_RETROSPECT Project Orion: Saturn by 1970 _{By George Dyson}

What if the 1950s had just kept on going?

Fifty years ago tail fins, not seat belts, launched, General Atomic issued T. B. Taylor’s Note were standard equipment on American cars. Russia on the Possibility of Nuclear Propulsion of a Very Large was ahead in space, but America was ahead on the Vehicle at Greater than Earth Escape Velocities. road. Sputnik I, weighing 184 pounds, was launched His proposal, submitted to ARPA in early 1958, on Oct. 4, 1957, and circled the Earth every 90 envisioned a 4,000-ton vehicle, carrying 2,600 minutes for the next three months. Sputnik II, weigh- 5-kiloton bombs. ARPA wrote a check for $999,750 ing 1, 120 pounds, followed on Nov. 3 and included to start things off. Suggested missions ranged from

Laika, the pioneer of spacefaring dogs. Earth’s third the ability to deliver “a hydrogen warhead so large artificial satellite was launched by a 32-ton Jupiter-C that it would devastate a country one-third the rocket built by the Chrysler Corporation, on Jan. 31, size of the United States” to a grand tour of the

1958. Explorer I weighed 31 pounds. solar system that Orion’s chief scientists envisioned

The race for space had begun. In Washington, as an extension of Darwin’s voyage of the Beagle:

D.C., the Advanced Research Projects Agency (now a four-year expedition to the moons of Saturn,

DARPA) was given a small office in the Pentagon including a two-year stay on Mars. and assigned the task of catching up. NASA would not exist until July of 1958. All three armed services had competing designs on space. “If it flies, that’s our department,” claimed the Air Force. “But they’re called spaceships,” replied the Navy. “OK, but the Moon is high ground,” answered the Army, who had already enlisted rocket pioneer Wernher von Braun.

ARPA’s mission was to consider all alternatives, however far-fetched. One of the alternatives, code-named Project Orion, was an interplanetary spaceship powered by nuclear bombs. Orion was the offspring of an idea first proposed, as an unmanned vehicle, by Los Alamos mathematician Stanislaw Ulam shortly after the Trinity atomic bomb test at Alamogordo, N.M., on July 16, 1945. It was typical of Ulam to be thinking about using bombs to deliver missiles, while everyone else was thinking about using missiles to deliver bombs.

With Sputnik circling overhead, Los Alamos bomb designer Theodore B. Taylor (see MAKE, Volume 07, page 188), who had recently moved to the General Atomic Division of General Dynamics, decided Ulam’s deserved another shot. “I was up all night and then I got alarmed that things were getting big,” he recalls. “Energy divided by volume is giving pressure, so the pressures were out of sight, unless it was very big. It got easier as it got bigger.”

According to Taylor, it was Charles Loomis, a former Los Alamos colleague working in the adjacent office, who said, “Well, think big! If it isn’t big, it’s the wrong concept.” Taylor’s perspective shifted. On Nov. 3, 1957, the day that Sputnik II (with Laika aboard) was

Could you blow something up

without blowing it up? The answer

appeared to be yes.

“Saturn by 1970,” projected the physicists. “ Whoever controls Orion will control the world,” claimed General Thomas Power, commander in chief of the Strategic Air Command. An Air Force review of the project concluded: “The uses for Orion appear as limitless as space itself.”

At the center of General Atomic’s new 300-acre campus in La Jolla, Calif., near Torrey Pines, was a circular technical library, two stories high and 135 feet in diameter — exactly the diameter of the 4,000-ton Orion design. The library provided a sense of scale. Ted Taylor would point to a car or a delivery truck, the size of existing space vehicles, and say, “This is the one for looking through the keyhole.” Then he would point to the library and say, “And this is the one for opening the door.”

Orion was to be a one-cylinder external combustion engine: a single piston reciprocating within the combustion chamber of empty space. The ship, egg-shaped and the height of a 20-story building, is the piston, armored by a 1,000-ton pusher plate attached by shock-absorbing legs. The first 200 explosions, fired at half-second intervals with a total yield equivalent to some 100,000 tons of TNT, would lift the ship from sea level to 125,000 feet. Six hundred more explosions, gradually increasing

176 Make: Volume 12