How Many Times Humans Have Been to the Moon
Fifty-one years ago, the world was united in celebration as they witnessed what was, for many, the single-greatest accomplishment in human history. After more than a decade of concerted effort, the National Aeronautics and Space Administration (NASA) had succeeded in sending the first men to the Moon.
The mission launched from Launch Complex 39A at the Kennedy Space Center in Florida on July 16th, 1969, carrying astronauts Neil Armstrong, Edwin "Buzz" Aldrin, and Michael Collins. After separating from its spent boosters, the Apollo 11 spacecraft flew to the Moon and arrived in orbit about three days later.
On July 20th, the Apollo Lunar Module Eagle separated from the spacecraft and began the descent to the surface. It touched down at precisely 20:17:40 UTC (03:14:40 PST; 06:14:40 EST), at which point Armstrong signaled Houston, "The Eagle has landed."
After several hours of preparation, Armstrong and Aldrin departed the Eagle lander in their spacesuits and descended the ladder to the surface. At 02:56:15 UTC (19:56:15 PST; 22:56:15 EST), six and a half hours after landing, Armstrong stepped off Eagle's footpad and declared: "That's one small step for [a] man, one giant leap for mankind."
This moment in history was the culmination of years' worth of preparation and billions of dollars in investment. It also cost human lives (the Apollo 1 astronauts who died when their cabin caught fire) and effectively capped off the Space Race.
On top of all that, the Moon Landing had many antecedents, where literally dozens of robotics and crewed missions paved the way for the first men to walk on the Moon. After Apollo 11, five more missions and ten more astronauts would go to the Moon before the program concluded.
Five years from now, NASA intends to send astronauts back to the Moon as part of Project Artemis. This mission will involve sending the first woman to the Moon and will be the first time that humans have set foot there since the Apollo 17 mission in 1972.
All of this begs the question: How many missions in total have been sent to explore the Moon? Not just the Apollo missions which involved astronauts, but also the ones conducted by robots? What did we learn from them? And what is planned for the future?
As with everything having to do with space exploration, the first missions to the Moon were conducted exclusively by the United States and the Soviet Union. Consistent with the pace of the "Space Race", the Soviets enjoyed an early lead over their counterparts at NASA.
Between 1958 and 1976, the Soviets sent several orbiters, landers, and rovers to the Moon as part of their Luna, Zond, and Lunakohd programs. The first two missions (Luna 1 and 2) were sent in January and September 1959, respectively.
Both missions were intended to impact uncrewed spacecraft on the Moon. While the first mission suffered a malfunction and ended up in orbit around the Moon, the second successfully impacted on the surface.
Some of the most notable of these missions include the Luna 3, 9, and 16 missions that launched in 1959, 1966, and 1970, respectively. Together, these missions were the first to photograph the far side of the Moon, make a soft landing on the Moon, and conduct the first robotic sample-return mission from the Moon.
In the ensuing years, Luna 20 and 24 (1972 and 1976) also brought Moon rocks back to Earth for analysis. And 1976, the Soviets shifted their focus to Venus (the Venera Program) and the development of space stations (more on that below).
Similarly, the Lunokhod 1 mission (1970) was the first rover to land on the Moon or any other celestial body. The second mission, Lunokhod 2, also landed a rover on the Moon, took television images of the surface, and performed a number of scientific measurements.
In the U.S., NASA began exploring the lunar surface well in advance of any crewed missions. These included the Moon Ranger (1964-65), Lunar Orbiter (1966-67), and Surveyor (1966-68) programs, which would gather data on the geography and topology of the lunar surface.
These studies yielded valuable information that allowed NASA to select landing sites for its crewed lunar missions. These would be conducted as part of the Apollo program, which was unveiled in 1961.
The Race to the Moon:
Having sent the first humans to space and explored the lunar surface with robotic missions, the US and Soviet space programs began taking steps to send the first astronauts to the Moon.
Not only was this the next logical step in human space exploration; in the context of the Cold War and the "Space Race", it was seen as an accomplishment that was vital to both national interests and security.
The importance of this was illustrated by President John F. Kennedy in a speech titled "Special Message to the Congress on Urgent National Needs" which was delivered on May 25th, 1961. In the course of the speech, Kennedy said the following:
"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. We propose to accelerate the development of the appropriate lunar spacecraft.
"We propose to develop alternate liquid and solid fuel boosters, much larger than any now being developed, until certain which is superior. We propose additional funds for other engine development and for unmanned explorations – explorations which are particularly important for one purpose which this nation will never overlook: the survival of the man who first makes this daring flight. But in a very real sense, it will not be one man going to the Moon – if we make this judgment affirmatively, it will be an entire nation. For all of us must work to put him there."
These goals and the purpose behind them were further outlined by Kennedy during his famous "We choose to go to the Moon!" speech, delivered at Rice University on Sept. 12th, 1962.
Raising the issue of how the US had been at the forefront of technological development and progress in the past, Kennedy stressed the need for the country to set its sights on the challenge of going to the Moon, and of being the first country to do so:
"For the eyes of the world now look into space, to the moon and to the planets beyond, and we have vowed that we shall not see it governed by a hostile flag of conquest, but by a banner of freedom and peace. We have vowed that we shall not see space filled with weapons of mass destruction, but with instruments of knowledge and understanding. [...]
"There is no strife, no prejudice, no national conflict in outer space as yet. Its hazards are hostile to us all. Its conquest deserves the best of all mankind, and its opportunity for peaceful cooperation may never come again. But why, some say, the Moon? Why choose this as our goal? And they may well ask why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas?
"We choose to go to the Moon. We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too."
The first crewed Apollo missions began in January of 1967 with Apollo 1, which resulted in tragedy when the spacecraft experienced an electrical fire during a test run. The capsule was destroyed, and the crew of three (Virgil I. “Gus” Grissom, Edward H. White II, and Roger B. Chaffee) all died.
Missions resumed in October of 1968 with Apollo 7, in which the spacecraft conducted simulated rendezvous and docking procedures, which would be required to extract the Lunar Module (LM) for future Moon landings.
The next crewed mission, Apollo 8, was the first to send astronauts around the Moon, in December of 1968. This was followed by Apollo 9 and 10 in March and May of 1969, respectively. These missions practiced the docking maneuvers that were needed for the Moon Landing.
On July 20th, 1969, the long-awaited Moon Landing was made by the Apollo 11 mission, and astronauts Neil Armstrong and Buzz Aldrin became the first men to walk on the Moon. Between 1969 and 1972, five subsequent Apollo missions landed on the surface of the Moon before the program ended.
Including Apollo 11, all of these missions (with the exception of Apollo 13, which was forced to abort its lunar landing) obtained samples of Moon rocks and conducted scientific experiments on the surface.
From Getting to Space to Staying in Space:
With the success of the Apollo program and the changing budget environment of the 1970s, both NASA and their Russian counterparts began to shift their focus onto new, long-term goals.
While Russia had officially ceded the race to the Moon by 1963, they continued to develop heavy-launch vehicles such as the Proton and L1 rockets, and spacecraft like the Zond and Soyuz 7K-LOK (which included the LK lander).
However, by the mid-to-late 1970s, the focus of both organizations shifted from 'getting there first' to developing the necessary technologies that would allow for a long-term human presence in space. They also began looking for ways to make space exploration and research more cost-effective.
In short, their focus shifted to the development of space engines and reusable spacecraft. For the Soviets, this bore fruit in the form of the Salyut space stations, six of which were successfully deployed to low-Earth orbit (LEO) between 1971 and 1986.
While two of these stations were used for military reconnaissance (using the civilian program as cover), the majority were research stations that conducted studies into the problems of living in space.
The lessons learned were incorporated into the Soviet space program's crowning achievement, the Mir space station. This space station was in continuous operation between 1986 and 2001, when it was deorbited and its remains fell into the South Pacific.
For NASA, the development of space stations achieved fruition with the deployment of Skylab. This station orbited Earth from 1973 to 1979 and was the site of vital research, including studies in materials processing in microgravity, Earth observations, solar astronomy, and the effects of spending long periods in space.
The combined lessons of the Soviet/Russian and American space station programs informed the creation of the International Space Station. Construction of the station in orbit began in 1998 and it has been in continuous operation since November of 2000.
Both the United States and the Soviet Union/Russia also pursued parallel programs to develop reusable space planes. For NASA, this led to the creation of the Space Shuttle, which consisted of a reusable orbital vehicle that was launched into space using expendable boosters and an external fuel tank.
The Soviets developed a similar design known as the Buran, which also consisted of a reusable orbital vehicle, along with the Energia super rocket. This latter element consisted of an external fuel tank and four strap-on boosters. Following the disintegration of the Soviet Union in 1991, the Buran program was canceled.
In total, NASA constructed five orbital vehicles, which included the Space Shuttles Columbia, Challenger, Discovery, Atlantis, and Endeavor. Two of these were lost in operation - the Challenger exploded on launch in 1986 and the Columbia broke up on re-entry in 2003 - while the remaining three were retired in 2011.
Between 1981 and 2011, the Space Shuttle fleet conducted 134 launches and was essential to the deployment of satellites, several orbiting observatories (like the Hubble Space Telescope), and many of the components used to build the ISS.
These developments helped lay the groundwork for the modern era of space exploration, which is characterized by international cooperation, the search for more cost-effective methods of space exploration, and the dream of establishing far-reaching, sustainable human space exploration.
More Countries Join the Lunar Club:
One of the clearest indications that space exploration has become an international affair since the Apollo era is the way that more nations have been sending missions to the Moon.
In 1990, the Japanese Aerospace Exploration Agency (JAXA) visited the Moon with the Hiten spacecraft, becoming the third country to place an object in orbit around the Moon. The spacecraft also deployed the Hagoromo to gather more information from its lunar orbit, but the transmitter failed.
In September of 2007, Japan launched the SELenological and ENgineering Explorer (SELENE) spacecraft - aka. Kaguya (named for a moon-born princess in Japanese folklore). During the year and eight months that it orbited the Moon, the mission gathered vital data on the Moon's topography, chemical, and magnetic environment.
The mission also made the first optical observations of the famous Shackleton crater at the lunar south pole. Known for being permanently shaded, and for possibly containing large amounts of water ice, this crater is being considered by many space agencies as a possible location for a permanent Moonbase.
The Indian Space Research Organisation (ISRO) has also joined the lunar club in recent years. This began in October of 2008 with the launch of Chandrayaan-1, an uncrewed lunar orbiter. The probe was originally intended to orbit and map the Moon for two years but crashed on the surface after 10 months.
The mission also included the Moon Impact Probe, which struck the south pole of the Moon in a controlled manner on November 14th, 2008, making India the fourth country to land on the lunar surface. The purpose of the probe was to eject material from beneath the surface for analysis. Among other things, this revealed evidence for the presence of water in the lunar soil.
On July 22nd, 2019, the ISRO launched their second lunar exploration spacecraft (Chandrayaan-2), which is scheduled to deploy a lander and a rover to the lunar surface on September 7th. This will make India the fourth nation to achieve a soft landing on the Moon.
The Chinese National Space Agency (CNSA) has also conducted some very impressive lunar missions in recent years. In 2003, they launched the Chinese Lunar Exploration Program - aka. the Chang'e program, named after the Chinese Moon goddess.
This program has consisted of a series of increasingly-sophisticated robotic missions exploring the Moon in preparation for an eventual crewed mission. The program is designed to occur in three phases.
For Phase I, two robotic spacecraft were to be sent to study the Moon from orbit. Phase II would entail soft landers and rovers landing on the surface to explore and conduct experiments.
Phase III would involve additional landers and rovers that would conduct sample-return missions with Earth. The fourth and final phase calls for the creation of a robotic research station near the Moon's south pole.
The program's first lunar orbiter (Chang'e 1) was launched in 2007, which made China the fifth nation to successfully orbit the Moon and map its surface. This was followed by the launch of the Chang'e 2 in 2010, which mapped the Moon in greater detail. This concluded Phase I of the Chang'e program.
This was followed by Phase II, which began with the Chang'e 3 lander in 2013. This mission deployed the Yutu ('Jade Rabbit') rover on the lunar surface, which explored the lunar surface and conducted ultra-violet astronomy experiments and studies of Earth's plasmasphere.
The Chang'e 4 lander, reached the far side of the Moon in January of 2019. The Yutu 2 rover was then deployed to explore the South Pole-Aitken Basin, a location that is thought to contain supplies of water ice and is considered a possible location for a lunar outpost.
The lander also carried the Lunar Micro Ecosystem (LME) experiment, a metal cylinder containing seeds and insect eggs designed to test the effects of lunar gravity on living creatures. The orbiter component of the mission also tested the ability to relay communications from the far side of the Moon.
These experiments are designed, in part, to determine whether long-term human missions to the Moon (which include an outpost) are possible. The third phase will conclude with another sample-return mission conducted by the Chang'e 5 lander and orbiter, which launched on Nov. 23rd, 2020 atop a Long March 5 rocket.
In 2003, the European Space Agency (ESA) launched the SMART-1 probe, which conducted a lunar flight designed to test cutting-edge ion propulsion technology. In 2016, during the annual Council of Ministers, the ESA announced plans to create the International Moon Village - a cooperative endeavor that would act as a spiritual successor to the ISS.
In February of 2019, the first Israeli and privately-funded lunar mission (Beresheet) launched from Cape Canaveral, Florida, atop a Falcon 9 rocket. While the lander malfunctioned and crashed on the lunar surface, it managed to enter lunar orbit beforehand - a historic first for the nation.
The achievements of these national space agencies have helped advance lunar exploration considerably. In the future, the prospect of international collaborations between many or all of them will be key to taking lunar exploration to the next level.
Returning to the Moon to Stay:
In 2005, NASA and the US government began making plans to take the next bold leap in space exploration. Addressing the fact that all missions since the Apollo era had been to Low-Earth Orbit, the focus of their efforts was on taking the next great leap.
These goals were laid out by then-NASA Administrator Sean O'Keefe in a 2004 study titled "Vision for Space Exploration", which called for the following steps to be taken:
- Develop a new Crew Exploration Vehicle (CEV) by 2008
- Explore the Moon with robotic spacecraft by 2008
- Complete the International Space Station by 2010
- Retire the Space Shuttle by 2010
- Conduct its first human spaceflight mission by 2014
- Crewed lunar missions by 2020
- Develop new technologies for the exploration of Mars and beyond
- Explore Mars and other destinations with robotic and crewed missions
The following year, O'Keefe's successor, Michael D. Griffin, further refined these goals with the Exploration Systems Architecture Study, issued in November of 2005. These goals were formalized with the NASA Authorization Act of 2005, which directed NASA to:
"[D]evelop a sustained human presence on the Moon, including a robust precursor program to promote exploration, science, commerce and US preeminence in space, and as a stepping stone to future exploration of Mars and other destinations."
This led to the creation of the Constellation Program, a three-step endeavor that envisioned the creation of a new class of CEV and a heavy-launch rocket that would allow for the "completion of the International Space Station", a "return to the Moon no later than 2020", and an eventual mission to Mars.
At the heart of the program was a new class of heavy-launch vehicle known as the Ares rocket family. This consisted of the Ares I, a two-stage rocket that would launch the Orion into space, and the Ares V that would launch heavy payloads.
In February of 2010, the program was canceled due to the changing budget environment in the wake of the Great Recession of 2008-09. By October of 2010, then-President Obama signed the NASA Authorization Act of 2010, which effectively greenlighted NASA's "Journey to Mars".
In accordance with this Act, NASA was directed to take all the necessary steps to develop:
"[S]pace technologies such as advanced propulsion, propellant depots, in situ resource utilization, and robotic pay-loads or capabilities that enable human missions beyond low- Earth orbit ultimately leading to Mars."
These included the Space Launch System (SLS), a modified version of the Ares V that would be used to launch spacecraft and payloads to LEO, the Moon, and Mars. It also included the Orion Multi-Purpose Crew Vehicle (MPCV), which had evolved from the earlier CEV designs.
The plan also called for the construction of the Lunar Orbital Platform-Gateway (LOP-G) - also known as the Lunar Gateway - and the Deep Space Transport. Whereas the former would allow for missions to return to the Moon via a reusable orbital lander, the latter would allow for missions to deep-space destinations like Mars.
In December of 2017, the focus of NASA's efforts shifted once again, thanks to the signing of Space Policy Directive-1 (SPD-1) by the Trump administration. This called for the reestablishment of the National Space Council (NSC) and for NASA to:
“[L]ead an innovative and sustainable program of exploration with commercial and international partners to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities.”
In accordance with SPD-1, NASA was once again to prioritize sending astronauts back to the Moon. By March of 2019, Vice President Mike Pence directed NASA to expedite their efforts and land the first astronauts of the post-Apollo era on the Moon by 2024.
These efforts are now officially known as Project Artemis, named after the twin sister of Apollo in Greek mythology. Due to their expedited timetable, NASA now plans to execute their return to the Moon with three missions.
The first mission (Artemis I) will be a test flight that will take an uncrewed Orion capsule around the Moon. This mission is scheduled to launch by November of 2021 and deliver 13 CubeSats to orbit. Artemis II is to follow in August of 2023 and will involve a crewed Orion conducting another flyby of the Moon.
By 2024, the Artemis III mission will send a crew of up to four astronauts to the South Pole-Aitken Basin in the Moon's southern polar region. Two crew members, "the first woman and the next man," will land on the surface using a lunar lander, to the Moon, conduct four spacewalks, a variety of scientific observations, and take samples of water ice.
Beyond Artemis III, NASA plans to use the SLS and Orion spacecraft to deploy permanent infrastructure to the Moon by the late 2020s. This includes the Artemis Gateway, an orbital habitat that will allow for long-term missions to the surface.
Initially, it will consist of two modules: the Power and Propulsion Element (PPE), developed by Maxar Technologies, and the Habitation and Logistics Outpost (HALO) developed by Northrop Grumman. Over time, additional modules will be provided by the ESA, JAXA, and Roscosmos.
NASA also plans to build the Artemis Basecamp on the lunar surface that would consist of three main modules: the Foundational Surface Habitat (FSH), the Habitable Mobility Platform (HMP), and the Lunar Terrain Vehicle (LTV). NASA has also contracted with several commercial partners to develop a Human Landing System (HLS) and deliver payloads to the surface.
Between NASA, Roscosmos, the ESA, India, and China, lunar exploration is expected to grow by leaps and bounds in the next decade. Beyond NASA's hopes to build the Gateway and land astronauts around the Moon's southern polar region by 2024, and the ESA's International Moon Village, there is no shortage of ambitious projects.
For example, in 2015, Roscosmos stated that Russia plans to place an astronaut on the Moon by 2030. To achieve this, Roscosmos has dusted off its plans for the Luna-Glob program and will send a lunar lander to the South Pole (Luna 25) in October of 2021.
This will be followed by the Luna 26 in 2024, a lunar orbiter that will study the southern poler region and act as a communications relay for Luna 27 - a lander that will launch in 2025 - and other Russian elements in the region.
Plans also exist for a joint NASA-Roscosmos mission that would see Russian cosmonauts sent to lunar orbit in 2025. And, like NASA, Russia also hopes to build an orbital habitat - the Lunar Orbital Station - after 2030, which will facilitate long-term missions to the surface.
China also intends to send three more missions to the Moon (between 2023 and 2027) as part of phase four of its lunar exploration program. This will consist of sending three landers, orbiter, and rover missions that will investigate the South-Pole Aitken Basin in more detail.
In addition to mapping its topography, this phase will assess the Basin's level of resources and obtain samples for analysis. This phase could also include a 3D-printing experiment that will use lunar regolith to build a structure and a sealed ecosystem experiment.
According to statements made by the CNSA, China hopes to conduct crewed missions to the South-Pole Aitken Basin by the 2030s that will culminate in the creation of a lunar outpost - called Yuegong-1 ("lunar palace").
By 2024, India hopes to launch the third mission in its robotic lunar exploration program - Chandrayaan-3. This will be a joint-mission with JAXA and will likely involve a lander-rover mission that will collect and analyze lunar material, and possibly return samples to Earth. Beyond that, India will likely attempt to conduct crewed lunar missions as well.
JAXA plans to send their Smart Lander for Investigating Moon (SLIM) in January of 2022 to attempt their first soft landing on the Moon. The Korea Aerospace Research Institute (KARI) will send their Korean Pathfinder Lunar Orbiter (KPLO) missing by August of 2022. The United Arab Emirates (UAE) space agency will send the country's first lunar rover (Rashid) to the Moon in 2024.
In the next 20 years, commercial aerospace companies are also hoping to establish a presence on the Moon. Between SpaceX, Blue Origin, and other ventures, everything from payload delivery to lunar tourism is expected to become a regular occurrence.
As Earth's closest celestial neighbor, the Moon has always had a special place in our hearts, our folklore, and our mythology. The same holds true of our goals for space exploration and our aspirations for the future exploration of the solar system.
By the 2030s, it's entirely possible that a human presence will be established on the Moon in the form of rotating research teams, similar to the ISS. By 2040 and 2050, it's even possible that humans will be living on the Moon.
Who knows? By the end of the 21st century, the Moon could have everything from human settlements to its own economy built on ore, water, and helium-3 extraction, as well as tourism, agriculture, and even real estate. There could even be a new generation of permanent Moon residents, perhaps known as "Selenians" (or possibly "Loonies").
In other words, we're going back to the Moon. And this time, we intend to stay!
Visuals provided courtesy of Visme. Be sure to check out the full infographic "50 Years After the Moon Landing, What Is the Future of Space Exploration?"
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