In 1969, planetary science was still relatively young. One of its most famous moments occurred on July 20, when Neil Armstrong and Buzz Aldrin left Columbia and entered their lunar module, Eagle.
Armstrong used Eagle’s reaction control system to guide their landing site in the Sea of Tranquility.
Mission Overview
Nasa embarked on its most ambitious commitment of all time as part of the Space Race: sending humans to the Moon. The Apollo 11 program required 400,000 workers and cost $25bn (PS16bn). Three astronauts, Neil Armstrong, Buzz Aldrin and Michael Collins were chosen to travel into space aboard this craft for this complex mission that had taken years of technical planning and design to be implemented successfully.
Launch occurred on July 16 and began their historic flight. Stage one fired to get them into orbit while stage two shot off to launch them off earth’s gravity well and onto their lunar trajectory. Finally after nine hours, Columbia separated from Eagle, becoming its own module with Armstrong and Aldrin joining it as lunar landing craft astronauts; Collins remained behind to remain as commander.
On July 20th, Armstrong and Aldrin entered the lunar surface via the LM hatch and two and a half hours later Armstrong placed his foot onto it and said: “That is one small step for man, one giant leap for mankind”. 530 Million people witnessed this historic moment.
On their one moonwalk, astronauts deployed seismometers, laser reflectors and solar wind detectors, collected rock samples to send back home, photographed the landscape and left behind an American flag while Aldrin read an inscription plaque and sketched sketches of their surroundings – with cameras inside and outside their Lunar Module (LM) recording images of their work – providing scientists with invaluable insight into its composition, structure and history.
Preparations
As NASA made progress towards President Kennedy’s goal of landing man on the Moon, mission managers became confident that Apollo 11 (scheduled for launch in July) would achieve it. This confidence stemmed from its successful test flight of the Lunar Module, or LM, in May which successfully separated from and orbited around the lunar surface before returning back into Earth orbit.
On Earth, the crew was training and preparing for their lunar expedition through various tests using the Lunar Module. These included using it to practice various tasks – such as deploying scientific instruments or collecting rock samples – while wearing extravehicular mobility units (EMUs) to simulate entering lunar territory.
Astronauts also used the Lunar Module’s onboard computer as part of their practice missions and to guide their return journey home from space. Though relatively basic by modern standards, this computer operated by using punch cards to store instructions that were then fed into an inertial guidance system before being translated into actions by onboard accelerometers.
Armstrong and Aldrin made history on July 21, 1969 by landing Eagle on the moon’s surface for their inaugural lunar exploration mission. Over two hours and 31 minutes, they traversed it, conducting numerous activities and using scientific instruments they brought with them to explore every inch.
As soon as it was time to return, Armstrong and Aldrin fired up their ascent engine – the most critical event of their mission; had it not fired as planned, returning safely would be impossible. Luckily, it worked perfectly as planned and Armstrong and Aldrin returned safely just hours later.
Launch
In July 1969, Neil Armstrong, Buzz Aldrin and Michael Collins embarked upon one of the greatest daredevil feats ever attempted by humans. The Apollo 11 lunar landing marked a massive national effort by the United States to beat Soviet Russia in the race to put men on the Moon; an event so groundbreaking it even amazed their rivals! It marked a historic turning point that shocked even them!
On July 16th, a Saturn V rocket lifted off from Cape Kennedy. Following a short trip into Earth orbit, its upper stage separated from the command module and started its trajectory towards the Moon; three days later Apollo 11 entered lunar orbit.
A crew in biological isolation suits, known as Eagle, was on board their lunar module shortly before launch. Once checked by Mission Control, Commander Charles “Pete” Conrad and Pilot Richard F. Gordon settled into Eagle in preparation for lunar descent. At that same moment, however, a 1202 program alarm – warning that Apollo guidance computers had become overloaded – signalled that landing may proceed despite any apparent danger; mission controllers decided against postponing lunar landing by cancelling it altogether.
Armstrong became the first human to set foot on the Moon when he emerged from Eagle, followed 19 minutes later by Aldrin. Millions watched them explore its surface under gravity only one-sixth as strong as that of Earth, using seismographs to detect lunar quakes and laser reflectors to bounce beams back from it and transmit data to Mission Control in Houston.
After 21 hours and 36 minutes on the Moon, astronauts returned to their lander and rejoined Collins in the command module. From there they made a descending pass over the Sea of Tranquility before landing on its surface using an inflatable landing module with its robotic arm for sample collection before using another robot arm to transfer their samples back onto Earth’s surface. As a precaution against “moon germs”, two hours were then spent in quarantine aboard USS Hornet before splashing down in Pacific Ocean on July 24.
Landing
In July 1969, Neil Armstrong and Edwin “Buzz” Aldrin of Apollo 11 made history when they became the first human ever to set foot on the Moon. Leaving historic boot-prints behind on its surface, they conducted many experiments and observations that will never be repeated again on our home planet; sent telegrams home, collected rock samples from Apollo 11, as well as maintaining constant communication with Mission Control – something no human had done previously.
On July 16 morning, they launched from Earth aboard a Saturn V upper stage rocket and three hours later the astronauts separated into Columbia and Eagle for lunar module use. Following an initial lunar orbit 111 by 306 kilometers and subsequent engine burn, their orbit slowly deviated to 100 by 113 kilometers elliptical.
Once Eagle had been thoroughly evaluated, its systems checked, the astronauts began their descent towards the surface. When Armstrong descended down his lunar module ladder, television cameras captured his first steps upon reaching the Moon and recording them; as soon as he reached its surface he announced: “That’s one small step for man; one giant leap for mankind.”
Armstrong and Aldrin spent 21 hours 38 minutes exploring the lunar surface during their moon walk, using tools such as seismometer to detect moonquakes and laser retroreflector to enable astronomical observatories on Earth to precisely gauge distance between Moon and Earth. Furthermore, they took numerous photographs as well as collecting 23 kg (50 pounds) of rocks and soil samples from the lunar surface.
At various points during the landing sequence, various obstacles arose that required Armstrong and Aldrin to use their training and trust their procedures in order to overcome them. They encountered an unusually large number of boulders at West Crater that needed semi-manual control to get around; their landing sequence required semi-manual control in order to navigate around these obstructions.
Return
On July 24, 1969, Neil Armstrong and Buzz Aldrin successfully accomplished their mission and returned to Earth via Eagle. For the first time ever in human history, humans had set foot on another world, spending 2.5 hours roaming about, installing scientific instruments, taking samples, all with gravity only one-sixth as strong as that on Earth. Millions worldwide watched live as Neil and Buzz began their return home via television broadcast.
The astronauts docked with Columbia, their Command Module that had carried them from low Earth orbit to the Moon and back again, and spent two days preparing for landing – knowing that it would likely be dark when closest approach occurred – until finally being allowed by NASA to land safely.
Once they were prepared, the astronauts fired up their descent engine and gradually decreased their orbit to 111 by 306 kilometers – an essential step that allowed them to precisely position themselves where it would give their spacecraft the best chance of landing safely.
As they approached the lunar surface, Armstrong used reaction control to move his spacecraft subsequently until he located an ideal area from which to launch their descent. Once there, he pressed “contact”, resulting in three probes measuring 172 cm (68 inches) making contact with the ground, within one and a half minutes they had touched down in what is known as “The Sea of Tranquility”
So they waited until it was the right time to deploy the main landing gear, then fired up their rocket engines again. The first stage burned for six minutes and two for the second stage before propelling both Command and Service Modules at speeds that would lead them back home to Earth.