The Apollo missions were a series of space flights that culminates in the first human landing on the Moon on July 20, 1969. Around 650 million viewers worldwide witnessed Neil Armstrong and Edwin “Buzz” Aldrin take their steps onto its surface for this momentous occasion.
After departing Columbia, the astronauts entered Eagle and conducted three moonwalks to collect over 250 pounds of samples – an effort which continues to yield scientific dividends today.
Apollo 1
Roger Chaffee, Virgil “Gus” Grissom and Edward White spent months prior to Apollo 1 (at that time known as Project Mercury) working hard towards meeting President JFK’s challenge of landing men on the Moon within 10 years. They were completely committed to their task and willing to adapt as issues arose during the mission.
However, despite extensive testing of systems on launch pad tests, they failed to simulate flight conditions and the fire that killed astronauts was due to an underlying fault in spacecraft design.
Engineers had chosen to fill the Command Module’s interior with pure oxygen rather than air and nitrogen mixture found on Earth, as this would enable faster escape. Unfortunately, this decision caused its hatch to be extremely difficult to open under emergency conditions: typically taking three seconds with a ratchet-type device to release one latch (Freiman and Schlager 1995).
Apollo 2
Armstrong and Aldrin successfully separated from the CSM aboard the LM and embarked on their inaugural lunar surface EVA. While on their excursion they collected parts from Surveyor III spacecraft, deployed an experiment package featuring seismometers, and set up a laser retroreflector to measure distances.
They also took the famous “Earthrise” photo that would inspire environmentalists and activists alike. While on board, astronauts noticed a whistling noise likely due to interference between LM and Command Module.
Apollo 9’s success can be measured against its reputation as a dress rehearsal for Apollo 11. For starters, astronauts remained in lunar orbit for an extended period and successfully used an LRV (Lunar Roving Vehicle).
This mission marked the official conclusion of NASA’s Mercury program and marked its formal demise despite tragic accidents such as those which killed Virgil “Gus” Grissom, Edward White and Roger Chaffee; nevertheless the Apollo program continued to thrive and expand over time.
Apollo 3
Once Sputnik stunned the US with its launch, America responded in full force with its own space race. Mercury and Gemini programs used rockets capable of getting astronauts into low Earth orbit; however, NASA’s Apollo program provided much larger vehicles capable of reaching orbit around the Moon.
On January 27, 1967, just five minutes after liftoff, astronaut Gus Grissom’s shout pierced through the chaos caused by an unexpected fire within their spacecraft and claimed all three crewmembers’ lives – Ed White and Roger Chaffee had also perished in this catastrophic tragedy.
Accident investigations revealed shoddy workmanship and lax safety standards, and this severely rattled NASA managers at just the moment they needed to take big risks in order to meet an end-of-decade lunar landing goal. A new Apollo spacecraft was then redesigned, featuring three modules: command module (CM), service module (SM), and lunar module (LM), all intended to transport two astronauts directly from Earth orbit to lunar surface and support them there before returning them back home again to orbital orbit via lunar module SM and lunar module LM).
Apollo 4
After the fatal Apollo 1 fire of 1966, NASA engineers took steps to ensure their new rocket and spacecraft were safe for launch – successfully doing so, with Apollo 4 test flight being successful.
Saturn V’s S-IC stage with five Rocketdyne F-1 engines generated 33,360 Kilonewtons of lift off thrust. Its purpose was to propel this massive rocket into space.
S-IVB stage then launched Saturn V and an Apollo command/service module modified from Block I (CSM) into an elliptical parking orbit of 188 kilometers around Earth. After two orbits, S-IVB fired again to reorient itself and increase CSM velocity towards an artificial lunar return velocity simulated lunar return velocity that lasted 367 seconds before an LES lightweight booster made of cork and fiberglass jettisoned itself over top of ascending spacecraft.
Apollo 5
Apollo 5 marked NASA’s inaugural manned lunar module flight. To prepare, its crew spent two days training at Grand Canyon University where they learned how to collect and study rock samples for collection purposes.
One of their key objectives was to recover Surveyor III, a robotic spacecraft which had been orbiting the Moon for over two years. They demonstrated a precision landing and installed an experiment package containing seismometer.
The crew mated the LM and CSM together and completed all maneuvers needed for lunar orbit, including simulating an abort by firing 39 second burn of descent propulsion system throttle settings that replicate actual conditions during an abort procedure.
The crew also used their LM to land and survey its surface, searching for volcanic rocks in Fra Mauro Highlands and discovering that plants in areas exposed to cosmic radiation longer experienced smaller growth in regolith beds than elsewhere. This knowledge proved essential when Apollo 12 included a full dress rehearsal lunar landing mission.
Apollo 6
From 1968 to 1972, 12 astronauts traveled aboard NASA’s Apollo spacecraft and traveled to the Moon. There, they collected rocks and data which have helped scientists better understand how our planet formed over time and whether Moon may have had any influence on this.
This mission tested the Lunar Module’s capabilities. Two astronauts would travel down to the lunar surface before returning back up into orbit via live television broadcast. All three crew members developed severe head colds during this mission but remained focused on meeting its goals.
Apollo 15 marked one of the final, and most ambitious Apollo missions ever attempted. Astronauts James McDivitt and Rusty Schweickart undertook an ambitious experiment when they separated the lunar module from the command module to conduct system tests before driving their lunar rover for six hours before returning back to orbit via command module. At its height, this massive research and development program employed over 400,000 Americans while costing approximately $257 billion today in 2020 dollars.
Apollo 7
After the deaths of Virgil Grissom, Edward White and Roger Chaffee on Apollo 1, NASA made changes to its design of manned spacecraft. Instead of Gemini and Mercury spacecraft’s mixed oxygen/nitrogen atmospheres, Apollo command module would use pure oxygen; this presented an extreme fire risk as any spark within could quickly ignite within its sealed capsule and potentially explode into an explosion.
Commander Wally Schirra and Lunar Module Pilot Donn Eisele experienced ongoing nausea and equipment failure throughout their 11-day mission. Additionally, Schirra experienced severe head cold symptoms which are especially unpleasant in zero gravity; due to mucus accumulation due to zero-g, mucus cannot drain away properly resulting in increased congestion resulting in much tissue consumption as well as aspirin and decongestants for relief.
Schirra and Eisele were concerned upon reentry that their helmets, which did not feature visor openings like those worn by Mercury and Gemini astronauts, might prevent them from blowing their noses to relieve sinus pressure, thereby risking barotrauma to their ears.
Apollo 8
Apollo 8 had an audacious plan: they intended to circumnavigate the Moon in just eight days! This was only their second manned Apollo Command/Service Module (CSM) flight and third launch of their Saturn V rocket.
The astronauts planned on conducting several important tests. They planned on conducting a photographic survey of both sides of the lunar far side with stereo photographs and making geologic observations in preselected locations as well as testing the Lunar Module lander.
On Earth, millions were watching with immense curiosity. Busloads of newsmen filled Cape Canaveral roads while crowds filled special viewing stands.
Jim Lovell and William Anders were exhausted, having taken sleeping pills which didn’t help, only to keep waking up to watch television. Lovell insisted he continue operating the camera; Anders agreed as long as he could sleep during his shift; finally they settled upon an agreement: Lovell would rest while Anders operated their navigation sextant for navigation purposes.
Apollo 9
Apollo 9, launched in March 1969, was the inaugural test flight of the lunar module (LM), a spider-like spacecraft intended to transport astronauts to the Moon. Once released from orbital control by the S-IVB third stage rocket booster, both CSM and Lunar Module spacecraft docked together successfully and completed their mission successfully.
Commander James McDivitt and Lunar Module Pilot David Scott performed tests of Lunar Module systems critical to their landing mission, such as its descent engine for maneuvering in space and use of portable life support system backpack during 46-minute spacewalk. In addition, this mission tested separation between man and spacecraft – key when sending a lander out alone toward the moon – before finally returning back home after 10 days, splashing down near Bermuda Islands in the Pacific Ocean.