Putting even something so unsophisticated as a brick into orbit would require the plotting of an exact trajectory handily done only by a computer. Sending the Mercury capsule aloft obviously requires a more refined aiming system, and its re-entry into the atmosphere demands a nicety of calculation measured in a fraction of a degree. The same is true for the Russian achievements in sending a space vehicle around the moon, and manned capsules in prolonged orbit. Such navigation can be planned and carried out only by the sophisticated mathematics of a computer. Dr. Wernher von Braun has said that any effective space-vehicle firing program would be impossible without computers and computing techniques.
Not long ago, the mariner could leisurely brace himself on the deck of his vessel and take a noon sight with his sextant. It mattered little if it took him some time to work out the computations; his ship traveled at only a few knots and in only two dimensions. Today the space capsule or missile moves as far in a single minute as a ship might in an entire day, and it moves not across the practically flat surface of the sea but through three-dimensional space in which that third degree of freedom is of vital importance. Not only must the navigation be done with fantastic precision, it must be done in “real time” to be of any value. This is true whether the mathematics is being done by a Mercury capsule or one of our antimissile missiles. Just as Richardson’s weather prediction three months after the fact was of little use, the trajectory of an invading missile will avail us nothing if it takes us thirty minutes to compute. The problem by then, for the survivors, will be one of fallout and not blast.
For this reason a computer is aboard practically every space vehicle that leaves the earth. The Atlas and Titan, the Minuteman and Polaris, all are controlled by tiny digital computers in their innards, supplemented by more complex machines on the ground. These ground computers calculate the trajectory, then monitor the missile to correct its course if necessary. Complex as these functions seem, they are childishly simple by comparison with the kind of calculations that are necessary for lunar or planetary flight.
A mathematician who knew his astronomy could work out the figures necessary to launch a space craft on its flight to Venus, but he would have to start some time before launching day. In fact, it would take forty generations of mathematicians to do the job. The trip itself would consume about four months. At the Jet Propulsion Laboratories of the California Institute of Technology, this 800-year project is planned and flown in thirty seconds by an IBM 7090 computer. For example, the computer tells us that if we had blasted off bright and early on August 17, 1962, we could make it to the Clouded Planet at 10:09 a.m., December 9. The curved trip through space would cover 32,687,000 miles.
The computer, then, not only can perform in real time but can even shrink time. The Venus trip is simulated daily at the Jet Propulsion Laboratories, and tapes stored in the computer cabinets also bear the names Moon, Mars, Saturn, Jupiter, and so on. When the day comes to make the actual voyage, the odds are good that because of what scientists have learned from the computer the trip will go as smoothly as all the simulations. Rather than the planetary voyages, which are still some time off, lunar soft landings will be among the first to demonstrate the accuracy of simulations now being made by General Dynamics, whose Atlas-Centaur will put the lunar rover Surveyor on the moon shortly. Apollo, the three-man lunar spaceship, won’t be far behind.
Not long ago a computer was put to work to see if it could pare down the costs of the Atlas and Thor rocket engines. We have to have such defensive weapons, but the cheaper we can make them the more we can afford. The economy program worked, reducing costs more than a third.
Summary
The computer is on the Washington payroll to stay, and it may well move up the hierarchical ladder there. It was not a comedian but an M.I.T. professor who recently suggested that the computer will replace the bureaucrat. Contending that the computer is inherently more flexible than the bureaucrat, Professor John McCarthy told an Institute of Radio Engineers meeting that the machines will not regiment us. “On the contrary, I think we can expect a great deal more politeness from machines than we have gotten from humans,” he said. His views were debated by other panelists, but the gauntlet seems to have been flung. With a party affiliation, the computer may well run for president someday!
Lichty, © Field Enterprises, Inc.
“It IS human, men!... Besides solving our problems of global strategy, it’s also beginning to jot down its memoirs!”