Not Just Fly Boys Pilots in Space

For pilots, the systems men could represent a threat they had engineered a fleet of air force weapons that had no pilots at all and their abstract, analytical approach to engineering could seem to crowd out the ''human factor.'' These issues came to the fore as the test pilots began to contemplate spaceflight. As one flight test engineer remembered this period ''The 'head shrinkers' and the 'spasmatologists' had decided that man had reached the limits of his capabilities. There followed the...

Change in Culture

For the first few years of the Apollo program, IL engineers defined tasks, built prototypes, conducted experiments, and did much of the creative, exciting part of flying to the moon. In the middle of 1966, however, everything changed. At the end of the Gemini program, Lickly recalled, ''NASA descended on us.'' ''We awoke several years later realizing we had a big programming problem and now we needed a new organization,'' Martin recalled. ''Instead of having 30 people, we needed 200 people .we...

Going to Mars on Paper

Not all of the IL's engineers were absorbed in Polaris. After Sputnik, some sought to expand their horizons beyond earthbound missiles. Hal Laning, a mathematician and control engineer, had been at the IL since 1947, and was head of the small but crucial mathematics group. Laning recognized the intrigue and potential of the computer when he worked on Whirlwind, MIT's first computer, specially built for research in real-time control systems. He wrote a program called George, a small compiler for...

Hardware Failure and Software

Before his lunar landing flight, Jim Lovell said that he planned to land the LM in fully automatic mode. He never got a chance to try. The Apollo 13 story has become among the best-known aspects of the program, thanks to a number of books and a popular movie. Of course, that flight made no attempt at a lunar landing, so it will not be part of our analysis here. The crises during that mission generated plenty of interesting human-machine interactions, however, and the guidance system proved both...

Go for Powered Descent

Houston time. Less than two hours before, the LM had separated from the command and service module as the two flew in similar, safe orbits around the moon, preparing for the critical descent. Then the LM initiated its DOI burn, for ''descent orbit insertion'' around the far side of the moon, to bring Neil Armstrong and Buzz Aldrin down from a circular sixty-mile orbit to an elliptical one, sixty by ten miles. The crew carefully monitored the burn ready to cut...

Vision Skill and Automation

Despite the differences between the landings, all had one thing in common the commander did not allow the computer to land in automatic mode and instead operated the attitude ''manually'' in P66 (table 10.1). David Scott proved most reflexive about P66 ATT HOLD takeover altitude for six flights (compiled by the author from Apollo mission transcripts). his use of the automation, perhaps because of his education at MIT and his comfort with automatic controls. He described a single, integrated...

Automation in the Gemini Program

Less heralded than the human controls but equally important for the technical learning of spaceflight and its implications for Apollo was a new type of human-machine interaction, subtly importing the chauffeurs versus airmen dichotomy into the orbital realm. Most of Gemini's rendezvous and reentries relied on programs running on a digital computer. Intuitive piloting alone proved inadequate for rendezvous. Following Grissom and Young's successful demonstration of manual maneuvering on Gemini...

Building Programs

For about four years, the programming effort trundled along at a comparatively leisurely rate while the hardware design proceeded apace. No more than a hundred people worked on software until mid-1965, when the hardware effort peaked with more than six hundred people. Once the hardware design was completed, however, the manpower began to decline, and by the end of 1966 there were more people assigned to the software effort (about two hundred and fifty), which peaked at more than four hundred in...

Transistors to Chips

As often happens with a large project lasting several years, especially an electronic one, the basic technology for the Apollo computer was hardly static. Transistors, invented in 1948, had become commercially available and accepted in the 1950s, especially for military equipment. Integrated circuits (ICs) could put several transistors on a single semiconductor chip, doubling or tripling the package density. IL electronics guru Eldon Hall had incorporated an early IC into the Polaris Mark II...

Display and Keyboard

''How do you take a pilot, put him in a space ship, and have him talk to a computer '' astronaut David Scott succinctly put the question facing the IL. Nevins and his team embodied their philosophy in the interface to the Apollo computer. They developed a ''display and keyboard'' unit, abbreviated DSKY (pronounced ''dis-key''). Somewhat akin to an early calculator display, the DSKY had a numeric keyboard with plus and minus keys, and seven additional function keys like ENTER, CLEAR, and KEY...

High Gate 9000 Feet

At first glance, the lunar landing trajectory seems purely an engineering design, almost a high school physics problem employing the time-honored principles of Newtonian mechanics. Indeed, were the system totally automated, the LM would continue along a flat, fairly horizontal path, only orienting itself vertically as it neared the ground. But at about 9,000 feet the LM reached an imaginary point called the ''high gate,'' a term derived from aviation denoting the beginning of an approach to an...

The Command Center

With the momentum from Kennedy's speech, their head start, and the enthusiasm of an exciting project, NASA and the IL refined an initial statement of work, laying out their vision for the Apollo guidance system. Written during the early Mercury flights in August 1961, the statement built on and refined the Mercury approach toward automation and the pilots' roles. Again, in keeping with the IL engineering culture, they stipulated that navigation be autonomous, that ''the primary command and...

Reliability or Repair The Apollo Computer

If I wanted to write a philosophical novel about Apollo and say where did this technological capability come from And what was it You'd have to go back to these two things you developed a group of men and an approach, a systems approach if you will, that let you undertake high-speed flying, you developed a systems approach that lets you undertake risky missions and be able to call them ethical. That system plus the digital computer that's the Apollo mission. George Rathert, NASA Control...

Mission Planning

The LM seemed to work in space, but how to make it gently land on the lunar surface Early on, Space Task Group member Donald Cheatham laid out the basic ideas for landing. Cheatham believed that the landing phase should take advantage of the crew's judgment, especially in the final moments of selecting a specific landing spot. For him, the problem came under the old rubric of ''handling qualities,'' although with few parallels in traditional, atmospheric flight. Cheatham set up a series of...

The Langley Group

In 1958 NASA put together an upstart team at its Langley Research Center called the Space Task Group (STG) under the leadership of Robert Gilruth, the pioneer of flying qualities research. Gilruth assembled twenty-five young Langley engineers willing to stake their careers on a risky endeavor.21 They focused on the capsule itself the Redstone rocket to loft it into space would be supplied by von Braun's group in Alabama. The Germans had spent more than twenty years building and flying rockets...

Controlling a Spaceship

Any story of a lunar landing must of course begin with the LM, among the strangest and most interesting craft to fly in the twentieth century (figure 8.1). ''Fly'' in this case is a loose term the LM never had to work within the earth's atmosphere, to fly in air. The command module carried a sleek, aerodynamic shape around the moon because it had to push through the air on the way up and burn through it on the way down. Not so with the LM, whose odd and seemingly random protrusions kept it LM...

Test Pilots and Survival

The Society of Experimental Test Pilots (SETP) held its first annual awards banquet on October 4, 1957. These men sat at the top of the piloting profession, crossing the border between engineering and flying skills. They had been rocketed to fame by Chuck Yeager's epochal supersonic flight nine years before. The atmosphere in the banquet hall was electric as the group celebrated its new society epitomizing professional maturity. Six hundred and fifty people attended, many of them making the...

Sheas Systems Approach

As the AGC hardware evolved, so did NASA's management of the project. In early 1963, Brainerd Holmes, who headed Apollo at NASA headquarters, left the agency after a disagreement with Webb. That July, Webb consolidated management at the agency and hired a new man to bring coherence and control to the program. George Mueller came to NASA from air force systems engineering contractor TRW, taking over Holmes's job as NASA deputy associate administrator for manned spaceflight. Mueller had classic...

Chasing the Problem

Moments after the touchdown, the phone at the IL began ringing like a 1202 Program Alarm. NASA was calling and wanted to know what went wrong, demanding an explanation and a fix before the LM lifted off the surface in a few hours. The IL engineers understood that their computer was not operating at full capacity, but they did not understand why. They went to their simulators, in ''a frantic session,'' trying to recreate the problem. ''We worked all night and time was running short.'' Fred...

Programming the Moon Flights

With the exception of integrated circuits and extremely high reliability, the hardware for the Apollo guidance computer represented the state of the art when Apollo began. The same could not be said of the software and user interface. An aspect of the system barely envisioned when the program started, software turned out to be among the most difficult, and the most critical, components in the Apollo system. The software would carry all the burden of Richard Battin's complex guidance schemes. It...

A computer pregnant with alarm

This point had a manual check as well. The computer would not accept the radar data without Aldrin's OK. He was about to tell the computer to incorporate the radar altitude into its solutions when the unexpected occurred. Kranz was asking his guidance controller, ''Is he accepting it the radar data '' ''Program alarm,'' Armstrong called, a touch of urgency in his voice. Aldrin quickly keyed in Verb 90 Noun 50, asking the computer for the nature of the alarm. Armstrong read aloud the display...