Raytheon

Apollo DSKY

DSKY: A historic first in Human-Computer Interface

The DSKY was a historic advancement in how humans interacted with computers; it was the first time humans could ask questions and get immediate answers from their system. It was also the first time human lives depended directly on their computers. Instead of a bulky CRT display and keyboard, Apollo astronauts used the Display Keyboard (DSKY), a simple interface to the Apollo Guidance Computer (AGC), one of the first integrated circuit-based computers. The DSKY, designed by the Massachusetts Institute of Technology and manufactured by Raytheon, used LEDs and buttons to run control guidance, navigation, and control programs during the Moon landing.

Flying a spacecraft with nouns and verbs

The Apollo DSKY consisted of status lights, numerical indicators, and a small numerical onboard keyboard that allowed astronauts to enter numerical codes in a verb-noun order to query flight data. The Apollo DSKY contained 19 keys and a 21-digit display. Each Command module had two DSKYs—one on the main control panel and one in the lower navigation bay. Each Lunar Module had an identical DSKY.

Astronauts affectionately referred to the AGC and the DSKY as the “Diskee.” The simple yet powerful interface acted as an additional crew member, allowing astronauts to adapt to error conditions and manage safe landings.

Before DSKY, computers were addressed by stacks of punched cards and answers came hours later in the form of a paper print-out. To control their spacecraft, the astronauts needed immediate answers, which necessitated a revolution. DSKY is historic for pioneering “Humans in the Loop.”

IMAGES

The Display Keyboard, or DSKY for short, was not a computer. It was a revolutionary interface that allowed Apollo astronauts wearing heavy gloves to operate their onboard Guidance Computer. Each task for the computer was entered with a two-digit noun and a two-digit verb. So with a minimum of button pushes, the astronauts were able to pilot their spacecraft to the lunar surface and back.

Visible below the DSKY is the list of "Nouns" and "Verbs" the astronauts used to execute commands and guide the spacecraft.

Margaret Hamilton was just 30 years old when she became director of the Software Engineering Division of the MIT Instrumentation Laboratory. This division developed onboard flight software for NASA's Apollo program. She appears here with a huge stack of print-outs of the Apollo Guidance Computer's software

For her contribution to the DSKY and Apollo program software, Margaret Hamilton received the Presidential Medal of Freedom in 2016.

The DSKY had to be small enough to fit in the cramped quarters of the Apollo Lunar Module. It was the way the astronauts talked to their onboard "Apollo Guidance Computer."