Project Apollo was NASA’s second major effort to reach the Moon. Its primary objective was to land an astronaut crewed on its surface.
Before that could happen, several key advances had to be made first – and Gemini provided training for these advancements, including showing astronauts could endure long space flights.
Apollo 1
Apollo 1, now commonly referred to as Apollo 1, was being tested on Florida’s launch pad during rehearsal for its inaugural crewed mission. Something went wrong during that test and its cabin filled with pure oxygen, quickly setting everything ablaze in seconds and killing three astronauts: Grissom, White and Chaffee from smoke inhalation.
Fire was caused by combustible materials combined with an impractical design, making it hard to open the hatch quickly. NASA learned from their mistake, prioritizing noncombustible materials over schedule-oriented projects in their future endeavors.
Armstrong and Aldrin successfully reached the Moon despite some difficulties, using Eagle to dock to Collins’ command module and drive Liberty, a lunar rover, across 17 miles before collecting samples as they explored further parts of its surface. It marked the first mission using Lunar Rover technology which would enable future missions to explore deeper parts of lunar surface.
Apollo 2
Saturn V rocketed Apollo into orbit. Atop this giant rocket was the Command Module, designed to transport three astronauts. Additionally, two lunar modules would land on our natural satellite and return two astronauts back to CSM for continued lunar exploration.
Apollo 7, the inaugural Apollo mission, flew into low Earth orbit to test both the command module and lunar module, with Wally Schirra, Donn Eisele and Walter Cunningham serving as its crew members. They made history when they provided live television transmissions from space – the “Wally, Walt and Donn Show” soon becoming an immensely popular phenomenon.
Apollo 10 ended tragically when fire consumed its lunar module and killed Commander Thomas Stafford and Lunar Module Pilot Eugene Cernan, prompting NASA management to become ever more cautious: they “had much less trust in the Apollo systems than those operating them”, states geologist and former U.S. senator Harrison Schmitt.
Apollo 3
This mission marked an important step in human understanding of the Moon. For one thing, this was the first time humans drove a lunar rover and conducted numerous experiments proving Galileo’s theory that objects in space fall at an equal rate (without air resistance). They also collected 382 kilograms of samples including core samples and spectrographic studies from its surface.
The Apollo program utilized two spacecraft: the Command/Service Module and Lunar Module. While LM was intended to land on the Moon’s surface, CSM remained orbiting around it – this larger craft allowed three astronauts to travel together on missions.
Uncrewed test flights began in February 1966, and NASA managers felt confident enough in planning crewed missions despite Apollo 1’s disastrous fate. On April 28th 1966 during rehearsal for Apollo 1, fire broke out during rehearsal and tragically claimed Commander Virgil Grissom, Pilot Edward White and Engineer Roger Chaffee’s lives.
Apollo 4
The Apollo 4 mission served as an essential test of the spacecraft designed to carry astronauts to the Moon and fulfil President Kennedy’s eight-year goal: making history through human colonization of another world.
Armstrong and Aldrin utilized this mission to test out their lunar module Eagle after landing it in the Sea of Tranquility on July 20. After about two hours of moonwalking, they deployed seismometers to measure lunar quakes as well as laser retroreflectors used by astronomical observatories to measure distances between Earth and Moon, collecting 21.6 kilograms of samples and taking photographs along their travels.
The Saturn V rocket used for Apollo missions stood as tall as 36-story buildings and consisted of three stages. Within each stage was the Command Module, a capsule used by astronauts traveling between Earth and Moon under conditions more cramped than Mercury or Gemini programs; its Lunar Module landing module on the moon provided more room.
Apollo 5
NASA was ready to begin their next step after successfully completing the Mercury program of sending one-person crews into space: operating an Apollo spacecraft. While human lunar landing was still several years away, Apollo 5 served as an important systems test of what would eventually become their Lunar Module (LM).
On January 22, 1968, the Saturn IB rocket successfully launched and placed Lunar Module into lunar orbit. There were two key tests performed on Lunar Module; first was its ascent and descent engines which underwent a 39 second burn during what became known as “Fire in the Hole Test”, depicted on mission patches as such.
After checking out their systems aboard Eagle, Armstrong and Aldrin began their lunar walk at Station 1. Here they deployed seismometer and laser retroreflector instruments before collecting 21.6 kilograms of samples and surveying Camelot Crater and Shorty Craters for potential volcanic deposits.
Apollo 6
On April 4, 1968, Apollo Program’s second uncrewed flight launched from Earth was intended to demonstrate Saturn V’s capability of landing safely on a lunar trajectory. Unfortunately, severe vibrations during launch led to engine 2 malfunctioning and thus disallowing any return back home.
Engineers worked tirelessly to resolve an issue discovered shortly before liftoff, which turned out to be caused by a broken fuel pipe and caused Engine 2 to run out of gas, before successfully getting it back online and safely returning home.
The Apollo spaceflights culminated in July 1969 with Neil Armstrong and Buzz Aldrin’s first manned landing on the Moon. Over eleven years, astronauts spent 382 days exploring its surface before gathering samples to bring back home for analysis by scientists here on Earth. Analysis of rocks found there has demonstrated that our Moon is lifeless – its formation was caused by another large planet striking our early planet during formation.
Apollo 7
The Apollo program ran from 1961 to 1972 and was the largest research and development effort ever attempted in peacetime history. Employing over 400,000 Americans at its peak, it comprised half of NASA’s spending. Neil Armstrong and Buzz Aldrin became its famous protagonists upon landing on the Moon on July 21, 1969.
On October 11, 1968, Apollo 7 made history when its inaugural manned Apollo mission, Commander Donn Eisele and Lunar Module pilot Walter Schirra Jr, successfully entered Earth orbit for their maiden voyage together. They conducted tests of both spacecraft systems and supplies while taking panoramic pictures known as Earthrise to photograph our home planet from space.
Once separated from its mothership, the Lunar Module’s (LM) descent engine activated for Descent Orbit Insertion (or Pitch Over). Subsequently, its crew conducted one or more EVAs exploring lunar surface features and collecting samples between rest periods alternating with EVA exploration activities – providing crucial data that helped scientists confirm that Moon experienced catastrophic change 3.8 billion years ago.
Apollo 8
After uncrewed test flights and four crewed missions that demonstrated the safety of launch vehicles and spacecraft for astronauts, NASA decided to speed things up by embarking on an accelerated trip to the Moon. On December 21, 1968, Commander Frank Borman and Command Module Pilot James Lovell set sail aboard Apollo 8 from low Earth orbit for its Moon orbit mission; following an in-orbit detailed checkout of systems in second orbit, NASA officials reignited S-IVB third stage fuel for an initial translunar coast trajectory trajectory.
Mission participants traveled across the far side of the Moon where Lunar Module Pilot William Anders’ photograph of Earth became one of the most iconic images ever captured on film. After 21 days spent orbiting over 31 times over the Sea of Tranquility, their spacecraft returned back into Earth’s atmosphere and splashed down safely in the Pacific Ocean on July 24.
Apollo 9
The Apollo program ran from 1961 to 1972 and culminated with 12 spaceflights, six lunar landings and numerous lunar sample collection missions by astronauts studying the Moon to help scientists better understand its formation and that of our planet and natural satellite.
Apollo 4 (AS-501), launched November 9, 1967, reconfigured both the Saturn V rocket and command module for use during manned lunar exploration flights, as well as testing its heat shield against trans-lunar reentry reentry conditions.
James McDivitt, David Scott and Russell “Rusty” Schweickart performed docking maneuvers in Earth orbit to prepare for their lunar landing mission. To commemorate how each module looked when shipped to NASA, they gave each an amusing name (Gumdrop for command module and Spider for lunar module). Once separated from one another they conducted an extravehicular activity which ended sooner than anticipated.