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© 2006 by Donald F. Robertson.


This article may be distributed at will, but only if it is not changed in any way, and only if the author's name, the copyright notice, the name of the journal it first appeared in, and this notice remain attached. In addition, this article may not be sold for money, or published for sale in any way, without the author's prior written permission.

This article originally appeared in Meme Therapy


A Scientific Justification for Human Lunar Exploration


Donald F. Robertson

A Web site asked me to answer the following question.  I did, and my answer amounts to a scientific justification for human lunar exploration.

If you had the power to resurrect a space program that was canceled or never got off the ground which one would you choose?

My answer now is probably significantly different than it would have been in even a few years ago, but my answer today is Apollo. After spending vast sums creating the transportation infrastructure required to send scientists to Earth’s moon, we let it go long before it could realize its potential. As Lyndon Johnson put it before it actually happened, we would “piss it all away.”

If Apollo had continued, we would have learned far more science on Earth’s moon than any set of automated missions could have achieved. Maybe we would not have had quite as extensive a scientific survey of the Solar System as we have today, but we would have gained truly detailed knowledge of the kind of regolith-dominated surface that most extraterrestrial bodies have. (A regolith is a “soil” without biology – essentially, mechanically processed rocks and fines.) We would also have gained crucial experience in survival on the types of world that dominates the inner Solar System. Moreover, the Saturn-V transportation infrastructure would have been steadily improved, rather than attempting the Shuttle project’s premature and generally unsuccessful leap to reusable launch vehicles. For the money we’ve spent in Earth orbit failing to reduce the cost of orbital flight, we could now have extensive operations on the easiest to reach nearby destinations: Earth’s moon, Earth-approaching asteroids, and the Martian moons. This ongoing activity may have provided the markets needed for private investment in better transportation.

When the last three approved Apollo flights were canceled, we were already on a steep learning curve. Compare the one day visit of Apollo-11 to the detailed geology and exploration done on Apollo-17, only six successful missions later. The Saturn infrastructure was also on steep cost decline as production lessons were being absorbed and implemented.

Everyone interested in these issues should read Exploring the Moon: the Apollo expeditions by David M. Hartland, especially the section on Apollo-16. This excellent book covers the geology that was attempted by the last three Apollo missions and reads like a novel of exploration. Even I was surprised at the extent and detail of the field geology undertaken, and by the capabilities of the astronauts to quickly travel and sample across entire “alpine” valleys, even under the severe operational constraints of these first-generation human missions. The key lesson of Apollo-16 is that expectations from both remote observation and automated probes turned out to be dead wrong, and a whole new theory of geological processes no longer extant on Earth was developed because of the Apollo-16 crew's discoveries (semi-fluid brecciating flow from an impact creating a fill that from a distance looks like remarkably like lava fill).

The geology of regolith and breccia's is the geology that most likely dominates the inner Solar System (and, indeed, the inner regions of most star systems). As such, it deserves great study. Mr. Hartland demonstrates that the commonly accepted view that the geology and surface of the moon are boring, is simply wrong. I think this view results partly because the geologic traverses done during the Apollo missions were largely ignored at the time. People were more interested in the success of actually getting there, and scientists wanted to hare off to Mars. This wide-spread ignorance of what Apollo actually accomplished and what the moon is really like resulted in a great distortion in our perception of the relative value of human exploration versus robotics. That, in turn, has damaged our space program ever since as we continue to convince ourselves that science can be automated. At the risk of over-stating my case, I'll argue that, today, here and now, sending geologists to the extraordinarily accessible moon is probably the best way to teach us about the processes creating the surfaces of most worlds throughout much of the galaxy.

The science that continuing Apollo would have achieved includes, but is not limited to, the following.

Combine all this with its accessibility, and I think there is an excellent case for returning to Earth's moon and conducting detailed exploration before we get ahead of ourselves haring across the Solar System with robots. Doing the latter has given us great information about the easy stuff and the surfaces -- reconnaissance -- but in the long-term, our successes have probably done us a disservice. The history of science is replete with the wrong conclusions being drawn because you took a quick-and-dirty look at broad areas while failing to take a detailed look at the sites you can reach.

With Apollo, we could reach the moon. We could do detailed geology of a type that we cannot do anywhere else for decades to come. That's what we should have been doing, and it is what we should be doing now. It would be most valuable done with continued automated reconnaissance of the rest of the Solar System, but if you have to choose, you should do the former before you do the latter.

What technology exists right now that you think has the most underrated potential?

Without question, solar sails. Like on Earth, sailing is virtually free transportation. Why everyone insists on ignoring this obvious technique is beyond me.

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