sighed deeply. "Mr. Danley, do you feel a little shaken up? Banged around a little? Do you feel as though you'd just gotten a bone-rattling shock?" "Uh ... no."