On July 20, 1969, Armstrong and Aldrin made history when they took steps onto the moon for the first time, watched by millions around the globe. They planted the American flag and read out loud a plaque reading: “We came in peace for all humanity,” before returning back into Eagle to rejoin Michael Collins.
During their landing sequence, they encountered some difficulties due to alarms on their computer system soaring off repeatedly. After taking semi-manual control of their module to avoid an uneven terrain and eventually land safely in the Sea of Tranquility.
Mission Overview
The Apollo 11 mission marked an historic first in human space exploration. This first landing of astronauts onto the Moon and successful return was an extraordinary accomplishment for NASA and would serve as a model for subsequent lunar missions.
Apollo 11 featured three astronauts – Commander Neil Armstrong, Lunar Module Pilot Buzz Aldrin and Command Module Pilot Michael Collins – that launched from Kennedy Space Center on July 16, 1969 and broadcast their mission live to hundreds of millions around the globe.
After two-days of travel to the Moon, Columbia successfully docked their lunar module with their lunar module, Apollo 17. From there they deployed several devices including television cameras, solar wind composition experiments and seismic experiment packages on its surface before taking extensive photographs of both lunar terrain and their immediate environment.
Armstrong and Aldrin began preparing to land on July 20, and waited until just minutes before landing to activate their descent engine, which began propelling them toward the Moon about 102 hours 45 minutes into their mission.
After several hours, they opened their lunar module hatch and started climbing down from it. Armstrong made his historic first step onto the Moon at approximately 9:56 p.m. while proclaiming, “That’s one small step for man, one giant leap for mankind!” Aldrin soon after followed suit and together they spent 21 hours collecting 21 kilograms of samples as well as installing and photographing laser retroreflectors as well as taking photographs of themselves, their lunar module landing site and scientific equipment.
As they prepared to return, they jettisoned the ascent stage back onto the lunar surface before firing their service module’s engines to return into lunar orbit and connect back with Collins and rejoin his command module shortly afterwards.
At Apollo 11, one of the most noteworthy achievements was proving that Saturn V rocket could carry humans to the Moon, signaling that a fully functional lunar program could proceed despite prior technical problems such as fire on Apollo 1 launchpad that claimed three astronaut lives.
Apollo 11 Launch
Apollo 11 marked a turning point in NASA’s efforts to put men on the Moon. A massive undertaking, Apollo involved three main components – command and service module (CSM); lunar module (LM); and Saturn V rocket – designed to put humans there. CSM housed astronaut crew, equipment, spacecraft operation systems as well as scientific experiments set to take place during mission. While LM contained lunar surface landing gear as well as scientific experiments. Built within weeks by only eight individuals – giving astronauts more freedom in exploring lunar surfaces without feeling restricted by cramped conditions than ever before!
In addition to carrying a television camera that would transmit live pictures back to Earth, the Lunar Module also carried solar wind composition experiments; seismic experiment packages; and a Laser Ranging Retroreflector, which measured distances from it and the far side of the Moon using reflected light. Armstrong and Aldrin spent two-and-a-half hours during EVA-1 deploying and collecting scientific experiments before returning back into their command module for landing near Site 2 after reaching all scientific goals of mission 111 hours 39 minutes into mission.
Before landing, the astronauts experienced a series of frightening computer program alarms and navigation glitches that nearly cost them their lives. At one point when they were only 9,000 feet from landing on the moon’s surface, an alarm went off which no one in the crew could explain; fortunately guidance officer Steve Bales acting on input from back-room genius Jack Garman gave clearance for powered descent initiation (PDI).
Once they reached the Moon, Armstrong and Aldrin were welcomed with cheers of joy from around the globe as they emerged from Eagle’s landing gear in spacesuits to an applauding world. After sleeping that first night on the lunar surface, the astronauts returned the next day via the Lunar Module to Earth where they underwent another rigorous journey back. Once back home they were quarantined at a mobile quarantine facility until medical authorities could verify they were healthy without any potentially hazardous microbes from lunar surface which might have hitched a ride back from lunar surface microbes hitching ride with them from Moon surface or vice versa.
Apollo 11 Landing
Apollo 11 astronauts used their first lunar landing as an opportunity for exploration, testing their spacesuits, and collecting samples from the Moon. They collected 21.8 kilograms of lunar rock and regolith samples; traversed between one to two kilometers on the lunar surface; deployed experiments (such as seismometers for measuring moonquakes; laser-ranging retroreflectors; solar wind collectors etc); as well as collecting 218 kilograms worth of samples on that first visit to our satellite planet.
But the mission was far from smooth sailing. On their descent to the Moon, Armstrong and Aldrin were warned they were about to overshoot their planned landing site by approximately three miles; computer alarms that did not correspond with simulation results caused him to call Mission Control for guidance, which verified they could proceed safely.
Armstrong and Aldrin undertook an exhaustive checklist in the next two and a half hours to ensure their spacecraft would safely reenter Earth’s atmosphere upon return from its lunar mission. This involved inspecting every aspect of its systems as well as setting up various experiments–a lunar dust collector, laser-ranging retroreflector, solar wind sampler and seismometer to measure moonquakes–to ensure safety during their return home.
Armstrong called out their position to Mission Control throughout this period, including details like angle of landing point designator and descent speed. He also reported on altitude changes as it descended, which revealed a discrepancy of about 2,900 feet between their primary Guidance and Navigation System (PGNS) reading and that shown on landing radar; an issue known as delta-H.
Armstrong then assumed semi-manual control of the lunar module and guided its path away from West Crater and towards areas with less rocks – with just 25 seconds of fuel remaining for its descent, the LM was close to touching down on Earth.
On July 24, 170 hours and 15 minutes after its departure from orbit, the Lunar Module separated from its command module and parachuted down into the Pacific Ocean near 13 miles from USS Hornet – meeting both its national goal as well as setting up future exploration of other planets.
Apollo 11 Docking
Neil Armstrong and Buzz Aldrin were in the midst of a historic mission. After docking their Lunar Module “Eagle” to Columbia’s command module, they prepared for launch into lunar orbit while performing an elaborate maneuver that would enable them to switch between their command module and Lunar Module without leaving its landing site behind.
Once CSM and LM had separated from one another, they fired their propulsion systems to change their orbits and approach the moon. While the maneuver itself worked flawlessly, astronauts used an instrument called Body-Mounted Attitude Gyros to monitor spacecraft attitude (how it is pointed). Unfortunately, they weren’t designed to operate under lunar gravity; lunar gravitation caused their gyros to slow down significantly which in turn impeded astronauts reading data back from lunar gravity back home quickly enough.
Armstrong and Aldrin used their telemetry data to ascertain that they had drifted off course by approximately 300 miles per hour from their target orbit, however this wasn’t cause for alarm as NASA simulations indicated it wouldn’t impede with landing operations; plus they still needed several maneuvers before reaching safety.
About nine minutes prior to their scheduled landing site, Armstrong and Aldrin realized they would miss it by some distance. Not panicking–this was something they had anticipated–they needed to make some quick adjustments; specifically reducing their descent rate while simultaneously using less fuel from their descent engine, thus altering timing and impacting how much cushion was available during landing.
After 21 hours and 36 minutes on the moon’s surface, they safely returned to Eagle and undocked from CM. Collecting rocks and soil samples and deploying an array of scientific experiments (such as seismometer to detect moonquakes, solar wind collector, laser-ranging retroreflector), they returned back home safely with plenty of scientific experiments done successfully.