The unsung computers that put the first American into space

50 years ago today, Alan Shepard, America's first astronaut, and the then-newly-formed National Aeronautics and Space Administration (or NASA to you and me) achieved an important milestone for the U.S. space program: America's first manned spaceflight.

The effort is often talked about in terms of the people involved, or the spacecraft that made it possible. Alan Shepard, for instance, is rightfully regarded as a national hero, and the humble Redstone rocket that carried him into sub-orbit is an iconic reminder of that first flight.

There's a crucial component that also played a massive role, however, a young technology at the time that rarely gets its due considering how important it was: the computer.

Start of The Space Race

To understand the importance of the computer to the fledgling space program, we need to set the scene a little bit: it's 1961, the Cold War, and the Space Race between America and Soviet Russia is about to kick off. The Soviet space program shocked the world with its launch of Sputnik 1 in 1957, which was the first man-made object to be placed in orbit. Prior to the Sputnik program, America believed itself to be the leader in rocket technology, and the scramble caused by this unforeseen development became known as the "Sputnik Crisis."

In 1958, the U.S. government quickly formed two new agencies: ARPA, the Advanced Research Projects Agency (now DARPA), to investigate space as a theater for military technology, and NASA, which was tasked with the same but for non-military applications.

America responded in 1958 with its own satellite, Explorer 1, but the next step was clear: manned spaceflight.


Sky's No Longer The Limit

Project Mercury, started in 1959, was created with the goal of realizing the first manned orbital spaceflight. From the beginning, NASA knew that the endeavor would require technology to be used in new and novel ways, and the agency planned for a real-time tracking network that would allow flight controllers to receive up-to-the-second updates on a rocket in flight.

This was vitally important as it took the guesswork out of a rocket launch. Controllers would be able to do more than sit back and hope everything went according to plan. Now, the plan was something that evolved every second — did a rocket mission need to abort mid-flight? Were there small adjustments during flight to be made? Were the crews waiting to recover the astronaut still in the right place?

With that in mind, NASA brought on now-defunct Western Electric — which, up until 1995, was responsible for the majority of AT&T's manufacturing and phone production — and the International Business Machines Corporation. You know: IBM.


Meet The Computers

Western Electric and IBM went about developing a worldwide network of remote tracking sites that would allow NASA to have eyes — whether they're looking through binoculars, or based on telemetry provided by radar installations — on its rockets at all time, from launch to landing.

At the heart of this system were three computers provided by IBM, including two of the company's transistorized 7090 machines, which had CPUs as large as desks and sold for millions each. One 7090 with all the fixin's took up an entire room. In terms of today's computing power, the 7090s had less going on in them than the smartphone in your pocket, yet they very clearly demonstrated the problem-solving power of computers. Two 7090s were installed at the Goddard Space Flight Center in Maryland, with a slower, vacuum-based IBM 709 running interference at a backup control center in Bermuda. All of it then plugged back in to the flight maps and displays at Cape Canaveral in Florida, transmitted at a rate of 2,400 bits per second (which, at the time, was quite the scorching speed).

This real-time network was the first of its kind. The trio of computers were not just there to crunch numbers, though. The output of the machines was what determined a Go or No-Go order — launch or abort. A mistake in computing could have meant a mistake that jeopardized Alan Shepard, his Freedom 7 capsule and America's dreams of manned spaceflight.


"We Were Never Nervous"

"I've been asked the question, 'Were we nervous about this,' and the truth is that we weren't. We were never nervous," IBM-alum Art Cohen told DVICE at the company's old headquarters in New York City.

Mr. Cohen, pictured above with his Goddard control center team, fourth from left, oversaw IBM's involvement in Project Mercury. In fact, he would stand at a console with two big colored buttons, one green and one red: Go or No-Go. For Cohen, the success of America's first manned spaceflight is also a victory for the fledgling computers involved — a victory that by and large goes unrecognized.

"The computer was the silent partner in all of this," Cohen continued. "Computing is the silent partner in a lot of stuff." Even today, computers remain our silent partner. I'm writing this right now on one, you're reading it from a computer — whether it's on a desk or fits in your pocket — and very nearly anyone who wants to get anything done across America, for business, art, pleasure and anything else, will use a computer to do it.

We can trust a computer now because we more or less know what it can do for us in basic terms. Art Cohen and his team in the Computation and Communications Control Center at Goddard were using computers that came from IBM's second generation of the technology. The IBM 709 in Bermuda was from IBM's first generation of computers, even.

How could he not be nervous? "From someone else's standpoint that might sound foolhardy, but we had a lot of experience," Cohen answered. "I think we had the best people at the time. And that counts. And not one flight was delayed because of a computer, and that was something to be proud of."


IBM 709 and All Its Tubes

A first generation IBM machine, the vacuum-tube-based 709 Data Processing System was released in August, 1958, though the computer was only available until the first half of 1960 when it was steadily replaced by more powerful transistorized machines (more on that when we look at the 7090). Vacuum tubes, while crucial to early computing and used in televisions, radar systems, telephones and more, were found to be less efficient, larger and more expensive than the transistors that followed. (Pictured above: a vacuum tube logic board used in IBM's 700 series.)

The 709 and the IBM computers that followed it were modular in much the same way as today's computers, save you'd be adding inter-connected units of magnetic tape drives (like our hard disk drives) and card readers (think optical drives such as a DVD reader), and these extra units would be the size of a chest of drawers or cabinet, not something measured in mere inches. The core of the 709 was the CPU and nerve center, but it needed additional equipment: punch card readers, printers, magnetic tape (high speed) and drum (high capacity) storage, and even external data synchronizers to help manage all these various input-output units.

It's important to understand that the computers of yesteryear didn't include the graphics user interfaces we have today with Windows, iOS and the like, or even software. It was all math enabled by operand addresses and what are called index registers, which manipulated data using various mathematical functions. Memory was arranged in 36-bit binary blocks, of which the 709 supported 32,768 words (six characters wide), allowing it to perform 42,000 instances of addition or subtraction, or 5,000 multiplies every second. These computations would then be translated by an assembly program, which could arrange the data and make it useful for applications related to physics or chemistry, or other computing-intensive applications such as weather forecasting. The 700 series was important as it was the first time IBM rolled out its Fortran programming language — which essentially made writing other programs easier.

In terms of Project Mercury, the 709 deployed by IBM was used at the Bermuda range station, where it calculated "normal orbital flight information in addition to its most important function — determining trajectory dynamics during the critical launch and early orbit phase." The 709 did this by pulling from local radar and telemetry sites, and was even responsible for the Go No-Go decision during space insertion by a spacecraft. In other words, the 709 was the Mercury Control Center's eyes while a vessel was performing orbital and sub-orbital positioning.

A detailed account of the IBM 709's capabilities and supporting devices can be found by clicking this link.


The Transistorized IBM 7090

The 7090 represented the future: the 7000 series of machines that would replace the older vacuum-tube-based 700 models. The 7000 series used transistors, and the 7090 itself "has computing speeds six times faster than those of its vacuum-tube predecessor, the IBM 709," according to IBM. Using transistors as semiconductors not only made machines more efficient, but reduced costs and allowed for smaller machines (not to mention smaller radios and calculators and other gadgetry).

The first 7090 was installed by IBM in December, 1959 — just a year after the 709 release — and the platform enjoyed great success in business and military applications, being used by the Air Force's Ballistic Missile Warning System and by American Airline's SABRE system, which handled passenger reservations and is still in use today — though not using 7090s. And, of course, by Project Mercury, as seen above in 1962.

In regards to Project Mercury, the duplexed 7090s had very specific and vital roles. The pair of 7090s at Goddard were essentially the brains, and were used to perform launch calculations, determine the trajectory and position of the craft, and predict where it will be based on the incoming telemetry data from all the sites. They were also the engine behind all the displays in the Mercury HQ at Cape Canaveral. Information flowed in to the Goddard duo through a network of thirty-two subchannels in what was called the Data Communications Channel, which enabled the real-time communication between Goddard, Bermuda and the Cape. The pair of 7090s would process all of the same information and spit it out on to monitors for the Goddard team to keep track of and watch for discrepancies. At all times, these computations were informing controllers whether or not the mission should continue.

A third 7090 at the Cape Canaveral Command Center performed an even more specialized role as the mission's Impact Predictor, or the IP 7090. The IP 7090 was tasked with constantly refining the trajectory of a launched spacecraft, which it fed back to Goddard at a rate of 1,000 bits per second. For the most part, the IP 7090 was helping process a lot of the raw data from telemetry sites to provide the Goddard duplex with refined trajectory information. In the event of a mission abort, however, the predictor would often take a back seat to raw data, which would then be shoveled directly to Goddard.

Find more information about the 7090 line at IBM by clicking this link, or Wikipedia actually has a pretty decent rundown comparing the 700 and 7000 series computers.


"Computing Will Lead The Way"

On May 5, 1961, Alan Shepard piloted Freedom 7, riding up into space atop a Redstone rocket. His journey saw him along a set ballistic trajectory and took all of 15 minutes. He splashed down safely in the water along the Atlantic Missile Range and was recovered in a neat 11 minutes — from splashdown to coming aboard — by the aircraft carrier USS Lake Champlain. All this would be after Soviet cosmonaut Yuri Gagarin successfully orbited the Earth in an automated craft (Shepard's had flight controls to make minor adjustments) on April 12, just under a month before.

This is the story that's usually told.

During this time, however, Art Cohen, his team and his computers were reducing the plethora of variables into raw mathematics. Did Freedom 7's separation from the Redstone go as planned? Was the path Alan Shepard piloted his capsule on going to put him down in the water, or crash him into land? Shepard's flight was so tidy because of the data generated by Cohen and his computers, and the well-informed decisions NASA flight controllers at Cape Canaveral (above) could make in turn.

"We were the funnel through which all the data came. We made sure it was synchronized, and all that data came through us," Cohen explained. "We got position data, velocity data, and a time stamp. And there was a lot of telemetry data. Our function was to track the capsule. That's essentially what we did."

"I look back on it as a fun time," Cohen said, minimizing his involvement and the enormity of the task that was presented to him. Despite having had a major role in getting an American up into space for the first time, for Cohen it was more about the part computers played and continue to play here on Earth.

"We need to perfect our planet. And that's where computing comes in. The way I see it, the sky's the limit. It's going to help all of mankind. It has to," Cohen said, adding, "Think of all the medical advances. Maybe computers can help improve yields [in food production]. Maybe poverty doesn't have to exist."

Cohen doesn't discount space, though: "In terms of space, I think it's important to understand about quarks and black holes and all these different things, but I think it's important to understand them to learn more about our Earth."

"Computing is going to lead the way," he concluded. "I really feel that."

Surprisingly — or unsurprisingly, considering how humble Cohen is about his involvement with Project Mercury — he seems more excited about where computers are taking us, citing the transforming role of social networks in countries such as Egypt and how many of today's tech giants, from Bill Gates to Mark Zuckerberg, were once computer-savvy kids who dropped out of school.

"That could have been me back then, you know?" Cohen, who now teaches math at Nassau Community College in Garden City, New York, says this with no damning caveat, no aside about how today's youth, in America especially, are often considered technologically spoiled or seen as clumsily navigating a high tech landscape for selfish gain. "I see you kids," Cohen said, "And I think we're going to be all right."

You can see Art Cohen talk more about his team, computers and Project Mercury in a video by IBM by clicking this link, and be sure to hit up our gallery down below for more information and images about the mission.

This post uses images and supplementary mission documents provided by IBM, and Art Cohen was gracious enough to give us an hour of his time.

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