Mission Control had just instructed Aldrin and Armstrong in the LM to “go long” on their return home from space, in order to move themselves away from the Command Module and allow their service module to reach Earth before them on its reentry path. By doing so, Aldrin and Armstrong could potentially gain more time during reentry without interfering with a similar path for other modules that had strayed off course during launch.
But the switch didn’t turn, and the yellow light meant to indicate an issue with the hydrogen tank never appeared.
The launch
At 10:36 on July 21st, Armstrong and Aldrin left the Lunar Module (LM), rejoining Collins in the command module for one final time after spending 21 hours and 23 minutes traveling from Earth to lunar orbit insertion and back home again.
Two and a half hours passed as the astronauts explored the lunar surface with ease and joy, photographing its craters and boulders, collecting rocks for study piles, conducting scientific experiments (such as using seismograph to detect “moonquakes”, laser-ranging retroreflector that would reveal Earth’s distance from it precisely), planting an American flag as proof that they had completed this historic feat of exploration, and planting one as proof.
As they neared their landing site in the Sea of Tranquillity, an alarm sounded. Armstrong and Aldrin hadn’t come across error code 1202 in their training, leaving ground control unsure what action were necessary to deal with it.
After consulting with mission controllers and Grumman representatives, Kranz decided to inform the astronauts that their lunar landing might need to be aborted due to zero room for error: It was humanity’s inaugural voyage to the moon; without an intact lander they wouldn’t make it back alive.
Thankfully, the problem turned out to be only minor; a plug of ice had formed in an engine cooling line after shutdown and had caused pressure build up within. Re-entry burn’s heat quickly melted it, relieving pressure. Though potentially serious in nature, this was quickly handled by crew who continued their checklists without interruption.
On 22 July, the astronauts jettisoned the lunar module and took off with their service module from the moon’s surface, embarking on an exhilarating three-hour reentry journey back into Earth’s atmosphere before splashing down in the Pacific Ocean where they were recovered by USS Hornet. Amid all this global celebration, one minor glitch caused confusion: A Fisher Space Pen had broken off from an ascent engine arming switch without anyone realizing; they continued using it as normal without realizing its malfunction!
The fire
On January 27, 1967, NASA experienced one of its most heart-wrenching moments during a launch. Gus Grissom, Ed White and Roger Chaffee strapped themselves into an Apollo cabin atop two-stage Saturn rocket, when an electrical fire ignited in its pure oxygen cabin atmosphere and burned for minutes; killing all three astronauts through burns, smoke inhalation, and asphyxiation. Although such complex machines weren’t meant to always operate perfectly without incident, this fatal accident in Apollo still came as a shock; its first fatal fatal accident was just such an unexpected event that no one expected such tragic outcome would happen at all – nor expected it from NASA!
The Command Module (CM), a metal shell designed to house three astronauts for six days in orbit, caught fire after its wiring had been protected with Teflon insulation and covered in bundles. A spark likely leapt from one of those wires under Grissom’s footrest before spreading rapidly throughout the capsule’s interior; further pressurization could not open its door hatch without depressurizing all areas simultaneously.
Within seconds, the astronauts’ telemetry jumped dramatically, signaling their cabin was on fire. Soon thereafter, it could be seen on closed circuit TV in the blockhouse control center and Grissom announced, “Houston, we have a fire.”
Pad workers took several minutes to open both of the hatches on board the ship. But they were overwhelmed by heat, smoke and toxic propellant fumes as their gas masks were designed only to filter out hazardous propellant fumes; many passed out from these fumes.
17 seconds after the fire had broken out, Mission Control lost contact with astronauts – an inevitable event as their service module had come too close to ignite and cause further problems with Mission Control’s communications with them. The astronauts most likely succumbed to smoke inhalation or burns shortly after becoming trapped by flames, with any remaining life most likely ending due to asphyxiation. At last, their bodies were cremated, and a plaque commemorating each astronaut and date of death was placed on the pad. An exhaustive investigation led by an Accident Board and both chambers of Congress soon thereafter revealed that the fire had been caused by multiple factors, including poorly prioritizing schedule over safety. Subsequent design changes led to a much safer and more capable spacecraft which helped the US reach the moon before the end of decade.
The landing
Most people couldn’t comprehend the potential danger of Armstrong and Aldrin’s mission; however, inside NASA and within its lunar module it seemed as though everything would run smoothly; even so, shortly before half way, problems emerged for them both.
As Lunar Module “Eagle” separated from Command Module Columbia to begin a descent to the lunar surface, residual pressure within a tunnel that had linked them was not properly vented – giving an unexpected boost that altered Eagle’s planned path and altered its planned path significantly.
The crew only realized what had occurred minutes before landing at 9,000 feet above the Sea of Tranquillity. At this point, normally their computer would take control of piloting them safely down to their landing site; but Armstrong, as an experienced test pilot noticed that their computer was instead dropping them into an boulder-strewn crater instead of their desired spot. Armstrong quickly made adjustments by flipping a switch that sent their LM on an alternate route until its problem resolved itself – due to some ice formation in its engine’s heat shield, returning its vehicle back on course with normal trajectory.
Armstrong and Aldrin spent 21 hours exploring the moon’s surface and sleeping fitfully inside their cramped LM, all the while remaining alert for anything that might go amiss.
At one point, Mission Control issued an alarming message: “Eagle has become disoriented; instruct Collins to go aft omni.”
The alarm proved false, yet still managed to ratchet up tension for all three astronauts. Between phone calls, they drank water and snacked on candy bars.
After they reached the Command Module after an epic lunar voyage lasting 44 hours and 4412 minutes, they prepared for a long ride back. First they fired the Lunar Module’s ascent engines to rendezvous with the CSM in lunar orbit before jettisoning it and beginning their return journey towards Earth.
The rescue
The rescue mission was meticulously planned and practiced to avoid back-contamination with lunar microorganisms that might still remain inside Hornet spacecraft. A team from Navy’s Underwater Demolition Team were specially trained on Hornet for weeks in order to carry out these recovery operations, wearing special scuba gear that reduced exposure to potentially lethal organisms.
Lieutenant Clarence James “Clancy” Hatleberg was an exceptional leader of the frogmen. After hearing the astronauts’ shouts for help, he immediately went into action: opening up the command module hatch, retrieving a life raft from within its capsule, lowering it onto the ocean surface, closing vents on its service module that were jam-packed full with equipment, closing vents in its service module containing fuel cells to generate electricity and water, opening up vents on its service module containing equipment, closing vents on its service module and finally opening its hatch on its command module hatch flooded hatch.
Inside of the service module was an unstable hydrogen tank. Leakage would lead to carbon dioxide build-up, and so astronauts needed to increase pressure as soon as possible. A yellow light on the command module’s panel warned of low oxygen pressure in this same tank; however, due to faulty sensors this warning did not activate into an emergency red signal light warning of its own.
Mission Control quickly recognized the danger. They wanted the astronauts to use the service module’s main engine for an emergency U-turn and return home within two days, but due to limited power there wasn’t enough power available. Thus they devised a procedure designed for emergency use that utilized lunar module as a lifeboat.
At first, the astronauts remained in their capsules as USS Aquarius slowly approached. Over time, Armstrong and Aldrin emerged from their raft to climb aboard Billy Pugh net that was uploaded onto a helicopter carrying them back. A NASA flight surgeon was present during this process for medical evaluations before they were transported back to Hornet on Helo 66 helo.