changed his status from passenger to pilot. He had little enough time to work. He could not follow the missile down into the atmosphere; his ship would burn up. He must begin his pull-out at not fewer than two hundred miles altitude. That left him one hundred eighty-three seconds in which to locate and destroy the warhead. The screen in the center of his instrument panel could show a composite image of the space in front of his ship, based on data from a number of sensing elements and detectors. He switched on an infrared scanner. A collection of spots appeared on the screen, each spot indicating by its color the temperature of the object it represented. The infrared detector gave him no range information, of course. But if the autopilot had done its job well, the nearest fragment would be about ten miles away. Thus even if he set off the enemy warhead, he would be safe. At that range, the ship would not suffer any structural damage from the heat, and he could be down on the ground and in a hospital before any radiation effects could become serious.

He reflected quickly on the possible temperature range of the missile components. The missile had been launched from Central Asia, at night, in January. There was no reason to suppose that the warhead had been temperature-controlled during the pre-launch countdown. Thus it probably was at the ambient temperature of the launch site. If it had been fired in the open, that might be as low as minus 70° F. Had it been fired from a shelter, that might be as high as 70° F. To leave a safety margin, he decided to reject only those objects outside the range plus or minus 100° F. There were two fragments at 500° F. He rejected these as probably fragments of the engine. Six more exhibited a temperature of near minus 320° F. These probably came from the liquid oxygen tanks. They could be rejected. That eliminated eight of the objects on the screen. He had nineteen to go. It would be a lot slower for the rest, too.He switched on a radar transmitter. The screen blanked out almost completely. The missile had included a micro-wave transmitter, to act as a jammer. It must have been triggered on by his approach. It obviously hadn't been operating while the ship was maneuvering into position. Had it been transmitting then, the autopilot would simply have homed on it. He switched the radar to a different frequency. That didn't work. The screen was still blank, indicating that the jammer was sweeping in frequency. He next tried to synchronize his radar pulses with the jammer, in order to be looking when it was quiet. The enemy, anticipating him, had given the jammer a variable pulse repetition rate. He switched off the transmitter, and scanned the radar antenna manually. He 

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