The Lunar Excursion Module (LEM), commonly referred to as LM, enabled astronauts to land on the Moon. It consisted of two sections; its gold-and-black lower section known as the descent stage housed a rocket engine.
Armstrong and Aldrin utilized Columbia as their means to land on the lunar surface and return back to Columbia’s orbiting command module, Columbia.
Launch
As the entire world watched, two astronauts made history when they launched from Kennedy Space Center aboard a Saturn 1-B rocket in their command module accompanied by service and lunar modules.
Apollo launched into space after six minutes of second stage firings that propelled it at an acceleration of up to 25,000 mph, then reinitiated as its third stage to place it into an earth orbit stable orbit.
At this moment, astronauts were amazed to witness their spacecraft ascending above the lunar surface and slowly approaching it. Finally, the lunar module’s descent engine was activated and it started its safe trip towards its destination.
At the Sea of Tranquility, Armstrong stepped out of Eagle and announced: “That is one small step for man and one giant leap for mankind!” During their 21 hours on the surface they collected 21.6 kilograms of samples while also using seismometers, laser reflectors that measured distance between Earth and Moon bodies, seismometers, seismographs and an apparatus designed to capture samples of solar wind.
Orbit
After one and a half Earth orbits, Apollo 11’s S-IVB stage was restarted for its second burn which propelled it into translunar orbit – setting in motion a three day journey towards its target destination, monitored by Mission Control.
Command Module Pilot Michael Collins and Lunar Module Pilot Edwin “Buzz” Aldrin made history when they arrived on the lunar surface on July 20, 2012 via an interconnecting tunnel from CSM Columbia. While on their 3 day, 240,000 mile trip, they conducted experiments, deployed a television camera that transmitted images back to Earth and took many photographs of their surroundings.
As they approached the Moon, Apollo 11’s LM fired its engines to break into lunar orbit and enter the Sea of Tranquility. Once there, they declared their cargo of lunar dust and rock and underwent customs inspection before departing their LM. Neil Armstrong became the first human to step on its surface – famously saying his famous words: “That’s one small step for man; one giant leap for humanity”. Unfortunately he would never return.
Landing
At 02:56:15 UTC on 20 July, Armstrong opened the Eagle’s hatch and descended its ladder onto the lunar surface, followed shortly by Aldrin. Their two and half hour moonwalk comprised deployment of science experiments, photography of surroundings, displaying of an American flag for display purposes, reading plaques from past missions and collecting soil and rock samples for analysis back home before discussing activities via radiotelephone with scientists at MIT as well as President Richard Nixon.
Once back inside the LM, the astronauts took numerous pictures with still and motion picture cameras of its docking tunnel with Columbia and surroundings; two TV transmissions took place along the translunar coast – including sending out one transmission with color TV pictures from the Moon itself!
On July 21, a two-minute and 30-second firing of the SPS achieved final midcourse correction for Apollo 11. They splashed down in the Pacific Ocean at 12:50 GMT and were recovered by USS Hornet; 21 days after landing they entered a mobile quarantine facility for observation, yet showed no indications of disease.
Return
Armstrong and Aldrin completed an exhaustive checklist after their lunar landing to ensure their spacecraft was fit to return home. Due to “excitement,” they elected not to take advantage of an optional 4-hour rest period; although, more likely, this decision was driven by too many tasks that needed doing before departing on their journey home.
On their return journey, a computer was used to oversee and monitor their spacecraft. While its basic design made it less accurate than modern computers, its inertial guidance system consisted of accelerometers which detected every movement within their craft – data was input using punch cards by astronauts themselves.
Once docked at Columbia, Armstrong and Aldrin used vacuuming equipment to collect much of the lunar dust that had settled onto their suits. They took photographs of lunar terrain, their scientific equipment deployed there as well as each other; taking rock samples back for analysis on Earth.