Why Is It Taking Us so Long to Get Back to the Moon?

For the next five decades, all missions that were mounted by NASA and its chief rival – Roscosmos, the Russian federal space agency – would be focused on operations in Low-Earth Orbit (LEO). But by the mid-2000s, NASA began taking the necessary steps that would eventually lead us back to the Moon.

These steps have culminated in recent years in the form of both NASA’s proposed “Journey to Mars” and its plans for renewed missions to the lunar surface. While there is still much to be done before either can take place, NASA estimates that it will be able to send astronauts to the Moon again no later than the end of the next decade.

Which begs the question: why is it taking us so long to go back to the Moon? If NASA is able to send crewed missions to the lunar surface by 2029 at the latest, it will have been sixty years since the Moon Landing took place (and fifty-seven years since the last Apollo mission sent astronauts to the Moon). So why the incredibly long intermission?

Well, to answer that, some very important questions need to be addressed first. For starters, what did it take to get to the Moon in the first place? What did we learn from the first “Moonshot”? And, just as important, what will be involved in making the next great leap in space exploration – i.e. the proposed “Journey to Mars”?

The Challenges of Making a “Moonshot”:

On Sept.12^th, 1962, US President John F. Kennedy made his famous “We choose to go to the Moon” address. This speech was meant to encourage support among the American population for the Apollo Program, which had commenced two years prior.

In addition to outlining the benefits that the program would entail, Kennedy stressed that one of the main reasons for conducting a lunar program was the challenge that it represented. As he put it:

“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."

The challenge, simply put, was monumental. By the early 60s, NASA had become proficient at sending astronauts into orbit. Project Mercury, which was NASA’s first effort to send astronauts into space, had wrapped up and Project Gemini was well underway. As part of Mercury, six American astronauts had been sent orbit, culminating in Gordon Cooper’s 22 orbits of Earth.

By 1966, ten two-astronaut crews were sent to Low Earth Orbit (LEO) as part of Gemini. However, to send astronauts to the Moon, NASA needed to invest in a whole new breed of rockets and spacecraft. The single stage Redstone and Atlas rockets and the two-stage Titan II rockets were well-suited to sending astronauts into orbit.

But to reach the Moon, NASA would require a heavy-lift launch vehicle and a spacecraft capable of both reaching the lunar surface and bringing the astronauts back to Earth. For this purpose, the Saturn rocket family was developed and for the crewed missions, nothing short of the Saturn V would do. 

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

Similarly, a spacecraft of three modules was required to take the astronauts to the Moon and then bring them back home. These included the Command Module (CM), the Service Module (SM), and the Apollo Lunar Module (ALM). The CM would hold the crew of four, the SM would provide propulsion for the entire spacecraft, and the ALM would allow two of the three astronauts to land on the Moon and then return to lunar orbit.

The ALM also came in two sections: the ascent stage and the descent stage. As the names would suggest, the descent stage was what would allow the two-person lander crew to descend to the lunar surface and was where the astronauts stored their equipment. The ascent stage is where the crew compartment was located, and which would allow the astronauts to take off again.

The plan was relatively straightforward. The Saturn V would launch from Earth, the first stage would boost the rocket to orbital velocity and then be discarded, burning up in Earth’s atmosphere. At this point, the second stage would ignite, bring the rocket and spacecraft to an altitude of 185 km (115 mi), and then be discarded in Earth orbit.

The third and final stage would then ignite and push the spacecraft into translunar trajectory (speed of 24,500 mph) before finally being discarded. At this point, the combined Command and Service Modules (CSM) would take the three-astronaut crew and the ALM to the Moon.

Once they reached lunar orbit, the ALM would separate from the CSM and take two astronauts down to the surface where they would conduct science operations. Once the astronauts were finished, they would board the ALM and the ascent stage would blast off (leaving the descent stage behind) and rendezvous with the CSM in orbit.

The CSM would then break orbit and insert the spacecraft into a transearth injection, taking them all the way back home. Once they reached Earth, the CM and SM would separate, and the CM would land in the ocean and the crew would be retrieved. Mission accomplished.

All of this hardware and an intense amount of training and technical expertise was necessary in order to send astronauts to the Moon. The investment would result in the creation of thousands of jobs, invaluable experience for the astronauts, engineers and support crews, numerous commercial applications and scientific advancements, and a cultural impact that is still being felt today.

So why is it taking us so long to go back? The challenges were certainly great, but are they somehow beyond the current generation, unlike our forebears? The simple answer is no, but with some caveats. To answer the question effectively, we have to consider one salient aspect of the Apollo Program that is often overlooked.

How Efficient was the Apollo Program?

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

However, it is possible to put a price tag on the Apollo Program itself, and it has been done. According to the 1974 NASA Authorization Hearings, the Apollo missions cost US taxpayers $25.4 billion USD, which adjusted for inflation works out to about $144 billion dollars today.

But of course, you have to factor in the costs of Project Mercury and Project Gemini, since they were key stepping stones to Apollo. When you do that, you come to a grand total of about $159 billion. In other words, it took $22 billion to establish a working space program that could put astronauts into orbit and prepare them to go to the Moon.

Meanwhile, actually sending them to the Moon cost over six and a half times more than the previous two projects combined. Where did all this money go?

Well, it went into the development of the rockets and spacecraft that were powerful enough to take astronauts (and all of their equipment and supplies) to the Moon in a single shot. This, and the amount of fuel required to do it meant that the launch vehicles had to be very large and powerful, and therefore very expensive.

Also, both the launch vehicles and the spacecraft that allowed astronauts to get the Moon, land on it, conduct surface operations, and then return home, were entirely expendable. Once the three stages of the Saturn V rockets were spent, they either fell into the ocean or became space junk in orbit.

The same is true of the Command, Service and Lunar Modules, which ended up on the lunar surface, in space, or the ocean by the end of each mission. None of the mission architecture was designed to be reused, which meant that everything was designed to be used up and then thrown away.

And when the Apollo Program was over, there was nothing lasting or reusable established between Earth and the Moon. No space stations, no refueling depots, and no lunar base - nothing that would allow for renewed missions to the Moon in the near future.

The Saturn V’s were retired, and all the infrastructure established to build and maintain them (as well as all other aspects of the Apollo Program) was decommissioned.

In short, the Apollo Program was not efficient, not by a long shot. But of course, it was not meant to be. For NASA, the entire purpose of the program was to get to the Moon as quickly as possible, not to mention beating the Russians to it. Speed was of the essence, not a slow and gradual build-up that would eventually lead to the lunar surface.

If NASA had been looking to create a long-term, sustainable and efficient way for reaching the Moon, they would have taken a gradual approach that would have probably taken decades. This would likely have involved using existing single and two-stage rockets to build a space station in Low-Earth Orbit.

This station would then serve as a departure and arrival point for a spacecraft that would transport astronauts to and from the Moon. In lunar orbit, a second space station would need to be built, where the spacecraft would rendezvous and transfer the astronauts to a lunar module. This module would then take them to the surface and back up to orbit again.

If this is starting to sound familiar, it's probably because it closely resembles what Arthur C. Clarke envisioned in Stanley Kubrick's 2001: A Space Odyssey. Released in 1968, roughly a year before the Moon Landing took place, this vision of the future was based on Clarke's extensive knowledge of physics and space exploration. It, therefore, made sense from a scientific standpoint.

However, given the historical context in which the Apollo Program took place, it is unreasonable to expect that they would have chosen to take the slow and steady approach. Even if it meant that there wouldn't have been such a large intermission between the first Moon landings and the next, the first Moon Landing would probably not have happened until the 1980s.

In any case, once the Apollo Program was complete, both NASA and their Russian counterparts were forced to scale back and start thinking about long-term and cost-effective goals. The US had effectively won the “Space Race”, now it was time to focus on taking the next steps.

In order to do that, the cost of launching payloads and crews into space needed to be drastically reduced and technologies that would allow for a long-term human presence in space needed to be developed. These included the development of reusable spacecraft and space stations.

For NASA, these efforts bore fruit with the creation of the Space Shuttle, which consisted of two solid rocket boosters, an external fuel tank, and the Orbital Vehicle (OV). For the Russian’s, it achieved fruition in the form of the Buran Spacecraft, which was closely modeled on the Space Shuttle.

In terms of space stations, Roscosmos took an early lead with the launch of the six Salyut space stations (1971 to 1986) and Mir (1986-1996). Meanwhile, NASA made significant strides with the deployment of Skylab (1973-1979). By the 1990s, both organizations came together with other space agencies to create the International Space Station (ISS).

These and other developments would play an important role in helping NASA to get to the point where bold, new initiatives could be considered. These include the current plans to send astronauts back to the Moon, and on to Mars as well.

When will we able to make the next great leap?

Plans for the “Journey to Mars” began in earnest with the passing of the NASA Authorization Act of 2010 and the U.S. National Space Policy that was issued that same year. This act reaffirmed NASA’s commitment to the International Space Station, to partnerships with commercial entities, and to the development of essential space exploration technologies. 

But most importantly, this Act also directed NASA to take the necessary steps to create the mission architecture that would allow for the first crewed missions to Mars in the next two decades. These steps were broken down into three phases:

Phase I: Earth Reliant

This phase includes the restoration of domestic launch capability to the United States. With the retiring of the Space Shuttle in 2011, NASA was dependent on Roscosmos to send astronauts to the ISS using their time-tested Soyuz rockets. For smaller payloads, NASA relied on commercial launch providers like United Launch Alliance (ULA), Orbital ATK, SpaceX and others.

But to send astronauts to locations in deep space, NASA needed a new class of heavy launch vehicle that was capable of rivaling the Saturn V. This vehicle is the Space Launch System (SLS), a massive rocket designed (and currently being manufactured) by Boeing, ULA, Northrop Grumman, and Aerojet Rocketdyne.

The design combines elements of the Space Shuttle (the solid rocket boosters) with the core stage of the Constellation Program’s rocket designs (a modified version of the Space Shuttle’s external tank). With a total thrust of 32,000 kilonewtons (7,200,000 pound thrust), the SLS will be the most powerful rocket in history.

NASA also needed a new crew exploration vehicle that would be able to transport crews of up to six astronauts and plenty of equipment. This was achieved with the Orion Multi-Purpose Crew Vehicle (MPCV), a joint project between NASA and the European Space Agency (ESA) designed by Lockheed Martin and Airbus.

At present, work has been completed on two Orion capsules, which will be sent into space in the coming years. In the meantime, NASA is still researching the effect that long-duration space flights will have on astronaut health and physiology (which includes the Twin Study).

At the same time, they are investigating various technologies that will come into play down the road, such as additive manufacturing (3D printing), advanced communication systems, environmental control and life support systems for Mars, and Solar Electric Propulsion (SEP) - a form of ion propulsion.

Which brings us to...

Phase II: Proving Ground

Once the SLS and the Orion spacecraft are up and ready to go, NASA will begin mounting a series of missions to see how they fare in space. Initially, the plan was to conduct a mission to a Near-Earth Asteroid (NEA) during the 2020s to validate the spacecraft to develop the necessary astronaut expertise.

Known as the Asteroid Robotic Redirect Mission (ARRM), this would consist of sending a robotic spacecraft to capture and tow an NEA into lunar orbit. This was to be followed by a crewed Orion spacecraft being sent to explore the asteroid and returning samples to Earth.

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

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

By 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-Gateway (LOP-G) – the next big piece of the overall mission architecture. Formerly known as the Deepspace Gateway, the LOP-G is a NASA-led international project to create a solar-powered habitation module in orbit of the Moon.

This station will orbit the Moon every six days and allow for science operations to be conducted on the lunar surface. These will include sample-return missions, similar to what the Apollo astronauts conducted, as well as tests involving vehicles and equipment ultimately destined for Mars.

Trips to the surface will be facilitated thanks to the addition of a reusable lunar lander. These missions could last for up to two weeks before having to return to the Gateway, without the need for maintenance or having to refuel on the surface. The station is scheduled to be complete by the mid-2020s and is intrinsic to NASA's plan to conduct renewed 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 (i.e. lunar tourism). It will also play a vital role in the creation of a permanent outpost on the surface, which will most likely take the form of the International Moon Village - an ESA-led project to create 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 cargo to Mars. In addition, it will provide a staging area for missions to Mars, thanks to the addition of the Deep Space Transport.

This spacecraft - aka. the Mars Transit Vehicle (MTV) - will consist of two elements: an Orion capsule and a propelled habitation module. Basically, after a crew is launched from Earth aboard an Orion spacecraft, they will rendezvous with the LOP-G and reintegrate the capsule to the DST to travel to Mars.

The DST would rely on Solar Electric Propulsion engines to make the journey over the course of several months. Based on specifications released by NASA, the ship will accommodate a crew of four and be able to remain in operation for 1000 days without maintenance, with a total operational life of 15 years.

The DST will also be used for the transportation and assembly of the final piece of the mission architecture: the Mars Base Camp and Lander, both of which are being developed by Lockheed Martin. Which brings us to...

Phase III: Earth Independent

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

The station will have all the necessary amenities for a four-person crew and will include a laboratory module for conducting key science operations on the Martian surface.

These include the ongoing search for indications of past (and even present) Martian life, a search which has been conducted extensively in recent years by robotic missions like the Opportunity and Curiosity rover.

The creation of the MBC will allow NASA and other space agencies to expand on these searches. For instance, one of the main goals of the Mars 2020 rover is to gather samples of Martian soil, which will then be left in a cache for eventual retrieval.

When astronauts arrive at Mars, they will collect these samples and return them to Earth via the Mars Base Camp. This will be the first Martian sample-return mission in history and is expected to reveal much about the planet's past, present, and its evolutionary history.

Like the LOP-G, the eventual missions to the surface will be possible thanks to the Mars Lander. Here too, the lander will be able to accommodate missions to that would last for up to two weeks by up to four astronauts. It will also be able to return to the Mars Base Camp without surface refueling or leaving assets behind.

How close are we to making the next great leap?

It all sounds exciting. But how close are we to put all the pieces of this mission together? To put it plainly, not very. 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 EM-1 into space is coming together.

According to the report issued for December 2018 to January 2019, production was completed on the SLS Core Stage liquid oxygen tank, intertank and forward skirt flight articles for the rocket. These were then shipped to the NASA Michoud Assembly Facility in New Orleans to be tested and assembled.

Combined with the research that has been conducted aboard the ISS, particularly in terms of the long-term effects of microgravity on astronaut physiology, this places NASA squarely in Phase I of mission development. In short, they are a little behind.

Originally, NASA hoped to conduct operations in cis-lunar space during the mid-2020s and a crewed mission to Mars by the 2030s. However, since Space Policy Directive-1 was issued, NASA's focus has shifted from the "Journey to Mars" to conducting renewed missions to the Moon (though missions to Mars were included as an eventual goal).

Based on their latest estimates, NASA now anticipates that work on the LOP-G will begin with EM-3 in 2024 and will finish by the late 2020s. By these same estimates, crewed missions to the lunar surface are expected to take place before the end of the next decade. 

Another issue since 2017 has been the uncertain budget environment. Currently, no missions are being financed beyond EM-3 and as of 2018, NASA has not officially included the Deep Space Transport in an annual U.S. federal government budget cycle - though they continue to research it as an idea. The same is true of the Mars Base Camp and Lander.

Thanks to shifting priorities and concerns about NASA's future budget, there are a lot of questions about whether the "Journey to Mars" is still going to happen. While it has not been scrapped, it is simply not clear whether NASA will be able to send astronauts to the Red Planet by the 2030s anymore.

Essentially, the "Journey to Mars" is in a bit of a holding pattern, and could end up being pushed back a little farther. To make it happen in the timeframe that was originally specified, NASA would need a robust commitment in funding that will cover the next few decades.

But given the nature of US politics, this is not something that can be counted on. Administrations change every four to eight years, priorities shift, and budgets need to be voted on regularly. However, at this juncture, no one is intent on canceling NASA's next great leap. It just remains to be seen when it will be possible.

Similarities between the “Journey to Mars” and the Apollo Program:

In a lot of ways, the Apollo Program and NASA's intent to send astronauts to Mars within two decades are very similar. In addition to being similarly ambitious and requiring a very serious commitment in terms of time, resources and talent, both programs will require cutting-edge hardware and technology.

If and when a crewed mission to Mars takes place (and assuming they get 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 when it comes to space exploration and technology.

Beyond that, the two programs are rather dissimilar. For one, the Apollo Program was a "Moonshot", meaning that it was a direct mission. Everything had to be carried by the launch vehicle and spacecraft, which meant that the launch vehicle had to be big and carry a tremendous amount of fuel. Moreover, all of the components involved were expendable and meant to be discarded by the end of the mission.

In contrast, NASA's plans for crewed missions to Mars involve taking an indirect approach. For decades, there have been proponents of conducting a "Mars Direct" mission, not the least of which is famed aerospace engineer Robert Zubrin (who wrote The Case for Mars:  The Plan to Settle the Red Planet and Why We Must).

However, rather than conduct a "Mars shot" this time around, NASA has chosen to take the indirect approach. As noted above, this includes relying on several spaceship components, establishing space habitats and refueling points between cis-lunar space and Martian orbit, and using reusable vehicles (like the DST and the lunar and Mars landers).

This approach, while it will take longer than a Mars Direct mission, will allow for missions of greater duration, flexibility, and scientific value. It will also lead to the creation of infrastructure that can be used again and again to conduct missions to the lunar and Martian surface. And while it will be more expensive in the short run, it will be more cost-effective and efficient in the long run.

In 1962, when Kennedy made his famous speech, NASA was committed to sending astronauts to the Moon by the end of the decade. In 2010, when NASA unveiled its plan to send astronauts to Mars, they were intent on doing so within the next two decades, and in a way that is more efficient.

No longer intent on simply "getting there first", the goal has shifted to establishing a sustainable long-term plan for space exploration. Just as importantly, the infrastructure created would also allow for missions to other locations in deep space - such as the Asteroid Belt, the moons of Jupiter, and possibly the moons of Saturn.

Not only are these parts of the Solar System rich in resources (metals, water, methane, and ammonia), the moons of Europa and Ganymede are known to have salt-water oceans beneath their icy crusts that could support life. Space stations between Earth and Mars could facilitate missions that would finally be able to investigate these moons up-close.

Conclusion:

Invariably, the Moon Landing and NASA’s intent to send astronauts to Mars are connected, and not just in the ways you may think. In essence, NASA’s proposal to send astronauts back to the Moon and on to Mars in the near future (and the way they plan to do it) is a direct result of the Apollo Program.

Yes, we wouldn't be contemplating sending astronauts to Mars now if we had never sent them to the Moon in the late 60s/early 70s. But more to the point, it wouldn't have taken us this long to contemplate returning to the Moon and taking the next step if Apollo had happened differently.

Basically, the Apollo Program was an incredibly ambitious and expensive project, aka. a "Moonshot". In terms of the history of human exploration, it was the boldest plan ever mounted. Its success not only cemented humanity's presence in space but has served as a source of inspiration for generations.

However, accomplishing it meant a massive expenditure in resources, one which was not sustainable. After Apollo 17, NASA was forced to contend with a new budget environment and a shifting focus. Henceforth, the space agencies of the world needed to focus on the kinds of technologies that would allow humanity to step out into space once again, and also stay there.

Yes, it has been over five and a half decades since human beings last set foot on the Moon. But thanks to the developments that have taken place since then - such as reusable spacecraft, ion propulsion, space stations, and multiple robotic missions to the Moon and Mars - humanity's next foray into space (while gradual and incremental) will be a lasting one.

We're going back to the Moon and then we're going to Mars. Only this time, we plan on staying!

Further Reading:

• NASA "Journey to Mars"
• NASA - Explore Moon to Mars
• NASA - Apollo Missions
• NASA - What Was the Apollo Program?