Source: Fast Company, Jun 2019
The computer that flew the astronauts to the Moon—the Apollo guidance computer—was a marvel of the 1960s: small, fast, nimble, and designed for the people who were using it, astronauts flying spaceships.
It also represented a huge leap for NASA. The risk was in the cutting-edge technology that MIT used to squeeze as much power and speed into the computer’s slim, briefcase-sized case, one of the boldest and riskiest bets of the whole Moon mission, and one that few knew about or appreciated at the time.
The MIT Instrumentation Lab tried to design the Apollo computer using transistors, which in the early 1960s were well-settled technology—reliable, understandable, relatively inexpensive. But 15 months into the design effort, it became clear that transistors alone couldn’t give the astronauts the computing power they needed to fly to the Moon. In November 1962, MIT’s engineers got NASA’s permission to use a very new technology: integrated circuits.
As part of its early evaluation, MIT bought 64 integrated circuits from Texas Instruments. The price was $1,000 each, or $9,000 apiece in 2019 dollars. Each had six transistors.
But integrated circuits would change what it was possible for the Apollo computer to do. They would increase its speed by 2.5 times while allowing a reduction in space of 40% (the computer didn’t get smaller; it just got packed with more capacity).
The Apollo computers were the most sophisticated general-purpose computers of their moment. They took in data from dozens of sensors, from radar, directly from Mission Control. They kept the spaceships oriented and on course. They were, in fact, capable of flying the whole mission on autopilot, while also telling the astronauts what was going on in real time.
MIT did two things to solve the problems of those first integrated circuits. Working with early chip companies—Fairchild Semiconductor, Texas Instruments, Philco—it drove the manufacturing quality of computer chips up by a factor of 1,000. MIT had a battery of a dozen acceptance tests for the computer chips it bought, and if even one chip in a lot of 1,000 failed one test, MIT packed up the whole lot and sent it back.
And MIT, on behalf of NASA, bought so many of the early chips that it drove the price down dramatically: from $1,000 a chip in that first order to $15 a chip in 1963, when MIT was ordering lots of 3,000. By 1969, those basic chips cost $1.58 each, except they had significantly more capability, and a lot more reliability, than the 1963 version.
MIT and NASA were able to do all that because for year after year, Apollo was the No. 1 customer for computer chips in the world.
- In 1962, the U.S. government bought 100% of integrated circuit production.
- In 1963, the U.S. government bought 85%.
- In 1964, 85%.
- In 1965, 72%.
Even as the share dropped, total purchasing soared. The 1965 volume was 20 times what it had been just three years earlier.
Inside the government, there was only NASA using the chips, and the Air Force’s Minuteman missile, a relatively small project compared with the Apollo computers.
Without knowing it, the world was witnessing the birth of “Moore’s Law,” the driving idea of the computer world that the capability of computer chips would double every two years, even as the cost came down.
In fact, Fairchild Semiconductor’s Gordon Moore wrote the paper outlining Moore’s Law in 1965, when NASA had been the No. 1 buyer of computer chips in the world for four years, and the only user of integrated circuits that Moore cites by name in that paper is “Apollo, for manned Moon flight.” Moore would go on to cofound and lead Intel, and help drive the digital revolution into all elements of society.
What was Moore doing when he conceived of Moore’s Law? He was director of research and development. Fairchild’s most significant customer: MIT’s Apollo computer.
It’s a part of the history of modern computing that Silicon Valley manages to skip over most of the time, but MIT, NASA, and the race to the Moon laid the very foundation of the digital revolution, of the world we all live in.