The Mission Control Room had an immense map of the world spread across its 140 feet breadth. It showed the actual and projected trajectories of the Shuttle. Along both sides of the map were several large rear projection video screens. They displayed the various camera angles of the launch pad, the interior of the Shuttle's cargo hold, the cockpit itself and an assortment of other shots that the scientists deemed important to the success of each flight. T-MINUS 90 SECONDS AND COUNTING "At the T-Minus one minute mark, the ground launch sequencer will verify that the main shuttle engines are ready to start." T-MINUS 80 SECONDS AND COUNTING "Liquid hydrogen tanks now reported at flight pressure." The data monitors scrolled charts and numbers. The computers spewed out their data, updating it every few seconds as the screens flickered with the changing information. T-MINUS 70 SECONDS AND COUNTING The Voice of Mission Control continued its monotone countdown. Every airline passenger is familiar with the neo-Texas twang that conveys sublime confidence, even in the tensest of situations. The Count-down monitor above the global map decremented its numbers by the hundredths of seconds, impossible for a human to read but terribly inaccurate by computer standards. "Coming up on T-Minus one minute and counting." T-MINUS 60 SECONDS. "Pressure systems now armed, lift off order will be released at T-Minus 16 seconds." The voice traffic became chaotic. Hundreds of voices give their consent that their particular areas of responsibility are ship- shape. The word nominal sounds to laymen watching the world over as a classic understatement. If things are great, then say 'Fuel is Great!' NASA prefers the word Nominal to indicate that sys- tems are performing as the design engineers predicted in their simulation models. T-MINUS 50 SECONDS AND COUNTING. The hoses that connect the Shuttle to the Launch Pad began to fall away. Whirls of steam and smoke appeared around portions of the boosters. The tension was high. 45 seconds to go. "SRB flight instrumentation recorders now going to record." Eyes riveted to computer screens. It takes hundreds of computers to make a successful launch. Only the mission generalists watch over the big picture; the screens across the front of the behe- moth 80 foot high room. T-MINUS 40 SECONDS AND COUNTING "External tank heaters now turned off in preparation for launch." Screens danced while minds focused on their jobs. It wasn't until there were only 34 seconds left on the count down clock that anyone noticed. The main systems display monitor, the one that contained the sum of all other systems information displayed a message never seen before by anyone at NASA. @COMPMEMO "CHRISTA MCAULIFFE AND THE CHALLENGER WELCOME THE CREW OF THE SPACE SHUTTLE COLUMBIA."