Genius_ The Life and Science of Richard Feynman - James Gleick [249]
A Disaster of Technology
In 1958, a hasty four months after Sputnik, Americans entered what was called the space race by sending into orbit the first of a series of Explorer satellites from Cape Canaveral, Florida. Explorer I weighed as much as a fully packed overnight bag. It was hurled skyward on January 31 by a four-stage Jupiter-C rocket—more reliable than the navy’s Vanguard rockets, which had been exploding at liftoff. It sent back radio signals much like Sputnik’s.
Explorer II, bearing a cosmic-ray detector that pushed its weight up to thirty-two pounds, soared skyward five weeks later and disappeared into the clouds. An army team watched under the guidance of Wernher von Braun, resilient veteran of the Nazi rocket program at Peenemünde. They listened to the fading rumble of the rocket and the rising beep of the radio signal transmitted to their squawk box. All seemed well. A half hour after the launch, they held a confident news briefing.
Across the continent, where the Jet Propulsion Laboratory in Pasadena served as the army’s main collaborator in rocket research, a team was struggling with the task of tracking the satellite’s course. They used a room-size IBM 704 digital computer. It was temperamental. They entered the primitively sparse data available for tracking the metal can that the army’s rocket had hurled forward: the frequency of the radio signal, changing Doppler-fashion as the velocity in the line of flight changed; the time of disappearance from the observers at Cape Canaveral; observations from other tracking stations. The JPL team had learned that small variations in the computer’s input caused enormous variations in its output. Albert Hibbs, the laboratory’s young research chief, had complained about this difficulty to his former Caltech thesis adviser: Feynman.
Feynman bet that he could outcompute the computer, if fed the same data at the same rate. So when Explorer II lifted off the pad at 1:28 P.M., he sat in a JPL conference room, surrounded by staff members rapidly sorting the data for the computer. At one point Caltech’s president, Lee DuBridge, entered the room and was startled to see Feynman—who snapped, Go away, I’m busy. After a half hour Feynman rose to say he was finished: according to his calculations the rocket had plunged into the Atlantic Ocean. He left for a weekend in Las Vegas as the trackers kept trying to coax an unambiguous answer from their computer. Tracking stations at Antigua and Inyokern, California, persuaded themselves that they had picked an orbiting satellite out of the background noise, and “moonwatch” teams in Florida spent the night watching the skies. But Feynman was right. The army finally announced at 5 o’clock the next afternoon that Explorer II had failed to reach orbit.
The space shuttle Challenger rose from its launching scaffold into a cloudless sky twenty-eight years later, on January 28, 1986. A half second after liftoff, a puff of dark smoke, invisible to human eyes, spurted from the side of one of the shuttle’s two solid-fuel rockets. The launch had been postponed four times. Inside the cabin, as always, the many-gravity acceleration pressed the crew against their seats: the commander, Francis Scobee; the pilot, Michael Smith; the mission specialists, Ellison Onizuka, Judith Resnick, and Ronald McNair; an engineer from the Hughes Aircraft Company, Gregory Jarvis; and a New England schoolteacher, Christa McAuliffe, who had been chosen as “Teacher in Space,” the winner of a NASA public-relations program meant to encourage the interest of children and also congressmen. The cargo bay—large enough to have carried the 1950s Jupiter-C rocket—held a pair of satellites, a fluid-dynamics experiment, and radiation-monitoring equipment. Ice had built up overnight, and new delays had been ordered while an ice inspection