Every Apollo Mission

We trace the Apollo program from Cold War origins to its collaborative finale, showing how disciplined engineering turned an audacious goal into reality.

Let’s start with a list of all the missions:

Uncrewed Test Missions

• Apollo 1 (AS-204) – Intended to be first crewed flight; crew (Gus Grissom, Ed White, Roger B. Chaffee) tragically killed in launch pad fire during pre-launch test – January 27, 1967
• Apollo 4 (AS-501) – First uncrewed Saturn V test flight – November 9, 1967
• Apollo 5 (AS-204) – Uncrewed test of Lunar Module in Earth orbit – January 22, 1968
• Apollo 6 (AS-502) – Second uncrewed Saturn V test flight – April 4, 1968

Crewed Missions

• Apollo 7 – First crewed Apollo flight; Earth orbit – October 11–22, 1968
• Apollo 8 – First crewed flight to orbit the Moon – December 21–27, 1968
• Apollo 9 – First crewed flight of Lunar Module in Earth orbit – March 3–13, 1969
• Apollo 10 – Full dress rehearsal for Moon landing; crewed lunar orbit – May 18–26, 1969
• Apollo 11 – First Moon landing (Neil Armstrong, Buzz Aldrin) – July 16–24, 1969
• Apollo 12 – Second Moon landing – November 14–24, 1969
• Apollo 13 – Intended third Moon landing; aborted after in-flight accident – April 11–17, 1970
• Apollo 14 – Third Moon landing – January 31–February 9, 1971
• Apollo 15 – Fourth Moon landing; first use of Lunar Roving Vehicle – July 26–August 7, 1971
• Apollo 16 – Fifth Moon landing – April 16–27, 1972
• Apollo 17 – Sixth and final Moon landing – December 7–19, 1972

Apollo Applications / Skylab & Apollo–Soyuz

• Skylab 2 (Apollo CSM mission to Skylab) – May 25–June 22, 1973
• Skylab 3 – July 28–September 25, 1973
• Skylab 4 – November 16, 1973–February 8, 1974
• Apollo–Soyuz Test Project – First joint U.S.–Soviet space mission – July 15–24, 1975

THE SPACE RACE BEGINS

1940s: With World War 2 over, aeronautical focus shifted to new technology, mostly scrounged from the Germans; advanced jet engines, and rockets. After the war, the US had taken over 100 V-2 rockets, and the Soviet Union obtained V-2 parts and documents— the Soviets had many Nazi rocket scientists working for them, while the US had Wernher von Braun himself.

In 1948, hostilities between east and west would grow, and by 1949 – aided by espionage – the Soviets acquire the nuclear bomb. Among the projects being pursued by the Soviets include long range delivery methods for nuclear weapons, nuclear capable missile systems.

Despite the overwhelming focus on explicit weapons systems, the focus will soon shift slightly. In October 1951, Soviet rocket engineer Mikhail Tikhonravov publishes an article in the Young Pioneers youth magazine entitled “Flight to the Moon”. He raises the hopes of young people for the expansion of rocket technology – not for producing weapons, but for travelling into space. He mentions Konstantin Tsiolkovsky – a reclusive Russian rocket scientist, who had been one of Von Braun’s inspirations – saying “We do not have long to wait. We can assume that the bold dream of Konstantin Tsiolkovsky will be realized within the next 10 to 15 years.”

Collier’s magazine in the US writes its own multi part series ‘Man Will Conquer Space Soon!’, with articles by Wernher von Braun, Heinz Haber and Willy Ley, detailing von Braun’s plans for manned spaceflight.

Animals were used early to validate life-support and re-entry systems before human flights. The United States flew suborbital biomedical tests using captured V-2 rockets, notably Albert II (a rhesus monkey) on 14 June 1949, who reached space but not orbit and did not survive landing. The first animal to orbit Earth was the Soviet dog Laika aboard Sputnik-2 on 3 November 1957; that spacecraft had no recovery system, and Laika did not survive. The first successful orbital flight with recovery came with Soviet dogs Belka and Strelka on 19–20 August 1960. Data from these missions established baseline physiology, validated cabin environments, and informed risk controls for the first human spaceflights.

In 1955, public interest in both Russia and the US was at an all-time high, spurred on by the airing of a Disneyland episode entitled ‘Man in Space’, featuring von Braun, Willy Ley, and Heinz Haber, and received by an incredible audience of 40-42 million people!

On July 29, 1955, the space race begins. Huge interest exists in the public and government, while the military sees potential in funding the advancement of precision rocket technology. That afternoon, the US announces their intention to launch artificial satellites for the upcoming International Geophysical Year – or IGY – which will start in July 1957. Five days later, the Soviets respond, asserting they too will launch satellites in the near future.

In a short matter of time, the Soviets fulfill their promise first. Using ICBM technology, they launch Sputnik-1 on October 4th, 1957. Weighing in at 83.6 kilograms, it is significantly heavier than the first US satellite to reach orbit, Explorer 1 on January 31, 1958, that weighed around 14 kilograms. Sputnik makes international news, marking a major leap forward.

President Eisenhower addresses the public on November 7th, 1957, attempting to quell fears of a potential imbalance, given the Soviets newfound superiority in this sector. Eisenhower announces “we need scientists in the ten years ahead…scrutinize your school’s curriculum and standards…meet the stern demands of the era we are entering.”

On January 31st,1958, Explorer 1 was launched. Then on July 29th, Eisenhower formally signs the National Aeronautics and Space Act, turning the National Advisory Committee on Aeronautics into NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More.

By 1959, the Soviets led the space race. Over the course of the year, they would make 3 landmark achievements, one for each of the first three Luna missions. Luna-1 would mark the first flyby of the moon and became the first spacecraft to enter heliocentric orbit. Luna-2 would be the first artificial object to touch the surface of the moon, while Luna-3 takes the first photo of the far side of the moon.

APOLLO PROGRAM BEGINNINGS IN THE 1960s

In the 1960s, the space race will enter its most crucial phase, putting men into space, and eventually onto the moon. While the 50s belonged to the Soviets, this next decade will see far broader advances in American space technology.

The Apollo program (publicly announced in July 1960) was conceived during the Eisenhower administration as a three-man follow-on to Mercury, with options ranging from Earth-orbit operations to circumlunar and eventually lunar landing. The US has announced its intentions to put a man into space as part of Project Mercury; the first flight being Mercury-Redstone 3, scheduled for May 5, 1961. Then, in another shocking show of force, the Soviets beat them, launching Yuri Gagarin into space aboard Vostok-1 on April 12, for the first human orbital spaceflight.

Mercury-Redstone 3 is nevertheless a success, the first US human suborbital spaceflight. Project Gemini would see similar success. However, Soviet dominance thus far has become a powerful motivator to aim higher and set more ambitious goals in shorter time frames.

On May 25, 1961, in an Address to a Joint Session of Congress, John F Kennedy gives his famous speech; landing men on the moon and returning safely, before the end of the decade.

Kennedy set the lunar-landing goal and was instrumental in accelerating funding and scheduling of the program.

EARLY PROGRAM

Phase one of the program will be with the Saturn I rocket that will propel all ten Saturn I uncrewed development missions.

October 27, 1961; Saturn-Apollo 1 takes place, the first formal test of the Saturn 1s first stage. It is a success.

From this point through till March 28, 1963, three more Saturn Apollo missions are run, culminating in the first orbital test – Saturn-Apollo 5 – on January 29, 1964. From this point through till July 30, 1965, five more missions will be run, coded AS (or Apollo-Saturn) 101-through-105.

The tests are largely successful from a technically perspective, yet a more powerful rocket will be necessary. In late 1965 the focus is shifted towards the improved Saturn 1B which had been added to the program in 1962. With the basics understood and the foundations laid, from this point onward, the Apollo program begins advancing rapidly.

During this period, from 1963 to 1966, another series of tests had taken place at White Sands Missile Range, in tandem with the initial rocket testing. These tests resulted in the development of the launch escape system; an emergency system integrated into the CSM.

There is also strong motivation for the program to roll along without delay, since in 1965, the Soviets have had another victory; during the Voskhod-2 mission, Alexei Leonov becomes the first man to walk in space on March 18, 1965, spending 12 minutes outside the craft, with crew mate Pavel Belyayev inside.

February 26, 1966; The first Apollo test of the new Saturn 1B, mission designation Apollo-Saturn 201. It is the first un-crewed test flight of a production Block 1 rocket of its kind, complete with the Apollo command and service module in Block 1 configuration.

Its largely a success, but experienced SPS under-thrust from helium ingestion and a CM electrical fault that caused rolling on re-entry. Onboard, problems with the CSM are revealed both during flight, and during re-entry. The issues are easily rectified.

July 5, 1966; AS-203, takes flight without a command module. Instead, it tests the capabilities of the S-IV-B, the second stage in the Saturn 1B, and the third stage in Saturn V configuration. The goal was to test how the liquid hydrogen engine would function in weightlessness; the engine would be used to bring the module into proper Earth orbit, and later to boost it into Trans-Lunar Injection. Thus, in the interim, the fuel lines and tank would need to remain at a particular temperature to allow for engine restart, whilst an anti-slosh system would need to function in order to keep correct fuel flow and pressure. The test was a success.

August 25, 1966; AS-202, is equipped with the service module, as well as other necessary tech, fuel cells, navigation and guidance systems. It is essentially a complete production module, save for a few components. The goal is to test most of these systems at higher altitude, and for longer, testing the durability of the entire unit. For the first time, a variety of ejectable cameras will be mounted across the rocket, recording footage of the simulated staging. If successful, the first manned flight will ensue.

The rocket launches, reaching 617.1 nmi (1,142.9km) downrange. Once at altitude, the CSM ran four successful burns of its service propulsion system. Descending, the module then performed a skip re-entry, flying down to 36 n miles, before bleeding speed in an ascension to 44 n miles, then a final descent into the ocean. It is deemed a success. Faith is high, and manned flights will soon commence.

APOLLO UNMANNED FLIGHTS

Apollo 1 (AS-204) – Intended to be first crewed flight; crew (Gus Grissom, Ed White, Roger B. Chaffee) tragically killed in launch pad fire during pre-launch test – January 27, 1967

January 27, 1967; At NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More Launch Complex 34, AS-204 will mark the first time the Apollo program will crew its Saturn 1B. Three crew members will be part of the mission: Command Pilot Gus Grissom, Senior Pilot Ed White, and Pilot Roger B Chaffee. The scheduled launch is February 21st. In the meantime, the crew do rehearsals. January 27 marks one such rehearsal, which includes the entire process up until launch.

The unfuelled Saturn 1B sits on the pad. The crew go through their usual procedure and eventually enter the Command Module. The hatch is closed, locked both mechanically and by the pressure difference inside the cabin.

While everything seems fine, disaster suddenly strikes at 6:31 pm; something seems to spark inside the cabin. The crew are strapped in and look around. The fire spreads extremely rapidly inside the cabin.

The nylon material used inside the cabin is highly flammable and paired with the dense pure oxygen content inside the cabin, it is impossible to put out by hand.

Others try and open the hatch, but the pressure difference has plugged it shut. Before long, all three pilots have died of asphyxia due to inhalation of toxic gases from the fire.

Post-accident reviews found no single cause but a hazardous test configuration: a 100% oxygen cabin at ~16.7 psia, abundant combustible materials (Velcro, nylon netting, foams), wiring and plumbing vulnerabilities, and an inward-opening, multi-piece hatch that prevented rapid egress. The choice of pure oxygen reflected then-current practice and mass/complexity concerns, but in a ground test at elevated pressure it dramatically accelerated fire growth. The precise ignition source was not conclusively identified (electrical arcing is suspected). A related pure-oxygen ground-chamber accident four days later, on 31 January 1967 at Brooks Air Force Base, killed two USAF airmen—underscoring the risks of high-pressure oxygen environments.

Massive public interest in the disaster ensued, and under pressure from congress, crewed Apollo missions were put on hold. The program would, however, continue.

Apollo 4 (AS-501) – First uncrewed Saturn V test flight – November 9, 1967

November 9, 1967; Apollo 4 will be an unmanned mission. However, it will be the first proper test of a new rocket – the Saturn V. The mission sees all stages used; it would feature a Block 1 service module to test Block II changes. It featured a new first stage and second stage; the S-IC and S-II. Finally, it would demonstrate the full capability of the S-IVB restart – which would now be functioning as the third stage in the Saturn V configuration.

The mission lasts 9 hours in total. NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More considers it a complete success; despite its ridiculous complexity, the Saturn V is a powerful and reliable machine, as proven in its first full test. Thanks to the engineers of the new rocket, the mission is an absolute success, and hope in the Apollo program is raised once again.

Apollo 5 (AS-204) – Uncrewed test of Lunar Module in Earth orbit – January 22, 1968

January 22, 1968; After almost a year of setbacks, we have Apollo 5. Once again, it is an unmanned mission; the Lunar Module will be tested in space, launched by a Saturn IB. The plan includes various tests of the modules systems; the ascent and descent engines would be tested, along with its capacity to restart after one firing. Importantly, a test would be done to verify that the ascent stage could be fired while still attached to the descent stage. This would be necessary if the crew – on their descent to the lunar surface – had to abort mission. The Saturn IB would also evaluate the S-IVB and the Instrument Unit in its Saturn V configuration.

That afternoon, the mission began. The Saturn IB worked perfectly, entering the second stage into a perfect orbit. The first test – the firing of the descent engine – was planned for the second orbit. The engine was fired, failing four seconds into the 39 second test, by the Apollo Guidance Computer, which registered a slower than expected orbital speed.

Engineers quickly identified the problem; one of the engine vales – suspected of being leaky – wasn’t armed until its ignition time. This slight delay in propellent flow through this one valve had a slight effect on acceleration during burn time— increasing to noticeable levels given the sheer speed of the module in space.

Flight director Gene Kranz decides to change mission, noting that – in a real-life scenario – the astronauts could easily overcome this problem.

Communication errors are encountered with the craft; however, it is decided that the mission will continue. The team tests the systems manually, completing every burn on the checklist, thus avoiding mission failure.

Shockingly, nearing the end of the flight, the guidance system fails, and the ascent stage spins out of control.

Nevertheless, after a mission of 11 hours and 10 minutes, NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More deems the test a success. A second similar unmanned test was cancelled, with faith high in the lunar module viability in space.

Apollo 6 (AS-502) – Second uncrewed Saturn V test flight – April 4, 1968

April 4, 1968; Apollo 6 begins. It is the second test of the Saturn V. If all goes well, it will also be the final unmanned flight in the Apollo program.

The mission will be the most ambitious yet; using all three stages, the Saturn V will have onboard the service module and lunar test article, a simulated lunar module. The third stage S-IVB is to enter a trans-lunar trajectory. After trans-lunar injection, the Command and Service Module was to perform a short main engine burn a few minutes later to shape a high-apogee, direct-return trajectory—validating the abort mode from translunar coast rather than intentionally overshooting a lunar-orbit insertion.. Then, on its way back, the service modules engine will fire again, accelerating it to speeds simulating a successful return from lunar orbit, with a re-entry angle to match. Thus, in a single 10-hour mission, multiple scenarios could be partially simulated to gather data, and test efficiency of onboard systems. Cameras would be attached to various parts of the rocket, including a 70mm still camera that would take photos of earth’s surface. With a haze-penetrating film and filter, these images would prove important for cartographic and topographic study.

The rocket launches. Problems are encountered; stage 1 receives vibrations from thrust fluctuations. The mission continues, with stage 1 jettison. Stage 2 begins experiencing issues; the second J-2 engine isn’t performing properly. Its performance continues to worsen. At T+412 the Instrument Unit shuts the engine down. Due to a cross wiring, this inadvertently cuts off engine number 3 as well – which was working fine. The Instrument Unit compensates with a longer burn time on the other engines – 58 seconds.

Complications lead the craft into a less-than-ideal orbit. Nevertheless, this is taken advantage of. Mission controllers reposition the S-IVB, testing techniques astronauts could use in such a scenario.

After two orbits, S-IVB prepares for trans-lunar injection, however the engines do not restart.

Flight director Cliff Charlesworth decides to continue the mission with other objectives. The module is flown out to a high apogee, similar to what was done with Apollo 4. Despite system failures, the mission still completes several goals, including the transmission of important data regarding the Van Allen Belts impact on the spacecraft.

Re-entry occurs after 9 hours 57 minutes mission time, with the service module

NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More declares the mission a success. Despite changes to mission profile, many of the initial goals are met. Most importantly, NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More engineers believe that – despite the issues encountered – the viability of the Saturn V, and onboard modules are sufficient to begin manned flight.

Despite little public interest or press coverage due to other competing events at the time, Apollo 6 has quietly guaranteed the viability of the next stage of the Apollo program.

Now will begin manned testing, with more ambitious goals, but at a steady pace, testing the command and service module, and lunar module.

MANNED APOLLO MISSIONS

Apollo 7 – First crewed Apollo flight; Earth orbit – October 11–22, 1968

October 11, 1968; Only a few months have passed, now Apollo 7 will begin. It will be the first manned Apollo mission into space, and the first manned trial of the Saturn 1B. The crew consists of Wally Schirra, Donn Eisele, and Walt Cunningham.

The mission begins, after two minutes the first jettison, as the S-IVB takes over. After one and a half orbits, the command and service module detach from the S-IVB, and simulates the extraction of the Lunar Module – although for this mission, not Lunar Module or Test Article of the kind is on board. Nevertheless, it is important mission practice.

Several hours into the flight, with 80 miles separation, the crew inside the CSM attempt to seek out the S-IVB, in a simulation of a rendezvous, bringing separation back down to 70 feet.

15 hours into the flight, all three crew have head colds – not good – nevertheless they press on.

8 times firing attempts will be made using the service modules engine. Unlike the smooth launch of the Saturn, the small service module jolts the crew back under the power of the engine, pushing them into their seats.

On day 4, a landmark moment; to the hesitation of NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More, a broadcast camera had been placed onboard in a last-minute decision. The crew switch it on, beginning the first TV broadcast of Americans in space.

The mission lasts 10 days 20 hours. Only small problems were encountered; loud fans which the crew switched off, pools of water from sweating coolant lines which the crew vacuumed out, and a scare had happened when both AC busses cut out, requiring a manual reset of the bus breakers.

It has been an important learning curve for the crew; they have noted many small problems – like window fogging and the possibility of fuel cell overheating. The experience also reaffirms the difficulty of even basic tasks in space— Eisele notes that even while using telescope and sextant, unless he could see 40 or 50 stars at once, he would become disoriented and unable to tell exactly where they were looking at in space.

With head colds, the crew debates whether they should have helmets on or off during re-entry. (you wonder why this was ever a question!). The decision is made to keep them on.

Following re-entry, the crew land just over one mile from planned impact point, collected by helicopters from the USS Essex.

The mission is a success and makes modest headlines across the world. It is, however, an important stepping stone, and interest in the space program is once again growing amongst the public.

Apollo 8 – First crewed flight to orbit the Moon – December 21–27, 1968

December 21, 1968; Apollo 8 will mark the first crewed spaceflight to leave earths gravitational sphere of influence, and the first manned flight to reach the moon. This time the crew – consisting of Jim Lovell, William Anders, and Frank Borman – will be aboard the Saturn V.

Launching off, the mission begins. In space, new navigational methods are used by the crews to ensure an accurate orbit. Then, on the second revolution around Earth, trans-lunar injection begins. It is the first time this has been tested properly. At 3 hours 21 minutes, the service module detaches from the S-IVB. Midcourse corrections first occur at 10 hours 55 minutes, a first test for the service propulsion system. AT 68 hours 59 minutes, Apollo 8 passes behind the moon – landmark achievement – and communications temporarily cut out.

A lunar insertion burn was done at 69 hours 8 minutes, slowing the module considerably. 20 hours are spent in lunar orbit, totalling 10 orbits, with the crew sleeplessly at work on various tasks, including vertical stereo and stereo navigation photography, landmarking and site tracking, sextant navigation, and so on. At 89 hours 19 minutes, a 3 minute 29 second trans earth injection burn was commenced, propelling the module back towards home.

On Christmas Eve, the crew broadcasts internationally from space, reading verses from the first chapter of Genesis, before signing off by wishing those on earth a merry Christmas. Unlike Apollo 7, the broadcast quality was of high quality, with high fidelity voice transmission throughout the mission as well.

Re-entering, the mission totalled 6 days 3 hours. An overwhelming success for NASANASA (National Aeronautics and Space Administration): The independent agency of the United States federal government responsible for the civilian spac... More, and a milestone victory for America in the space race.

Apollo 9 – First crewed flight of Lunar Module in Earth orbit – March 3–13, 1969

March 3, 1969; Apollo 9 will mark the second phase of manned testing. Rusty Schweickart, David Scott, and James McDivitt take a Saturn V, this time carrying both the lunar module as well as the command and service module. It will be a more comprehensive simulation of a lunar mission, however due to the added complexity, this will be conducted in low earth orbit.

The mission begins.

Once in orbit, the crew perform several manoeuvres to qualify the Lunar Module, and their ability to properly fly it. The lunar modules ascent and descent propulsion systems are tested, as well as other controls for manual handling.

It also marked America’s first EVA from a Lunar Module and the first in-flight test of the backpack life-support system: Rusty Schweickart stepped outside LM Spider while Dave Scott performed a stand-up EVA at the Command Module hatch to rehearse an external transfer path. No astronaut actually moved between spacecraft; the first true EVA crew transfer had occurred two months earlier on Soyuz 4/5 (January 1969).

However, Apollo 9 will mark other firsts; they will be the first to dock, extract, and operate a manned lunar module in space.

The S-IVB, lunar module, command module and service module would all be tested in a variety of configurations, with various rendezvous and docking manoeuvres. These complex procedures guarantee that all systems – especially the lunar module – will function properly.

Coming in at 10 days 1 hour in length, the mission ended with a re-entry delayed by one revolution, due to heavy seas in the recovery area.

Apollo 10 – Full dress rehearsal for Moon landing; crewed lunar orbit – May 18–26, 1969

May 18, 1969; Apollo 10 will mark the final test of all systems. Like the previous mission, the lunar module and CSM will be tested, this time in lunar orbit. It would be classed as an “F” Type mission, meaning every system and procedure would be simulated short of an actual descent and landing. Initially proposed to include an actual touchdown on the moon, engineers decided against it, noting that a full test of systems had to be done first. The crew will be Thomas Stafford, John Young, and Gene Cernan.

The mission begins. After one and a half revolutions around the earth, trans-lunar injection occurs. Oscillations have occurred, but other than that, the mission goes well.

The accuracy of the injection was so accurate that only one of four planned midcourse corrections was needed.

76 hours in, lunar orbit insertion occurs. The entire lunar landing process is simulated. At the same time, the first colour TV footage of the moon is broadcast.

One problem is encountered during testing; for a short period, the Lunar Module spins out of control, however this is corrected, and testing continues.

After 31 revolutions, many hours of testing, photographs, and data collection, the trans-earth injection begins.

After midcourse correction the command and service module separate, and on May 26 re-entry occurs. The mission is a success, splashing down perfectly, within range of TV cameras set up aboard the USS Princeton.

It comes in at exactly 8 days mission time.

These manned missions in earth and lunar orbit have proven the capability of all major systems; the command and service modules, the lunar module, and the S-IVB itself.

Now, confidence is high in a successful lunar landing being possible.

LUNAR LANDING MISSIONS

Apollo 11 – First Moon landing (Neil Armstrong, Buzz Aldrin) – July 16–24, 1969

On 16 July 1969, Apollo 11 launched from Kennedy Space Center’s Launch Complex 39A at 13:32 UTC, on a Saturn V rocket designated AS-506. The crew were Commander Neil A. Armstrong, Command Module Pilot Michael Collins, and Lunar Module Pilot Edwin E. Aldrin Jr. Their mission was to accomplish the first crewed lunar landing and return safely to Earth, fulfilling the primary national goal set by President JFK in 1961.

The spacecraft consisted of three sections: the Command Module Columbia, which served as the crew’s main living and control space; the Service Module, containing propulsion and support systems; and the Lunar Module Eagle, designed for descent and ascent between lunar orbit and the Moon’s surface. Following trans-lunar injection on the first day of flight, the crew made standard trajectory corrections on their way to the Moon. The spacecraft entered lunar orbit on 19 July after a 76-hour translunar coast.

On 20 July, Armstrong and Aldrin transferred into Eagle and undocked from Columbia, with Collins remaining in solo lunar orbit operations. The Lunar Module began its powered descent to the designated landing site in the southwestern portion of Mare Tranquillitatis. The descent was executed using the descent propulsion system, with final approach involving manual control adjustments to avoid any rough terrain. Eagle touched down at 20:17:40 UTC, landing approximately 6.4 km from the planned target.

Armstrong and Aldrin conducted a single extravehicular activity (EVA) lasting 2 hours, 31 minutes. Activities included the deployment of the Early Apollo Scientific Experiments Package (EASEP), which featured a passive seismometer and a laser ranging retroreflector, as well as the collection of 21.55 kg of lunar rock and soil samples. The American flag was set up, and photos were taken throughout the EVA.

After 21 hours, 36 minutes on the lunar surface, Eagle’s ascent stage lifted off to rendezvous and dock with Columbia on 21 July. The now combined spacecraft departed lunar orbit on 22 July, initiating a trans-Earth injection burn. The mission finished with a successful reentry and splashdown in the Pacific Ocean at 16:50 UTC on 24 July 1969, approximately 1,450 km southwest of Hawaii, where recovery was conducted by the USS Hornet.

Apollo 11 met all primary mission objectives and returned the first lunar material to Earth, providing critical engineering and scientific data for subsequent Apollo missions.

Apollo 12 – Second Moon landing – November 14–24, 1969

Apollo 12 launched again from Kennedy Space Center’s Launch Complex 39A at 16:22 UTC on 14 November 1969 on top of the Saturn V launch vehicle (AS-507). The crew were Commander Charles “Pete” Conrad Jr., Command Module Pilot Richard F. Gordon Jr., and Lunar Module Pilot Alan L. Bean. The mission’s objectives included a precision lunar landing, deployment of an expanded set of scientific instruments, collection of additional lunar samples, and detailed photography of a previous unmanned landing site.

Approximately 36 seconds into flight, the Saturn V was struck twice by lightning, briefly causing power loss in the Command Module Yankee Clipper and setting off multiple warning lights. The crew restored the fuel cell operation by switching to a backup instrumentation power. The vehicle continued to orbit insertion and proceeded to trans-lunar injection without any further problems.

Apollo 12 entered lunar orbit on 18 November after a standard translunar coast and mid-course corrections. On the 19th of November, Conrad and Bean transferred to the Lunar Module Intrepid, undocked from Yankee Clipper, and commenced a powered descent toward the Ocean of Storms (this landing zone was close to the Surveyor 3 spacecraft, which had landed in April 1967). Using visual cues and onboard guidance, Intrepid landed at 06:54 UTC, achieving the program’s first precision landing within about 200 meters of Surveyor 3.

The crew conducted two EVAs totaling 7 hours, 45 minutes. Scientific tasks included deployment of the Apollo Lunar Surface Experiments Package (ALSEP), which had experiments such as a seismometer, magnetometer, and lunar dust detector. Conrad and Bean retrieved components from Surveyor 3, including its television camera, for engineering analysis on Earth. The pair collected 34.35 kg of lunar material, including core and trench samples, providing geologic context from a mare region distinct from Apollo 11’s landing site.

After 31 hours, 31 minutes on the lunar surface, Intrepid’s ascent stage lifted off and rejoined Yankee Clipper in lunar orbit. Gordon had been conducting orbital photography and mapping tasks during their surface exploration. After docking, the Lunar Module ascent stage was jettisoned to impact the Moon, allowing the ALSEP seismometer to record the impact for subsurface studies.

The crew reentered Earth’s atmosphere on 24 November, splashing down at 20:58 UTC in the Pacific Ocean, 800 kilometers southeast of American Samoa, with recovery by USS Hornet.

Apollo 12 proved pinpoint landing capabilities, expanded scientific studies, and demonstrated that surface operations could be conducted in less-than-ideal conditions, such as the overcast skies and adverse weather at launch. These capabilities were important for planning subsequent, more ambitious Apollo missions.

Apollo 13 – Intended third Moon landing; aborted after in-flight accident – April 11–17, 1970

Apollo 13 launched again from Complex 39A at 19:13 UTC on 11 April 1970, aboard the Saturn V (AS-508). The crew were Commander James A. Lovell Jr., Command Module Pilot John L. Swigert Jr., and Lunar Module Pilot Fred W. Haise Jr. The mission’s objective was to conduct the third crewed lunar landing, targeting the Fra Mauro formation, and to set down a suite of scientific experiments and collect surface samples.

Following Earth orbit insertion, the spacecraft performed a trans-lunar injection burn. The Command and Service Module, Odyssey, docked with the Lunar Module Aquarius and separated from the S-IVB stage. The initial flight phase was nominal, with routine mid-course corrections and onboard housekeeping tasks taking place.

On 13 April, approximately 56 hours into the mission and en route to the Moon, the crew were instructed to activate a stirring procedure for the Service Module’s cryogenic oxygen tanks. This action caused an electrical short, resulting in an explosion in oxygen tank number two and subsequent failure of oxygen tank number one (famously re-enacted in the movie Apollo 13). The loss of oxygen supply disabled two of the three fuel cells, drastically reducing the available electrical power. The Command Module’s function was compromised, and the crew had to use the Lunar Module as a “lifeboat”.

Sadly for the crew, the planned lunar landing was aborted. Mission control in Houston devised a new flight plan using the Moon’s gravity for a free-return trajectory, later modified with an engine burn using the Lunar Module’s descent propulsion system to quicken the return. The crew powered down all non-essential systems to conserve energy and water, and improvised carbon dioxide scrubbing using materials on board to adapt Command Module lithium hydroxide canisters to the Lunar Module’s environmental system.

Apollo 13 rounded the Moon on 15 April, passing approximately 254 kilometers above the far side of the moon and course corrections were made to refine the reentry trajectory. The crew reactivated the Command Module shortly before Earth return, managing limited battery reserves and carefully staged power-up sequences (again, brilliantly played out in the film Apollo 13).

On the 17th of April, after jettisoning the Service and Lunar Modules, Odyssey reentered Earth’s atmosphere at 16:53 UTC. Splashdown was in the Pacific Ocean, 6.5 kilometers from the recovery ship USS Iwo Jima. Everyone relieved the astronauts were back home safely.

While Apollo 13 did not achieve its surface objectives as they were never able to land on the moon, the mission validated emergency contingency procedures, demonstrated the adaptability of spacecraft systems (and men) under severe failure conditions, and provided significant operational lessons for spacecraft design and mission planning.

Apollo 14 – Third Moon landing – January 31–February 9, 1971

Apollo 14 launched at 21:03 UTC on 31 January 1971, again on a Saturn V (AS-509). The crew were Commander Alan B. Shepard Jr., Command Module Pilot Stuart A. Roosa, and Lunar Module Pilot Edgar D. Mitchell. The mission’s primary objective was to conduct a crewed landing at the Fra Mauro formation—Apollo 13’s original landing zone—and to deploy and operate the Apollo Lunar Surface Experiments Package (ALSEP) alongside an extended geological sampling program.

Following insertion into Earth orbit, trans-lunar injection was executed without any problem. During the docking of the Command and Service Module Kitty Hawk with the Lunar Module Antares, the probe-and-drogue capture latches failed to engage after multiple attempts. The problem was soon resolved, allowing the mission to proceed to the Moon as planned. Apollo 14 entered lunar orbit on 4 February after the standard translunar coast and mid-course corrections.

On the 5th of February, Shepard and Mitchell transferred to Antares for the descent to the surface of the moon. During the powered descent, a radar acquisition delay required manual intervention. Once resolved, Antares touched down at 09:18 UTC in the Fra Mauro highlands, about 87 meters from the intended target point. Accuracy was getting much better!

Two extravehicular activities (moon walks), totalling 9 hours, 23 minutes, were conducted. The crew deployed the ALSEP, which included experiments such as a seismometer, charged particle detector, and laser retroreflector. They conducted the first use of the Modular Equipment Transporter (MET), a fancy name for a hand-pulled cart used to carrying tools and sample containers, during a planned walk toward Cone Crater. Although the crater rim itself was not reached, samples collected along the route provided valuable geological context for material believed to originate from deeper lunar layers. In total, 42.9 kilograms of lunar rock and soil were returned.

Roosa, remaining in Kitty Hawk, did orbital photography and remote sensing experiments, including multispectral imaging of potential future landing sites. At the completion of surface activities, the Antares ascent stage lifted off to rendezvous and dock with Kitty Hawk on 6 February. As with previous ascent stages, module was commanded to impact the lunar surface to provide a seismic event for ALSEP instruments.

The crew initiated trans-Earth injection on the 6th of February, reentered Earth’s atmosphere on the 9th, and splashed down at 21:05 UTC in the South Pacific Ocean, approximately 1,400 kilometers southeast of American Samoa. Recovery was coordinated by USS New Orleans.

Apollo 14 proved the operational viability of extended time on the moon’s surface, better sampling techniques, and provided geological samples from a region representing material excavated by large impacts—important for understanding lunar crust composition.

Apollo 15 – Fourth Moon landing; first use of Lunar Roving Vehicle – July 26–August 7, 1971

Apollo 15 launched at 13:34 UTC on the 26th of July, 1971, again on a Saturn V (AS-510). The crew were Commander David R. Scott, Command Module Pilot Alfred M. Worden, and Lunar Module Pilot James B. Irwin. This was the first of the Apollo “J” missions, designed for longer lunar surface stays, more scientific objectives, and better mobility through the use of the Lunar Roving Vehicle (LRV).

Following Earth orbit insertion, the trans-lunar injection burn was performed without any problems and the Command and Service Module Endeavour docked successfully with the Lunar Module Falcon – the combined spacecraft proceeded to lunar orbit. Apollo 15 entered lunar orbit on the 29th.

On the 30th, Scott and Irwin transferred to Falcon for descent to the Hadley–Apennine region, selected for its complex geological features including the Apennine Mountains and Hadley Rille. During the descent, precision navigation placed Falcon within approximately 600 meters of the planned landing site! Touchdown was at 22:16 UTC.

Over a 66-hour surface stay, the crew conducted three EVAs totaling 18 hours, 37 minutes. The LRV, a battery-powered, four-wheeled vehicle, was used for the first time, enabling them to drive up to 5 kilometers from the Lunar Module. Scott and Irwin collected 77.3 kilograms of rock and soil samples, including the “Genesis Rock,” a sample of anorthosite believed to represent early lunar crust. The Apollo Lunar Surface Experiments Package (ALSEP) was also deployed, incorporating a heat flow experiment, a laser retroreflector, and a lunar surface magnetometer.

Worden, in Endeavour, did orbital photography and mapping, employing the Scientific Instrument Module (SIM) bay in the Service Module to get multispectral imaging, laser altimetry, and gamma-ray spectrometry. Before reentry, Worden performed the program’s first deep-space EVA during the return trip to retrieve film cassettes from the SIM bay.

The Falcon ascent stage was jettisoned and impacted the Moon to generate seismic data. On 2 August, the crew executed trans-Earth injection. Reentry and splashdown occurred at 20:45 UTC on 7 August in the Pacific Ocean, approximately 530 kilometers north of Hawaii, with recovery by USS Okinawa. Another successful mission.

Apollo 16 – Fifth Moon landing – April 16–27, 1972

Apollo 16 launched from Kennedy Space Center’s Launch Complex at 17:54 UTC on 16 April 1972 aboard the Saturn V rocket, AS-511. The crew were Commander John W. Young, Command Module Pilot Thomas K. Mattingly II, and Lunar Module Pilot Charles M. Duke Jr. This mission was the second of the Apollo “J” series, focused on extended lunar exploration with the Lunar Roving Vehicle (LRV) and expanded scientific experiments. The targeted landing site was the Descartes Highlands, selected to sample highland material thought to be volcanic.

The Command and Service Module Casper successfully docked with the Lunar Module Orion. Apollo 16 entered lunar orbit on the 19th of April after a standard translunar coast and mid-course corrections without any problems. The descent to the surface was delayed by over six hours due to a concern with the Service Module’s main engine gimbal system. After engineering analysis confirmed it was all good to go, Young and Duke went ahead with the landing.

On the 21st, Orion descended to the lunar surface and landed at 02:23 UTC, approximately 270 meters from the landing target in the Descartes Highlands. Over a 71-hour surface stay, the crew conducted three EVAs totaling 20 hours, 14 minutes. The LRV was deployed for trips covering 26.7 kilometers, the longest distance traveled on the lunar surface to that date. Geological investigations included sampling highland breccias and anorthosites, though findings indicated the terrain was formed largely by impact processes rather than volcanism as originally thought.

The Apollo Lunar Surface Experiments Package (ALSEP) was set up, including a cosmic ray detector, seismic profiling experiment, and magnetometer. Other tasks included deploying a far-ultraviolet camera/spectrograph for astronomical and Earth observations from the lunar surface.

While Young and Duke conducted surface operations, Mattingly took photos, did remote sensing, and mapping from the Casper module, focusing on the Descartes region and other high-priority sites. After lunar surface activities were finished, the Orion ascent stage launched on 24 April, rendezvoused with Casper, and it was later commanded to impact the Moon for seismic studies as with the other ascent stages.

On return, Mattingly conducted an EVA to retrieve film cassettes from the Scientific Instrument Module (SIM) bay in the Service Module. Apollo 16 reentered Earth’s atmosphere on 27 April and splashed down at 19:45 UTC in the Pacific Ocean, 350 kilometers southeast of American Samoa, with recovery by USS Ticonderoga.

Apollo 16 expanded the scope of moon geological investigations, they refined LRV driving techniques, and contributed to a broader understanding of lunar crust formation and lunar impact processes.

Apollo 17 – Sixth and final Moon landing – December 7–19, 1972

Apollo 17 launched at 05:33 UTC on 7 December 1972 on a Saturn V (AS-512). The crew were Commander Eugene A. Cernan, Command Module Pilot Ronald E. Evans, and Lunar Module Pilot Harrison H. Schmitt. Schmitt, a geologist, was the first professional scientist-astronaut to participate in a lunar landing. The mission would be the final Apollo lunar surface expedition, and the last crewed mission to travel beyond low Earth orbit in the 20th century.

The targeted landing site was the Taurus–Littrow valley, chosen for its combination of older highland material and younger volcanic deposits. Following Earth orbit insertion, the spacecraft performed the usual trans-lunar injection burn without incident. The Command and Service Module America docked with the Lunar Module Challenger and entered lunar orbit on 10 December.

On the 11th, Cernan and Schmitt undocked in Challenger and commenced powered descent to the Taurus–Littrow landing site. Touchdown occurred at 19:54 UTC, within 200 meters of the intended landing site, and the mission’s surface stay lasted approximately 75 hours, the longest of the Apollo lunar landings.

Three EVAs totaling 22 hours, 4 minutes included the Lunar Roving Vehicle (LRV) driving a total of 35.7 kilometers, the greatest distance traveled by any Apollo crew. Geological investigations included sampling orange-colored soil—later identified as volcanic glass—providing evidence of ancient lunar volcanic activity. In total, 110.5 kilograms of rock and soil were collected, the largest returned by any Apollo mission. The Apollo Lunar Surface Experiments Package (ALSEP) was also set up, incorporating experiments such as a lunar seismic profiling experiment, heat flow experiment, and gravimeter.

Evans, in America, did the usual photography and remote sensing with instruments in the Scientific Instrument Module (SIM) bay. On the return journey, Evans conducted a deep-space EVA to retrieve film canisters from the SIM bay, marking the last EVA conducted in cislunar space.

Reentry and splashdown occurred at 19:25 UTC on 19 December in the Pacific Ocean, approximately 560 kilometers southeast of American Samoa, with capsule recovery by USS Ticonderoga.

Apollo 17 had achieved the most extensive scientific program of the Apollo landings, combining the most distance traveled on the surface, targeted geological sampling, and high-resolution orbital observations. Sadly it marked the end of crewed lunar exploration in the Apollo era.

Apollo Applications / Skylab & Apollo–Soyuz

Skylab 2 (Apollo CSM mission to Skylab) – May 25–June 22, 1973

Skylab 2, as with the other missions, launched from Kennedy Space Center’s Launch Complex at 13:00 UTC on 25 May 1973, aboard a Saturn IB launch vehicle (AS-206). The crew were Commander Charles “Pete” Conrad Jr., Pilot Paul J. Weitz, and Science Pilot Joseph P. Kerwin. It was the first crewed mission to the Skylab orbital workshop, designated Skylab 2 to distinguish it from the uncrewed Skylab launch (Skylab 1) from the 14th of May.

The mission’s objectives were to repair damage sustained to Skylab during launch, activate its systems, and conduct initial scientific operations. The Skylab station had suffered the loss of its micrometeoroid shield and one solar array, resulting in significant overheating and reduced electrical power which needed to be repaired.

Following orbital insertion, the Apollo Command and Service Module (CSM) docked with Skylab on the first attempt. The crew’s first tasks involved deploying a parasol-like thermal shield through a scientific airlock to cool internal temperatures. A spacewalk by Conrad and Kerwin was conducted on the 7th of June to free the remaining jammed solar array. This repair successfully restored enough power generation for the station.

Scientific activities during the 28-day mission included Earth resources photography, solar observations using the Apollo Telescope Mount (ATM), and medical studies on the effects of prolonged weightlessness in space. The crew also evaluated station’s many systems and living arrangements for extended stays on the station.

The mission undocked from Skylab on the 22nd of June, followed by deorbit and reentry of the CSM. Splashdown occurred at 13:49 UTC in the Pacific Ocean, and USS Ticonderoga made the recovery.

Skylab 3 – July 28–September 25, 1973

Skylab 3 launched at 11:10 UTC on 28 July 1973. The crew consisted of Commander Alan L. Bean, Pilot Jack R. Lousma, and Science Pilot Owen K. Garriott. The second crewed mission to the Skylab orbital workshop, it’s mission objectives included extended-duration habitation of Skylab, continued solar and Earth observation using the Apollo Telescope Mount (ATM), Earth resources photography, and a comprehensive program of medical and life sciences experiments to study the physiological effects of prolonged exposure to microgravity.

Shortly after docking with Skylab, the crew discovered a propellant leak in the Apollo Service Module’s Reaction Control System (RCS). This did not endanger the mission but required careful monitoring and procedural adjustments to ensure a safe return.

During their 59-day stay, the crew conducted extensive solar observations, recording solar flares, coronal mass ejections, and sunspot activity. Earth observation work focused on agricultural regions, geological formations, and environmental conditions using both photographic and remote sensing instruments. Life sciences experiments measured cardiovascular performance, muscle strength, and metabolic changes over the extended mission period, providing valuable data for planning future long-duration spaceflights.

Two spacewalks were conducted to replace film in the ATM cameras, perform maintenance, and install new equipment on the station’s exterior. Inside Skylab, the crew maintained and upgraded systems, conducted materials science experiments, and supported medical studies.

The mission undocked on the 25th of September 1973. The Apollo Command Module reentered Earth’s atmosphere and splashed down at 06:20 UTC in the Pacific Ocean, approximately 370 kilometers southwest of San Diego, where recovery was performed by USS New Orleans.

Skylab 3 demonstrated the feasibility of missions approaching two months in space, expanded the scientific studies from the orbital workshop, and further validated operational procedures for managing in-orbit problems.

Skylab 4 – November 16, 1973–February 8, 1974

Skylab 4 launched on the 16th of November 1973 aboard a Saturn IB. The crew were Commander Gerald P. Carr, Pilot William R. Pogue, and Science Pilot Edward G. Gibson. This would be the third and final crewed mission to the Skylab orbital workshop and the longest crewed spaceflight conducted by the United States at that time.

Mission objectives were very much the same as the previous mission, including continued solar observations with the Apollo Telescope Mount (ATM), expanded Earth resources studies, further medical and life sciences research, and long-term evaluation of Skylab’s systems in preparation for potential future use.

After docking with Skylab on the 16th of November, the crew began a mission that would last 84 days. Early in the flight, the crew experienced symptoms of space adaptation syndrome, a form of motion sickness. Adjustments to scheduling and workload were made because of the sickness and the mission proceed as planned.

As with the previous mission, scientific work included extensive solar imaging and spectrographic analysis, capturing significant solar flare activity and other phenomena. Earth observations used photographic and multispectral instruments, focusing on environmental monitoring, land use, and geological surveys. Medical experiments documented cardiovascular, musculoskeletal, and metabolic adaptations to nearly three months of weightlessness, providing critical baseline data for human spaceflight endurance.

Four EVAs were conducted, totaling 22 hours, 13 minutes. Tasks included ATM film replacement, station maintenance, and deployment of additional scientific apparatus. The crew also tested new equipment and procedures intended to extend Skylab’s operational lifespan.

Following completion of the mission’s program, the crew undocked on 8 February 1974, and the Command Module reentered Earth’s atmosphere and splashed down at 15:16 UTC in the Pacific Ocean, and recovered by USS New Orleans.

Skylab 4 set a new duration record for human spaceflight, and provided a comprehensive body of scientific data from its extended program of solar, Earth, and biomedical research.

Apollo–Soyuz Test Project – First joint U.S.–Soviet space mission – July 15–24, 1975

The Apollo–Soyuz Test Project (ASTP) launched on 15 July 1975 as the final flight of the Apollo spacecraft and the concluding mission of the Apollo Program. The U.S. segment launched from Kennedy Space Center’s Launch Complex 39B at 19:50 UTC aboard a Saturn IB launch vehicle designated AS-210. The Apollo crew consisted of Commander Thomas P. Stafford, Command Module Pilot Vance D. Brand, and Docking Module Pilot Donald K. Slayton. The Soviet segment launched earlier the same day at 12:20 UTC from the Baikonur Cosmodrome, carrying cosmonauts Alexei A. Leonov and Valeri N. Kubasov aboard the Soyuz 19 spacecraft.

ASTP’s objectives were to demonstrate international cooperation in crewed spaceflight, test compatible docking systems, and conduct joint scientific experiments in orbit. A specially designed Apollo Docking Module served as an airlock and transfer corridor between the Apollo and Soyuz spacecraft, allowing for differences in atmospheric pressure and environmental systems.

Rendezvous was conducted on the 17th of July, culminating in docking at 16:19 UTC. The spacecraft remained docked for 44 hours, during which time crew members from both nations visited each other’s spacecraft, exchanged commemorative items, and conducted joint experiments in Earth observation, ultraviolet astronomy, and life sciences. The mission also tested a compatible docking system later adopted for international space missions, including Shuttle–Mir and International Space Station operations.

The two spacecraft undocked on 19 July, redocked for further systems testing, and then finally separated to conduct independent mission programs before reentry. The Soyuz crew landed in the Soviet Union on 21 July. The Apollo crew continued in orbit until 24 July, conducting additional experiments before initiating reentry.

The Apollo Command Module reentered Earth’s atmosphere at 21:18 UTC on 24 July 1975, splashing down in the Pacific Ocean 530 kilometers west of Hawaii. Recovery was carried out by USS New Orleans. A malfunction in the reaction control system thrusters during reentry caused toxic nitrogen tetroxide fumes to enter the cabin, briefly incapacitating the crew; all three recovered fully after medical treatment.

The Apollo–Soyuz Test Project achieved its engineering objectives, established protocols for international space docking and cooperation, and marked the symbolic end of the space race era, closing the Apollo Program with a mission focused on collaboration rather than competition.

CONCLUSION

Across twenty flights, Apollo moved stepwise from uncrewed tests to precision landings, then to long-duration operations and international docking. By the time the program closed with Apollo–Soyuz in 1975, it had proven heavy-lift launch, deep-space navigation, rendezvous and docking, surface mobility/travel, and scientific fieldwork on another world! The engineering practices, hardware, and data from these missions became the foundation for Shuttle operations, space-station logistics, and later return-to-the-Moon planning. Apollo’s legacy is a disciplined method: clear objectives, incremental testing, and lessons carried forward—practical groundwork for human deep-space flight.