Opinion: Awakening the Sleeping Satellite—The Value of Human Lunar Exploration

A photo of the Moon from Earth orbit, taken by the crew of the International Space Station. Will our natural satelitte harbor humanity's next outpost in space following the retirement of the ISS? Image Credit: NASA
A photo of the Moon from Earth orbit, taken by the crew of the International Space Station. Will our natural satellite harbor humanity’s next outpost in space following the retirement of the ISS? Image Credit: NASA

I blame you for the moonlit nights
when I wonder why
are the seas still dry?
don’t blame this sleeping satellite

— Tasmin Archer, “Sleeping Satellite” (1992)


Perfectly capturing the spirit and vision of the Apollo generation, British pop singer/songwriter Tasmin Archer lamented in her seminal song, “Sleeping Satellite,” humanity’s abandonment of the dream of a sustained human presence and establishment on the Moon, following the Apollo lunar landings of the 1960s and ’70s. The song’s somber reflection is also shared by most within the space advocacy community today, more than 40 years after the last Apollo mission sent humans to the Moon in 1972. Yet, following a large hiatus of inactivity, the last decade has seen a resurgence of the interest for a permanent and more sustainable return to the Moon.

From 2003 onward, the U.S. and other nations have resumed a steady series of robotic exploration of our nearest celestial neighbor, with a string of highly successful lunar orbiting missions. The European Space Agency’s SMART-1 probe, launched in 2003, was Europe’s first robotic mission to the Moon and the first to travel there using an ion xenon electric propulsion engine. It was followed by Japan’s SELENE in 2007 and China’s Chang’e 1 and Chang’e 2 missions in 2007 and 2010 respectively. India became the latest addition to the lunar exploration club of nations with the launch of its Chandrayaan-1 orbiter in 2008. The U.S. also led its own series of missions to the Moon with the launch of the Lunar Reconnaissance Orbiter/LCROSS probes in 2009, followed by GRAIL in 2011, and most recently with LADEE in 2013.

All of these missions have provided us with important and exciting new insights, creating a small paradigm shift in the way we view the Moon, while confirming the discovery of substantial amounts of frozen water at the bottom of permanently shadowed craters on the lunar south pole, which was made by NASA’s Lunar Prospector orbiter in 1998. Yet the most exciting lunar mission for the last 40 years is without doubt China’s Chang’e 3 lander, launched in December 2013. Whereas all the aforementioned spacecraft were lunar orbiters studying the Moon from above, the success of the Chang’e 3 mission entered China into the hall of fame that consists of the very few nations that have successfully soft-landed a spacecraft on the Moon—a feat previously conducted only by the U.S. and the former Soviet Union.

An artist's concept of a human settlement on the Moon. Image Credit: NASA/Pat Rawlings
An artist’s concept of a human settlement on the Moon. Image Credit: NASA/Pat Rawlings

Despite this plethora of activity by robotic spacecraft on and around the Moon, the official U.S. attitude in recent years regarding the establishment of a more permanent human presence there has been that of indifference. This view is clearly reflected on the “Global Exploration Roadmap” as well, crafted by the International Space Exploration Coordination Group, a coordination forum consisted of 14 space agencies worldwide that is dedicated to creating a unified worldwide space exploration vision for the following decades. The Roadmap acknowledges that “extending and sustaining human presence beyond low-Earth orbit enables humankind to live and work in space, to harness solar system resources for use in space and on Earth, and eventually to settle on other planets,” although the Moon has a minimal role to play toward achieving that goal. In the Roadmap’s layout, NASA’s ultimate goal is Mars, with the Moon being something like a “touch-and-go” destination on the way to the Red Planet. Although the space agency announced that a new public workshop will take place in April of this year to update the current version of the Roadmap, these updates will probably won’t have any significant change to the already defined goals.

Even though NASA has officially shown a general lack of interest toward the prospect of a human settlement of the Moon, its prospect still holds great appeal for many in and out of the space agency, from scientists to government officials to entrepreneurs. For the proponents of lunar exploration, the Moon is considered key for the construction of a permanent interplanetary space transportation system and the creation of a space-faring civilization.

The benefits stemming from a return to the Moon and the establishment of human outposts there are indeed numerous, positively influencing many different and diverse sectors from scientific research to technology development to economic growth. Such a human presence on our natural satellite holds the promise of advancing all of these areas independently and simultaneously. Yet all these benefits could be grouped into three main categories: science, human space exploration, and economic growth.

The Moon has been the most explored object in the Solar System. Dozens of robotic probes have orbited it, studied it, or landed on it. More importantly, 12 human beings have walked on its surface bringing back a total of 838.2 pounds (380.2 kg) of lunar rock and soil, elevating the meaning of “human exploration” to new heights. All this bulk of knowledge is the basis of our understanding for the evolution of the Earth-Moon system and of the age estimates for the rest of the terrestrial planets in the Solar System. Despite these insights, the Moon is in essence an unexplored land. “The vast majority of lunar terrains have never been directly sampled and their ages are based on the observed density of impact craters, calibrated against the ages of Apollo and Luna samples,” writes a team of scientists, led by Dr. Ian Crawford, Professor of Planetary Science and Astrobiology at London’s Birkbeck College, in a paper published in the journal Planetary and Space Science.

A scene from the British science fiction TV series 'Space:1999', showing an Eagle Transporter on one of the launchpads of Moonbase Alpha. Moonbases have been a staple of science fiction for many decades. Will scenes like this, become a reality? Image Credit: Network Video/Granada Ventures
A scene from the British science fiction TV series “Space:1999,” showing an Eagle Transporter on a launchpad on Moonbase Alpha. Moonbases have been a staple of science fiction for many decades. Will scenes like this become a reality? Image Credit: Network Video/Granada Ventures

Besides the need for studying the Moon’s geology and interior, the most important scientific rationales for returning humans to the Moon, according to Dr. Crawford’s team, might be the hands-on examination of the deposits of frozen water found on the Moon, and the study of human physiology during extended stays in low-gravity environments: “The processes involved in the creation, retention, migration, and destruction of OH and H2O across the surface of the Moon, are likely to be common on other air-less bodies, and quantifying them on the Moon will give us better insight into the volatile history and potential availability of water elsewhere in the inner solar system. The presence of water ice at the lunar poles, and even hydrated materials at high-latitude but non-shadowed localities, could potentially provide a very valuable resource in the context of future human exploration of the Moon.”

In-situ resource utilisation (or ISRU) of water and other resources on the Moon opens up the way to new and exciting capabilities for sustaining a human presence there. It has long been argued that ISRU is what’s needed to make human interplanetary spaceflight economically viable. The reason for this is because every launch vehicle used to launch humans and equipment into space has to carry the weight of its own propellant as well to reach orbit, ultimately limiting the total mass of the rocket’s main payload. By the time a spacecraft reaches low-Earth orbit, the bulk of the launcher’s fuels have been used. Any human crew heading for any deep space destinations has to either refuel on the way or create its own fuel from the resources it finds at its destination. The presence of water on the lunar poles, for example, means that future astronauts can tap into that and break it down to hydrogen and oxygen for rocket fuel. Oxygen could also be used as breathing air for human crews. The opposite method of combining these elements to create water could also help to sustain a human settlement on the Moon, providing both fresh water and radiation shielding. “Of course, no one knows if using space resources is even possible,” writes Dr. Paul Spudis, a lunar geologist and long-time advocate of human space exploration. That’s exactly why it’s such an interesting mission – we don’t know the answer ahead of time. Such a challenge has never been attempted by any nation or entity, but it is a skill that we must master if we are ever to become a true spacefaring (and space-inhabiting) species.”

Indeed, the exploitation of space resources on other celestial bodies still remains a theoretical possibility. Many concepts for human missions to Mars also rely, at least in some part, on in-situ resource utilisation. Trying out this technique on the Moon, compared to a “Mars first” scenario, would provide some significant advantages by helping to significantly reduce the risks inherent in such an endeavor, thus helping to guarantee a much bigger chance of mission success on more distant deep-space missions. The Moon’s relative close distance to the Earth means that human crews could exercise and perfect all the necessary procedures and techniques for what is needed to live on another world for prolonged periods of time. The lessons learned on the lunar surface could then be applied to other destinations, like Mars. “Lunar ISRU can harvest not only water (and thus, oxygen) but also methane from the Moon’s polar deposits,” writes Dr Spudis on his Lunar Resources blog. “Methane is the propellant [Robert] Zubrin’s Mars Direct architecture uses for Earth return… This means that we can test the methane ISRU systems not only in principle – we can test the actual Mars equipment in practice three days away on the Moon and in cislunar space. In effect, these lunar properties mean that a complete, end-to-end systems test of all the pieces of a Mars Direct-style architecture could be performed in cislunar space.”

Medicine and life sciences would also be greatly benefited by a sustained human presence on the lunar surface. “The Moon is a testing ground for technological principles and approaches for dealing with the major environmental parameters that affect life in outer space,” writes Dr. Ian Crawford’s team in its study. “For example, the Moon can be used to investigate whether the effects of gravity are linear or whether there are critical thresholds to the biological effects of the radiation environment beyond the Earth’s magnetosphere, and the toxicity of lunar dust.” In much the same way that the International Space Station is used today to study the effects of zero-gravity on human physiology and psychology, the Moon could similarly be used to study how a low-gravity environment can affect human crews during long stays on the lunar surface, prior to attempting more distant missions to deep-space destinations such as Mars.

The Earth rises above Shackleton Crater (right from center) in this high-definition image from the Japanese SELENE spacecraft, as it orbited the Moon in 2007. Measurements from various spacecraft have shown that the interior of Shackleton Crater is rich in trapped volatiles like water, making it a perfect source of lunar resources for the sustenance of a moon base. Image Credit: JAXA
The Earth rises above Shackleton Crater (right from center) in this high-definition image from the Japanese SELENE spacecraft, as it orbited the Moon in 2007. Measurements from various spacecraft have shown that the interior of Shackleton Crater is rich in trapped volatiles like water, making it a perfect source of lunar resources for the sustenance of a Moon base. Image Credit: JAXA

Yet for many the biggest reason for a return to the Moon is to help create of a whole new economy, by incorporating cislunar space to our economic sphere of influence. Countless plans by the private space sector have been proposed for the mining and exploitation of solar energy and lunar resources like minerals, water, and Helium 3. “The bulk of the stuff we need to develop an industrial complex on the moon is all over the place,” says Dr. Alan Binder, Director of the Lunar Research Institute in Tucson, Ariz. “We have a tremendous resource sitting out there.” One such private enterprise, the Texas-based Shackleton Energy Company founded in 2007, aims to be the first to exploit the water ice on the Moon’s south pole and transfer it to low-Earth orbit. Colorado-based Golden Spike Company on the other hand, aims to create the first commercial Earth-Moon space transportation network by 2020 enabling human trips to the lunar surface, for both governments and private organisations worldwide. “We can give countries an expedition to the surface of the Moon for two people,” says Dr. Alan Stern, the company’s co-founder. “Country after country, everyone will want to join the lunar club.”

Showing a desire for a wider partnership with the private sector following the successful conclusion of the ISS Commercial Orbital Transportation Services program, NASA announced a new initiative on Jan. 16 called Lunar Cargo Transportation and Landing by Soft Touchdown (or Lunar CATALYST for short). As stated in the initiative’s announcement, “NASA is seeking proposals to partner in the development of commercial robotic lunar lander capabilities. Such capabilities could support commercial activities on the moon while enabling new science and exploration missions of interest to the larger scientific and academic communities.” The space agency hopes that the same spirit of public-private cooperation that has led to a successful COTS program for low-Earth orbit transportation services could also be applied to cislunar space and the surface of the Moon as well.

The Chinese lunar lander Chang'e 3 photographed on the lunar surface, by the accompanying Yutu rover that was carried onboard. Image Credit: CSA/cnr.cn
The Chinese lunar lander Chang’e 3 photographed on the lunar surface, by the accompanying Yutu rover that was carried onboard. Image Credit: CSA/cnr.cn

All these different and diverse benefits coming from a human return to the Moon were summarised by the NASA-led Lunar Exploration Advisory Group which recently released a flyer titled “Destination Moon,” with the purpose of lobbying the members of Congress that oversee NASA’s budget to make the Moon a clear goal again for the U.S. space agency. The Group’s sentiments are also shared by Rep. Frank Wolf (R-VA), a long-time supporter of NASA. In a letter sent to President Obama in late 2013, Wolf expressed his concerns for the current state of indifference towards our nearest celestial neighbor: “As China prepares to send a series of increasingly advanced rovers to the Moon in preparation for what most observers believe will ultimately be human missions, many are asking why the U.S. is not using this opportunity to lead our international partners in an American-led return to the Moon.”

Perhaps the biggest obstacle toward charting a course back to the Moon is the “been there, done that” mentality that is very popular among many within the space community, in and out of NASA. This view, also shared by the space agency’s current leadership, has caused much controversy among space advocates ever since it was expressed by President Obama during a speech at the Kennedy Space Center in 2010. Elon Musk, CEO of the highly successful Space Exploration Technologies Corporation or SpaceX, echoed NASA’s current stance on the matter during a recent interview: “The next step is to maybe send people beyond low Earth orbit to a loop around the Moon, possibly land on the Moon — although I’m not super interested in the Moon personally, because obviously we’ve done that and we know we can — but maybe just to prove the capability.”

Maybe the best answer to this viewpoint has been given by the late Neil Armstrong, during a testimony on the House Committee on Science and Technology in 2010. “Some question why America should return to the Moon,” Armstrong said during his testimony. “After all,” they say, “we have already been there.” I find that mystifying. It’s as if 16th Century monarchs proclaimed that “We need not go to the New World, we have already been there.” Or if President Thomas Jefferson announced in 1808 that Americans “need not go west of the Mississippi, because Lewis and Clark have already been there.”

The simple truth of the matter is that neither SpaceX, nor the NASA of today, have sent any humans to the Moon. The epic accomplishments of Apollo belong to a previous generation of nearly 50 years ago. Once the Apollo program was cancelled and its workforce was dismantled and absorbed by other projects, the U.S. lost all of the capability it had gained to land humans on the lunar surface. Once a certain spaceflight capability is lost, many years or decades may pass until it is regained, if at all. In essence, NASA and the space sector in general must rebuild the necessary infrastructure, assemble the workforce, and re-learn what the engineers of Apollo knew from scratch, in order to return to the Moon. Commenting along these lines on the space agency’s currently built Space Launch System, Anthony Young writes on the Space Review that “for the first time in nearly half a century, the United States will, in a matter of a few years, have the launch capability to send crewed spacecraft to the Moon. The launch vehicle that could make that possible is the Space Launch System.”

Only time will tell if the hour has come for the U.S. to continue what it had started on that magnificent July night back in 1969.

Video Credit: InSpace Inc /Rick Tumlinson


The opinions presented in this article belong solely to the author and do not necessarily represent those of AmericaSpace.


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  1. A superb article, Leonidas. In my mind, it makes perfect sense to re-start our Beyond Earth Orbit (BEO) exploration by returning on a permanent basis to our closest celestial neighbour. I’ve never quite understood the rationale behind the “asteroid-first” proposal, which I find perplexing and questionable in its scientific purpose. It seems to me to be the work of politicians, skirting around the space programme as a way of avoiding funding grander aims. If we are ever going to travel to Mars and establish a permanent human outpost, where better to test technologies and gain experience than on a well-studied celestial body, just 3 days away from home? Great article.

  2. If God wanted man to become a space-faring species,
    He would have given man a Moon.
    -Krafft Ehricke

    The Moon is the first milestone on the road to the stars.
    -Arthur C. Clarke

    • Excellent quotes Jim, stating the obvious. Let’s hope policy makers recognise it as well.

  3. Well, you can dock with an asteroid as opposed to landing on it. I think SLS should be pushed for heavy outer planet probes to get JPL to get off the Delta II sounding rocket addiction that Dan Golden handed out like lollypops to keep planetary scientists from screaming.

    SLS will allow Europa and ice giants to be explored. Let Musk have LEO.

    • Only five more Delta II’s remain in ULA’s inventory before it is decommissioned, and NASA has already purchased four of them for future flights, with the last in 2016.

      Indeed, it’s high time for a heavy-lift vehicle like the SLS.

  4. The most important point in Leonidas’s article is using the Moon to develop and practice the techniques of living and working on another celestial body – a mere quarter million miles away. Imagine not only the technical breakthroughs but the exciting discoveries that await us on our neighbor! It is a logical next step before we attempt ambitious missions to Mars and beyond. Neil Armstrong was right – it makes no sense to stop exploration because of the short-sighted “been there, done that” mentality. I have always believed that it is “chump change” to continue human exploration of space – especially with the billions and billions of wasted taxpayer dollars funding dubious social “programs.” If we do not pursue this phase of manned space exploration, who will? The Chinese?

    • There’s a real possibility Tom, that the answer to your last question is ‘yes’. In the long run, it’s important that this step out into the Cosmos is made anyway, no matter by whom. But still, it would be a tragedy if the US doesn’t honor its spaceflight past, by ensuring an equally bright spaceflight future.

  5. If challenge comparable with that of JFK in 1961 should be articulated by any of the future presidents, it should be not less than quest for relocation of all space related R&D to the surface of Moon. However ridiculously looking if face of our current crises and lack of political will, that only endeavor would be able to create an environment attractive to broad range of scientists and technicians, mainly because of a vast pool of creativity and skills concentrated there. Think of Los Alamos Range, the Oppenheimer-proposed concentration of gray matter, but now devoted to space exploration and colonization.

    It involves not only laboratories for extensive basic and applied research in in-situ resource utilization, or nuclear and ion propulsion system development centers with playground next door (or two) away, it encompasses an university (Space Academy) as well, expressing the freedom of creative thinking together with obligation to preservation of knowledge. Biomedical sciences are for prolonged – rather sustained – human presence in space of key value; we still have to learn how to build a space station that does not turn into a biohazard in mere 10 years. I can imagine that the university clinic becomes one day a major supplier of peer-reviewed articles in medical journals. And think about telescopes that would not become obsolete at the moment of launch; rather, being constantly kept at edge of solid-state and optical technology, by hundreds of engineers and astronomers providing basic research in novel concepts of large-scale optical interferometry… Magnetic catapults, space-borne fabrication processes, regolith-sourced 3D printers… the list is endless. And how about free space quantum communication & entanglement experiments in a place where space vacuum and working desks are not mutually exclusive?

    And when one asks how much will these tens-of-thousands of moon-based scientists, engineers, students and support personnel costs, simply, it will cost precisely the amount of the people involved in. What ratio of citizens should be involved in, when a society is going to be space-faring, or space-colonizing? Besides, buying a new home is always a considerable investment.

  6. Leonidas
    You have given us all great detail again and with Golden Spike saying that humans will be back on the Moon by 2020 I am excited. Once SpaceX reusabilty of launch craft is established I think the moon will be the first target of commerce in a hugh way…Cannot hardly wait…

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