"Sorry, Commodore. I didn't mean to be scornful."
"Well, then, you'd better set up your space grid in the coordinate tank and we'll start combing it cube by cube."
"Correct," said Toby Manning.
The "tank" was not really a tank. It was a stereo projection against a flat glass wall at one end of the big Information Center Room below the bridge section of the flagship. Wilson went there some time later to watch the bustle as the tank was set up to cover the segment of space they intended to comb.
Even looking at the thing required some training. The plotters and watchers wore polaroid glasses to provide the stereo effect. Through the special glasses, the tank looked like a small scale model of this section of the sky. Castor and Pollux and other nearby stars were no longer pinpoints on a flat black surface, but tiny points of light that seemed to hang in space, some in front of and some behind the position of the screen itself.
Behind the glass screen, a technician was carefully laying a curve down on a drawing table with a pantagraph instrument. As he moved the pencil point along the curve, a thin green line appeared in stereo, starting close by and abruptly, and leading towards the dot labeled Castor.
The loud-speaker said, "This green line is the computed course of Spaceflight Seventy-nine."
A red knot was placed on the line.
"This is the approximate point of explosion."