first image (entitled 'Introduction and Background') to the center screen with another touch of the keyboard.
'Yesterday morning,' he began, 'a demonstration test for the new Panther missile was conducted over the North Atlantic. The missile was fired at 0700 from an airplane at eighty thousand feet off the coast of Labrador. It was aimed at a target near the Bahamas, one of our old aircraft carriers. After flying a normal ballistic trajectory into the region where the ship was located, the Panther was supposed to activate its terminal guidance that uses the Advanced Pattern Recognition System or APRS. The missile should then have found the aircraft carrier and, using the reaction control jets as its primary control authority, made whatever vernier corrections were necessary to impact the old carrier on the main deck.'
Todd pushed a key on the podium and a line drawing map of the American east coast, including the area from Labrador through Cuba, appeared on the left screen. 'The missile was a final test version,' he continued, 'in the exact configuration of the production flight vehicle, except for the command test set and the warhead. This was to be the longest test flight yet conducted and was designed to demonstrate thoroughly the new 4.2 version of the software that was recently installed in the APRS. So of course the missile was not armed.'
The lieutenant picked up a light pen from the podium and marked on the small monitor in front of him. His markings were immediately translated to the larger screen behind him so that everyone could easily follow his discussion. 'On the screen you all can see the predicted versus actual overflight path of the bird yesterday. Here, roughly ten miles east of Cape Canaveral on what appeared to be a nominal flight, the sequencer turned on the cameras. After a couple of hundred calibration images, sort of a self-test of the APRS, the terminal guidance algorithms were activated as scheduled. As far as we can tell from the realtime telemetry, nothing strange had occurred until this time.'
The right screen now showed a detailed map of south Florida and the Keys that included the target in the Bahamas. The maps on the two flanking screens remained in view during the rest of his presentation but Lieutenant Todd constantly changed the word charts in the middle to keep up with the discussion. 'The a priori location of the target, which was where the cameras should first have looked for the aircraft carrier, was here at Eleuthera, in the Bahamas. The search algorithm should have fanned out in a circle from there and, if it had operated properly, found the target in about fifteen seconds. This (Todd pointed toward a dotted line on the more detailed map) should have been the impact trajectory.
'However,' Todd continued dramatically, 'based on the telemetry data that we have analyzed to date, it appears that the missile veered sharply westward, toward the coast of Florida, soon after the terminal guidance system was activated. We have only been able to reconstruct its path up to this point, where it was about three miles west of Miami Beach at an altitude of ten thousand feet. After that the telemetry becomes intermittent and erratic. But we do know that all the terminal guidance engines were on at the time we lost complete data. Projecting the total control authority for the missile, the area highlighted here, covering the Everglades, the Keys, and even as far south as Cuba, represents where the bird might have landed.'
Lieutenant Todd paused for a second and Commander Winters, who had been writing down major points in a small notebook during the presentation, immediately jumped in and started taking charge of the meeting. 'A couple of questions, Lieutenant, before we proceed,' Winters began in a businesslike manner with an obvious overtone of authority. 'First, why was the missile not destroyed soon after it veered off course?'
'We're not exactly certain, Commander. The command test set and the small ordnance had been installed, of course, specifically for that purpose. The change in the motion of the vehicle was so sudden and so unexpected that we reacted a little slowly at the beginning. By the time we sent the command, it's possible that we were out of range. All we know is that we never saw an explosion of any kind. We can only assume — '
'We'll come back to this operational error later,' Winters interrupted him again. Todd blanched at the word 'error' and fidgeted