Why does it take us so long to return to the moon?

July 21st^stIn 1969, Neil Armstrong and Buzz Aldrin, the first humans to set foot on the Moon, left the Lunar Lander module and began to find their bearings on the surface of the Moon. This mission, Apollo 11, would mark a turning point in the history of humanity and would forever be remembered as the crowning event of the space race.

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Between 1969 and 1972, five other Apollo missions would have placed astronauts on the surface of the moon, each conducting research and experiments on the moon (including the recovery of rocks of the Moon for study). However, after the sixth mission that saw astronauts land on the lunar surface (Apollo 17), the program was interrupted.

Over the next five decades, all missions mounted by NASA and its main rival – Roscosmos, the Russian Federal Space Agency – would be focused on low-Earth-orbit (LEO) operations. But in the mid-2000s, NASA began taking the necessary steps to bring us back to the moon.

In recent years, these steps have resulted in NASA's "Journey to Mars" project and its renewed mission projects on the lunar surface. Although much remains to be done before either can take place, NASA believes it will be able to send astronauts back to the moon no later than the end of the next decade.

Which raises the question: why does it take us so long to return to the moon? If NASA is able to send crewed missions to the lunar surface by 2029 at the latest, it will be sixty years since the moon landed (and fifty-seven years since the last mission Apollo sent astronauts to the moon). So, why does the intermission incredibly long?

Well, to answer that question, some very important questions need to be addressed first. First of all, what did it take to get to the moon? What did we learn from the first "Moonshot"? And, just as importantly, what will be the next big jump in space exploration – the proposed "Journey to Mars"?

The challenges of making a "Moonshot":

September 12^th1962, US President John F. Kennedy makes his famous "We choose to go to the moonThis speech aimed to encourage American support for the Apollo program, launched two years earlier.

In addition to highlighting the benefits that the program would entail, Kennedy pointed out that one of the main reasons for conducting a lunar program was the challenge that it represented. As he said:

"We choose to go to the moon.We chose to go to the moon during this decade and do the other tasks not because they are easy, but because they are not easy. they are difficult because this goal will serve to organize and measure the best of our energies and our skills, because this challenge is one of them, that we are willing to accept, that we do not do not want to differ and that we intend to win. "

The challenge, quite simply, was monumental. In the early 1960s, NASA was able to send astronauts into orbit. Mercury Project, which was NASA's first effort to send astronauts into space, had ended Gemini Project was well underway. As part of Mercury, six American astronauts had been sent into orbit, culminating in the 22 orbits of Gordon Cooper's planet.

In 1966, ten crews of two astronauts were sent to Low Earth Orbit (LEO) as part of Gemini. However, to send astronauts to the moon, NASA had to invest in a whole new breed of rockets and spaceships. The one-stage Redstone and Atlas rockets and the two-story Titan II rockets were well suited for sending astronauts into orbit.

But to reach the Moon, NASA would need a heavy launcher and a spacecraft capable of both reaching the lunar surface and bringing astronauts back to Earth. To this end, Saturn rocket family has been developed and for crewed missions, nothing less than the Saturn V would.

This three-stage launcher was at the time the world's most powerful rocket capable of lifting 140,000 kg (310,000 lb) LEO and 48,600 kg (107,100 lb) Trans-Lunar Injection (TLI). No rocket has been able to match its performance since, not before Space launch system (SLS) and SpaceX Spatialship (aka BFR) are unveiled.

Similarly, a spacecraft of three modules was needed to bring the astronauts to the moon and then bring them home. These include the Control Module (CM), the Service Module (SM) and the Apollo Lunar Module (ALM). The CM would hold the crew of four, the SM would propel the entire spacecraft and the ALM system would allow two of the three astronauts to land on the Moon and then return to the lunar orbit.

The ALM also came in two sections: the ascent phase and the descent phase. As the names suggest, the descent phase was what allowed the two-person crew to descend to the lunar surface and was the place where the astronauts stored their equipment. The ascent phase is where the crew compartment was, allowing the astronauts to leave.

The plan was relatively simple. The Saturn V would be launched from Earth. The first stage would propel the rocket to orbital speed before being thrown and ignited in the Earth's atmosphere. At this point, the second leg would ignite, bring the rocket and spacecraft to an altitude of 185 km, and then be thrown into Earth orbit.

The third and final step then ignited the spacecraft and gave it a translucent trajectory (speed of 24,500 km / h) before finally being scrapped. At this point, the combined Command and Service Modules (CSM) would take the crew of three astronauts and ALM to the moon.

Once in the lunar orbit, ALM would separate from the CSM and bring two astronauts to the surface where they would conduct scientific operations. Once the astronauts were finished, they boarded the ALM and the climb phase took off (leaving the descent phase behind) and made rendezvous to the CSM in orbit.

The CSM would then break the orbit and insert the probe into a transearth injection, bringing them back to their home. Once they reached Earth, the CM and SM would separate, the CM would land in the ocean and the crew would be recovered. Mission accomplished.

All this equipment, intense training and technical expertise were needed to send astronauts to the moon. This investment would result in the creation of thousands of jobs, invaluable experience for astronauts, engineers and support teams, many commercial applications and scientific breakthroughs, as well as a cultural impact that is still being made. feel today.

So, why does it take us so long to come back? The challenges were certainly great, but are they somehow beyond the current generation, unlike our ancestors? The simple answer is no, but with some reservations. To answer the question effectively, we must consider an important aspect of the Apollo program that is often overlooked.

What was the effectiveness of the Apollo program?

Of course, it is impossible to put a price tag on the achievements of the Apollo program. It is also undeniable that the scientific and commercial benefits were immense and that its impact on the hearts and minds of generations of people is immeasurable.

However, he is possible to put a price tag on the Apollo program itself, and this has been done. According to 1974 Hearings on NASA's AuthorizationApollo missions cost US taxpayers $ 25.4 billion, an adjusted amount of inflation of nearly $ 144 billion today.

But of course, you have to take into account the costs of Mercury Project and Gemini Projectbecause they were key stepping stones for Apollo. When you do this, you get a grand total of about $ 159 billion. In other words, it took $ 22 billion to set up a workspace program that could place astronauts in orbit and prepare them to go to the moon.

At the same time, sending them to the moon costs six and a half times more than the two previous projects combined. Where did all this money go?

Well, this has been used to develop rockets and spaceships powerful enough to bring astronauts (and all their equipment and supplies) to the moon in one shot. This, as well as the amount of fuel required to do so, meant that the launchers had to be very big and powerful, and therefore very expensive.

In addition, launchers and the spacecraft that allowed astronauts to get to the moon, land on it, conduct operations on the surface, and then return home were entirely expendable. Once the three floors of the Saturn V rockets exhausted, they either fell into the ocean or became space debris in orbit.

The same goes for the command, service and lunar modules, which found themselves on the lunar surface, in space or in the ocean at the end of each mission. No mission architecture was designed to be reused, which means everything was designed to be used and then discarded.

And by the end of the Apollo program, there was nothing sustainable or reusable between the Earth and the Moon. No space stations, no refueling depots and no lunar base – nothing that would allow new missions to the Moon in the near future.

The Saturn Vs were decommissioned and all the infrastructure put in place to build and maintain them (as well as all other aspects of the Apollo program) was decommissioned.

In short, the Apollo program was not effective, not long term. But of course, it was not supposed to be. For NASA, the very purpose of the program was to go to the moon as quickly as possible, not to mention the fact that it beat the Russians. Speed ​​was essential, not a slow, gradual accumulation that would eventually lead to the lunar surface.

If NASA had sought to create a sustainable, efficient and long-term way to reach the moon, it would have adopted a phased approach that would probably have taken decades. To do this, it would probably be necessary to use one or two-stage rockets to build a space station in low Earth orbit.

This station would then serve as a starting point and arrival to a spacecraft to transport astronauts to and from the Moon. In lunar orbit, a second space station should be built to allow the spacecraft to meet and transfer the astronauts into a lunar module. This module would then bring them to the surface and go back to orbit.

If this sounds familiar to you, it's probably because it looks a lot like what Arthur C. Clarke had envisioned in Stanley Kubrick. 2001: The Space Odyssey. Published in 1968, about a year before Moon's landing, this vision of the future was based on Clarke's vast knowledge of physics and space exploration. It was therefore logical from the scientific point of view.

However, given the historical context in which the Apollo program took place, it is unreasonable to expect that they have chosen to take a slow and steady approach. Even if it meant that there would not have been so much intertwining between the first landing of the Moon and the next, the first Moon Landing would probably not have occurred before the years 1980.

In any case, once the Apollo program was completed, NASA and its Russian counterparts were forced to scale down and start thinking about long-term, profitable goals. The United States had indeed won the "Space Race", it was now time to focus on the next steps.

This was achieved by significantly reducing the costs of launching payloads and crews into space, and developing technologies for a long-term human presence in space. These included the development of space vehicles and reusable space stations.

For NASA, these efforts paid off with the creation of the space shuttle, consisting of two powerful thrusters, an external fuel tank and the orbital vehicle (OV). For the Russians, it bore fruit in the form of the Buran Spacecraft, which was closely modeled on the Space Shuttle.

In terms of space stations, Roscosmos has taken a quick lead with the launch of the six Salyut space stations (1971 to 1986) and Mir (1986-1996). Meanwhile, NASA made significant progress with the deployment of Skylab (1973-1979). In the 1990s, the two organizations joined forces with other space agencies to create the International Space Station (ISS).

These developments, among others, would play an important role in helping NASA reach the stage where bold new initiatives could be considered. These include current plans to send astronauts back to the moon and Mars.

When will we be able to make the next big leap?

Plans for the "Journey to Mars" really began with the death of NASA's 2010 Authorization Act and the US National Space Policy published the same year. This act reaffirmed NASA's commitment to the International Space Station, partnerships with commercial entities and the development of essential space exploration technologies.

Most importantly, this law also directed NASA to take the necessary steps to create the mission architecture that would allow the first crewed missions to Mars over the next two decades. These steps have been divided into three phases:

Phase I: Reliant Earth

This phase includes the restoration of the domestic launch capability in the United States. With the withdrawal of the space shuttle in 2011, NASA depended on Roscosmos to send astronauts into the ISS using their proven Soyuz rockets. NASA has relied on commercial launch providers such as United Launch Alliance (ULA), Orbital ATK, SpaceX and others.

But to send astronauts into distant spaces, NASA needed a new class of heavy launchers capable of competing with the Saturn V. Space launch system (SLS), a huge rocket designed (and in the making) by Boeing, ULA, Northrop Grumman and Aerojet Rocketdyne.

The design combines elements of the Space Shuttle (solid rocket propellants) with the main scene of the Constellation program rocket designs (a modified version of the Space Shuttle's outer tank). With a total thrust of 32,000 kilonewtons (7,200,000 pounds), the SLS will be the most powerful rocket in history.

NASA also needed a new crew exploration vehicle that could carry crews of six astronauts and many equipment. This was done with the Orion All-Wheel Crew Vehicle (MPCV), a joint project of NASA and the European Space Agency (ESA), designed by Lockheed Martin and Airbus.

At present, two Orion capsules have been finalized and will be sent to space over the next few years. Meanwhile, NASA is still studying the effect of long-duration space flight on the health and physiology of astronauts (which includes the Twin study).

At the same time, they are studying various technologies that will come into play, such as additive manufacturing (3D printing), advanced communication systems, environmental control systems and life sustainment systems for Mars and solar electric propulsion (SEP) – a form of ionic propulsion.

Which brings us to …

Phase II: Ground of test

Once the SLS and the Orion spacecraft are ready and ready to operate, NASA will begin organizing a series of missions to see how they are doing in space. Initially, it was planned to conduct a mission on a near-Earth asteroid (NEA) during the 2020s to validate the spacecraft in order to develop the necessary expertise as an astronaut.

Known as the Asteroidal Robotic Rerouting Mission (ARRM), it would send a robotic spacecraft to capture and tow a NEA in lunar orbit. This was to be followed by a crewed Orion spacecraft sent to explore the asteroid and return samples to Earth.

However, this plan was canceled when the White House 1 Space Policy Directive was released in December 2017. Instead, the Orion and SLS systems would be tested through a series of missions to the White House. the cis-lunar space. The first, named Exploration Mission-1 (EM-1), is scheduled for June 2020.

This unprepared mission will see the Orion capsule be launched by the SLS for the first time and send it on a journey around the Moon. Exploration mission 2 (EM-2), scheduled for June 2022, will be the first crewed mission of the Orion and will also involve the flying spacecraft around the Moon.

In 2024, Exploration Mission 3 will involve a crewed Orion flying to the Moon to deliver the first of several pieces of the Lunar orbital platform (LOP-G) – the next big element in the overall architecture of the mission. Formerly known as Deepspace Gateway, the LOP-G is an international project led by NASA to create a solar-powered housing module in orbit of the Moon.

This station will gravitate around the moon every six days and will lead scientific operations on the lunar surface. This will include sample return missions, similar to those conducted by Apollo astronauts, as well as tests involving vehicles and equipment for Mars.

Surface displacements will be facilitated through the addition of a reusable lunar lander. These missions could last up to two weeks before having to return to the bridge, without maintenance or refueling on the surface. The completion of the station is scheduled for the mid-2020s. It is an integral part of NASA's plan to renew lunar exploration.

The station will also serve as a hub for other space agencies to mount lunar missions, as well as commercial activities on the moon (ie lunar tourism). It will also play a vital role in creating a permanent outpost on the surface, which will most likely take the form of the International Moon Village – an ESA-led project aimed at creating a spiritual successor to the ISS on the Moon.

The construction process will also help NASA test the various systems and technologies that will be used to send crews and freight to Mars. In addition, it will provide a preparation area for missions to Mars, through the addition of Deep Space Transport.

This spaceship – aka. Mars Transit Vehicle (MTV) – will include two components: an Orion capsule and a powered housing module. Basically, after launching a crew from the Earth aboard an Orion spacecraft, he will go to the rendezvous with the LOP-G and re-enter the capsule at the DST to get to Mars.

The DST would rely on electric solar powered engines to make the journey over several months. According to specifications published by NASA, the ship will be able to accommodate a crew of four and can remain in operation for 1,000 days without maintenance, for a total operational life of 15 years.

The DST will also be used for the transport and assembly of the final piece of mission architecture: the Mars and Lander base camps, both developed by Lockheed Martin. Which brings us to …

Phase III: Independent of the Earth

In this final phase of the "Journey", the astronauts will create another habitat in orbit around Mars. Known as the Mars Base Camp (MBC), this habitat will resemble the LOP-G, consisting of a series of integrated modules powered by solar panels.

The station will have all the necessary amenities for a crew of four and will include a laboratory module to conduct key scientific operations on the Martian surface.

These include the ongoing search for clues of past Martian life (and even present), research that has been conducted extensively in recent years by robotic missions such as the Opportunity rover and Curiosity.

The creation of the MBC will allow NASA and other space agencies to further this research. For example, one of the main goals of the March 2020 rover is to collect samples of Martian soil, which will then be left in a cache for possible recovery.

When the astronauts arrive on Mars, they will collect these samples and bring them back to Earth via Mars Base Camp. This will be the first Martian mission back samples in history and should say a lot about the past, the present and the history of the planet.

Like the LOP-G, future missions to the surface will be possible thanks to the Mars Lander. Again, the lander will host missions that could last up to two weeks and up to four astronauts. He will also be able to return to Mars Base Camp without surface refueling or leave assets behind.

Are we about to make the next big leap?

All this sounds exciting. But how are we on the point of gathering all the pieces of this mission? To put it plainly, not very much. While the Orion capsules that will be used for EM-1 and EM-2 are assembled, the SLS is still in development.

According to NASA's SLS Monthly Highlights, which provides regular updates on the development process, the Core Stage of the rocket that will launch the EM-1 in the space is getting closer.

According to the report released from December 2018 to January 2019, the production of liquid oxygen tank, inter-tank flight objects and SLS Core Stage front skirt skirts for the rocket has been completed. These were then sent to the NASA Michoud Assembly Facility in New Orleans for testing and assembly.

Combined with the research being conducted aboard the ISS, particularly with regard to the long-term effects of microgravity on astronaut physiology, NASA stands squarely in Phase I of mission development. In short, they are a little late.

Initially, NASA was hoping to conduct operations in the cis-lunar space in the mid-2020s and a crewed mission to Mars by the 2030s. However, since the release of Space Policy Directive 1, NASA has moved from "Journey to Mars" to renewed missions on the Moon (although missions to Mars have been included as a possible goal).

Based on their latest estimates, NASA now anticipates that work on the LOP-G will start with EM-3 in 2024 and end in the late 2020s. According to these estimates, crew missions on the lunar surface should take place before the end of the next decade.

Another problem since 2017 is the uncertain fiscal environment. Currently, no mission is funded beyond EM-3 and, as of 2018, NASA has not formally included Deep Space Transport in an annual US Federal Budget cycle. – although she continues to search for it as an idea. The same goes for the base camp and the Lander of Mars.

Due to changing priorities and concerns about NASA's future budget, many questions arise as to whether the "Travel to Mars" will still occur. Even though it has not been abandoned, it is simply impossible to know if NASA will be able to send astronauts to the red planet by 2030.

Essentially, the "Journey to Mars" is somewhat fixed and could be pushed a little further. For this to happen within the timescales originally specified, NASA would need a solid financial commitment that will cover the next decades.

But given the nature of American politics, we can not count on that. Administrations change every four to eight years, priorities change and budgets need to be voted on regularly. However, for the moment, no one intends to cancel NASA's next big jump. It only remains to be seen when it will be possible.

Similarities between the "Journey to Mars" and the Apollo program:

In many ways, the Apollo program and NASA's intention to send astronauts on Mars in the next two decades are very similar. In addition to being ambitious and requiring a very serious commitment in terms of time, resources and talent, both programs will require advanced equipment and technologies.

If and when a crewed Mars mission takes place (and assuming they arrive there first), NASA will have reaffirmed its position in space. By "getting there first" as they did with Apollo 11, NASA will have demonstrated that they are still the leader in space exploration and technology.

Beyond that, the two programs are quite different. On the one hand, the Apollo program was a "Moonshot", which meant that it was a direct mission. Everything had to be carried by the launcher and the spacecraft, which meant that the launcher had to be big and carry a huge amount of fuel. In addition, all the components involved were expendable goods and had to be scrapped by the end of the mission.

On the other hand, NASA's projects for crewed Mars missions involve an indirect approach. Pendant des décennies, il y a eu des partisans d'une mission "Mars Direct", dont le plus célèbre est le célèbre ingénieur en aérospatiale Robert Zubrin (qui a écrit Les arguments en faveur de Mars: le plan de règlement de la planète rouge et pourquoi nous devons).

Cependant, plutôt que de procéder à un "tir sur Mars" cette fois-ci, la NASA a choisi d'adopter l'approche indirecte. Comme indiqué ci-dessus, cela implique de s'appuyer sur plusieurs composants du vaisseau spatial, d'établir des habitats spatiaux et des points de ravitaillement en carburant entre l'espace cis-lunaire et l'orbite martienne, et d'utiliser des véhicules réutilisables (comme le DST et les atterrisseurs lunaires et martiens).

Cette approche, même si elle prendra plus de temps qu'une mission Mars Direct, permettra des missions de durée, de souplesse et de valeur scientifique plus importantes. Cela mènera également à la création d'une infrastructure pouvant être utilisée encore et encore pour effectuer des missions sur la surface lunaire et martienne. Et même si cela coûtera plus cher à court terme, il sera plus rentable et efficace à long terme.

En 1962, lorsque Kennedy prononça son célèbre discours, la NASA s'était engagée à envoyer des astronautes sur la Lune d'ici la fin de la décennie. En 2010, lorsque la NASA a dévoilé son plan d’envoi d’astronautes sur Mars, ils avaient l’intention de le faire au cours des deux prochaines décennies et de manière plus efficace.

Ne souhaitant plus simplement "y arriver le premier", l'objectif est désormais d'établir un plan durable pour l'exploration spatiale. De manière tout aussi importante, l'infrastructure créée permettrait également d'effectuer des missions dans d'autres espaces lointains tels que la ceinture d'astéroïdes, les lunes de Jupiter et éventuellement les lunes de Saturne.

Ces parties du système solaire sont non seulement riches en ressources (métaux, eau, méthane et ammoniac), mais les lunes d’Europa et de Ganymède sont connues pour avoir des océans d’eau salée sous leurs croûtes glacées qui pourraient soutenir la vie. Les stations spatiales situées entre la Terre et Mars pourraient faciliter les missions qui permettraient enfin d’enquêter de près sur ces lunes.

Conclusion:

Invariablement, l’atterrissage de la Lune et l’intention de la NASA d’envoyer des astronautes sur Mars sont connectés, et pas seulement de la manière que vous pensez. En substance, la proposition de la NASA de renvoyer les astronautes sur la Lune et sur Mars dans un avenir proche (et la façon dont ils prévoient de le faire) est un résultat direct du programme Apollo.

Oui, nous n'envisagerions pas d'envoyer des astronautes sur Mars maintenant si nous ne les avions jamais envoyés sur la Lune à la fin des années 60 ou au début des années 70. Mais plus précisément, il ne nous aurait pas fallu aussi longtemps pour envisager de retourner sur la Lune et de passer à l'étape suivante si Apollo s'était déroulé différemment.

Fondamentalement, le programme Apollo était un projet incroyablement ambitieux et coûteux. un "Moonshot". En termes d’histoire de l’exploration humaine, c’était le plan le plus audacieux jamais conçu. Son succès a non seulement cimenté la présence de l'humanité dans l'espace, mais a également été une source d'inspiration pour les générations futures.

Cependant, cela signifiait une dépense massive en ressources, non durable. Après Apollo 17, la NASA a dû faire face à un nouvel environnement budgétaire et à une nouvelle orientation. Désormais, les agences spatiales du monde doivent se concentrer sur les types de technologies qui permettraient à l’humanité de sortir une fois de plus dans l’espace et d’y rester.

Oui, cela fait plus de cinq ans et demi que l'homme n'a pas mis les pieds sur la Lune. Mais grâce aux développements survenus depuis, tels que les engins spatiaux réutilisables, la propulsion ionique, les stations spatiales et de multiples missions robotiques sur la Lune et sur Mars, la prochaine incursion de l'humanité dans l'espace (tout en étant progressive et progressive) sera durable.

Nous retournons sur la Lune puis sur Mars. Seulement cette fois, nous prévoyons de rester!

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