The arrival on the Moon was one of the most notable scientific and technological milestones of the 20th century. This momentous achievement continues to resonate with everyone, both those who witnessed it firsthand and those who have seen the images and audio recordings. More than 40 years ago, when personal computers and mobile phones were still in development, humanity took monumental strides in space exploration. But what technological advancements facilitated this giant leap for mankind?
Examining the details behind the computers, cameras, and other devices used during the Apollo 11 mission reveals the sheer ingenuity involved. Join us on a journey through time and space to uncover the technologies responsible for getting humans to the Moon, where they could walk, explore, and narrate their experiences back to Earth.
Apollo 11: The Journey Begins
The Apollo 11 mission was the eleventh in NASA’s ambitious Apollo program, which spanned a total of 22 missions from the 1960s to 1972, with 19 being successful. Before Apollo 11, the launches were primarily unmanned until mission 8, which became the first to orbit the Moon. Each mission utilized the Saturn rocket, specifically the Saturn V for Apollo 11, measuring 110.64 meters in height and weighing in at 2,700 tons when fully fueled—the largest rocket NASA ever built. The Saturn V used a mixture of fuels, including oxygen, kerosene, and liquid hydrogen, across its three stages: S-IC, S-II, and S-IVB.
While the Saturn V was pivotal for launch, it did not land on the Moon. Instead, it deployed two modules: the Command and Service Module (CM) and the Lunar Module (LEM). The CM housed the propulsion system to enter and exit lunar orbit and could accommodate three astronauts, while the LEM was specifically designed for lunar landings.
A Unique Descent
The LEM detached from the CM as it entered lunar orbit, making its descent onto the Moon’s surface. This module’s legs were engineered to handle the weak lunar gravity of 1.6 m/s² but couldn’t support its frame in Earth’s gravity (9.8 m/s²). It could carry only two astronauts for the landing phase.
During descent, speeds escalated up to 9,000 kilometers per hour due to lunar gravity, raising questions about braking methods. Hypergolic braking was employed, using compounds like hydrazine and nitrogen tetroxide—substances that ignite spontaneously upon contact—alongside engine shutdown.
The Unsung Heroes: Apollo 11’s Computers
Understanding the computing technologies used in the Apollo 11 mission involves examining both ground-based systems and onboard computers. At the time, computers were rare and far from common household items.
On Earth, NASA utilized the IBM System/360 75 mainframe at the Goddard Space Flight Center and the Manned Spacecraft Center in Houston. The AGC (Apollo Guidance Computer), manufactured by Raytheon and designed by MIT Instrumentation Laboratory, was instrumental onboard. It marked one of the earliest uses of integrated circuits, featuring one in the LEM and another in the CM.
Remarkable Specifications
The AGC’s storage capacity of 36,864 14-bit words and 2,048 words of RAM might seem underwhelming by modern standards, but in the 1960s, its capabilities were groundbreaking. The computer was roughly equivalent in memory to a Commodore 64 (1982), yet only a fraction of the performance of an IBM XT (1981). The onboard processing speed registered at just 0.043 MHz, starkly contrasting with today’s advanced microprocessors.
The software powering the Apollo mission was equally noteworthy. Created over seven years by a team of 300 engineers and scientists at a cost of approximately $46 million, the program, known as LUMINARY, was initially produced using punched cards. Allan Klumpp, a mechanical engineer, played a vital role in devising the calculations and diagrams necessary for lunar landing operations.
Communicating from the Moon
Many of us are familiar with the iconic images and the memorable phrase uttered by Neil Armstrong: “One small step for man, one giant leap for mankind.” The transmission of these images was no small feat, given the technology of the time. The video format transmitted 525 scan lines at 30 frames per second, with a camera specially designed to withstand extreme lunar temperatures.
Audio communications between the crew and ground control were broadcast globally, although private discussions between Armstrong and Aldrin were recorded and preserved. Each Apollo mission spacecraft included voice recorders to capture conversations, digitization of which commenced as the 40th anniversary of Apollo 11 approached.
The Engineering Marvel
The desire to touch another celestial body propelled advancements in engineering. The onboard computer, a remarkable feat for its time, measured 32 x 61 centimeters and weighed 32 kilograms. Compared to contemporary computers, it was a significant achievement in miniaturization.
Today, elements from this historic mission can be explored at institutions such as the Smithsonian National Air and Space Museum in Washington, D.C. The Apollo 11 mission serves as a testament to human ingenuity and technological prowess, a milestone forever etched in history.