Lunar Module Honored With IEEE Milestone

IEEE recognizes a piece of technology that got humans to the moon

5 August 2011

Millions of people watched on 8 July as NASA ended its 30-year space shuttle program with the final flight of Atlantis. On another July day—20 July 1969—a historic launch took place that had practically the whole world watching. The Apollo 11 mission put the first humans on the moon. That wouldn’t have been possible without the lunar module in which the astronauts landed safely. The module was developed by thousands of subcontractors and engineers from Grumman Aircraft Engineering Corp. (now Grumman Aerospace Corp.), in Bethpage, N.Y.


To honor the breakthrough, IEEE recognized the Grumman lunar module as an IEEE Milestone in Electrical Engineering and Computing on the 42nd anniversary of the historic moon landing.


ON A MISSION

Following U.S. President John F. Kennedy’s directive to put a man on the moon by the end of the decade, NASA sought out contractors in the early 1960s to build a spacecraft that could do the job. The agency decided to rely on a lunar orbit rendezvous (LOR) instead of direct ascent or Earth orbit rendezvous, which would have involved landing the entire Apollo spacecraft on the moon. The LOR method required the construction of a separate spacecraft that could land on the moon and ascend back to the command and service module in orbit around the moon. The lunar module blasted off from the moon’s surface to the command module, which had the propulsion, electric power, and space to carry the crewmembers back to Earth, re-enter its atmosphere, and land.


Competing against almost a dozen other companies, Grumman won the contract in 1962. The company was ready for the challenge; it had been researching LOR methods since the late 1950s.


Thousands of Grumman engineers working with subcontractors from companies including the MIT Instrumentation Laboratory, TRW, and Raytheon developed more than a dozen versions of the lunar module during the next few years. The initial design was the lightest and had only three landing legs. But if one of the legs had been damaged during landing, the craft would have become unstable. Another model with five legs was deemed too heavy. The chosen model combined the best features of the earlier prototypes and had four landing legs.


READY FOR LAUNCH

During the lunar module’s design phase, countless engineering achievements were registered, including an environmental control system that maintained the interior temperature between 18° and 21º in the cold of space. The spacecraft also had a complex landing radar and computer system that measured the delay between the transmitted and reflected microwaves from the moon’s surface to calculate the module’s proximity to the ground.


The craft’s S-band 2-gigahertz high-gain antennas made possible the transmission to Earth of live images of the moon landing. In addition, the lunar module’s guidance computer was the first computer to use ICs.


The first flight of the lunar module was unmanned. It was taken up to low-Earth orbit on the Apollo 5 mission on 22 January 1968 to test the descent and ascent propulsion systems.


Its first manned flight, a part of Apollo 9 on 3 March 1969, was used to test the separation and docking features in low-Earth orbit. A practice run of the lunar landing took place during the Apollo 10 mission on 18 May 1969. That flight tested all the phases of the mission except initiation of the powered descent that would be used to land on the moon.


On 20 July, the Grumman lunar module became the first vehicle to land men on the moon, as millions of people watched on television. The module, named Eagle, then safely returned the crew to the command module, which splashed down safely in the Pacific Ocean four days later.


The lunar module later was used aboard Apollo 13, launched on 11 April 1970. The mission was aborted when an oxygen tank ruptured, leading to a loss of oxygen and cutoff of electrical power in the service module. The crew, which shut down the command module to conserve its batteries and the oxygen needed for the last hours of the flight, relied on the Grumman lunar module’s resources, making it back to Earth safely on 17 April.


A Milestone ceremony was held on 20 July at the Northrop Grumman Aerospace Systems, Battle Management, and Engagement Systems Headquarters, in Bethpage. The building was built for the lunar module project. A plaque placed at the site reads:


“The Grumman Lunar Module was the first vehicle to land man on an extraterrestrial body, the Moon. Because it was designed to fly solely in space, its design, construction and testing continuously pushed the technology envelope for lightweight metals and unique electrical and electronic systems resulting in one of the most important and successful engineering achievements of mankind.”


For more information on this and other IEEE Milestones, visit the IEEE Global History Network.


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