NASA’s planned return to the Moon is the most exciting proposed development in human spaceflight in a generation, and it promises to be a 21st century bonanza for the space sciences.
As designed by NASA Administrator Mike Griffin and his team, America’s return to the Moon offers to be both affordable and technologically low risk. With their recently released plan, Griffin & Co. have simultaneously provided both a breath of fresh air for the future of human spaceflight, and the opening salvo of what will hopefully lead humankind to epic, in-person explorations of the canyons of Mars, the ore deposits of near- Earth asteroids and hopefully someday to the ice-fields of the outer solar system. Indeed, with luck, pluck and perseverance, the return to the Moon will serve as a much-needed precursor to enable more distant journeys where no one has gone before.
Several good motivations for returning to the Moon have been cogently made by politicians and space pundits alike. These include a more worthy basis for risking the lives of astronauts than the shuttle ever provided: gaining the operational experience needed to push on to far-away destinations like Mars and the continued demonstration of American leadership in an increasingly competitive human spaceflight arena.
However, the scientific value of the impeding return of humans to the Moon too often has been overlooked. A powerful empirical demonstration of the value of the Moon for science is in the great scientific paradigm shifts that Apollo provided. Despite being limited to six simple forays, Apollo sampling expeditions were responsible for spawning both the giant impact formation paradigm of the Earth-Moon pair, and the broadly accepted insight that a wave of cataclysmic planetary bombardment very likely sparked by far-away events in the outer solar system (the so-called Late Heavy Bombardment ) pummeled the Moon and the inner planets some 700 million years after Earth formed.
Griffin’s planned return to the Moon offers far more sophisticated and far more in-depth lunar exploration than Apollo could ever have delivered. Imagine what we will know when not six, but 16 and then 60 lunar sites have been sampled. Imagine the value of core samples drilled not three meters deep as in Apollo, but 30, 300 and then 3,000 meters deep.
Likewise, taking advantage of the half century of advances between Apollo and its 21st century successor, one can only imagine the power that modern seismic profiling and tomography, super-sensitive interior out-gassing products analysis, subsurface radar imaging and so many other techniques can bring to the table of lunar research.
Between the in situ studies to be performed on the Moon and the treasure trove of returned samples one can anticipate, it is easy to envision benefits for planetary research that likely will include:
– “Poor man’s” cometary sampling made possible by studies of returned polar volatiles emplaced by ancient cometary impacts;
– The return of a treasure trove of ancient terrestrial meteorites yielding otherwise unobtainable samples of the early Earth that long ago were cast up to the safe haven of the lunar surface;
– A far better understanding of the time variation of impact hazards to Earth, thanks to the age dating of numerous cometary and asteroidal bombardment craters; and,
– A deep understanding of the evolution of the Moon’s geological, thermal and chemical evolution, which will illuminate results that robotic missions will return at bodies as diverse as Mercury, Ceres, Vesta and Venus.
This list is certainly only a primitive foreshadowing of the planetary science that can be achieved by an extensive series of landings across the Moon, the emplacement of an Antarctic-style outpost and a diverse array of research stations there like the Apollo Lunar Surface Experiments Packages .
But the scientific yield of the planned return to the Moon will not be limited to planetary science alone. Astronomical research should benefit if the lunar return can be leveraged into the erection of facilities like a far side radio telescope. Space biology, too, will benefit through studies of both radiation effects and the first long-term studies of low-gravity effects on organisms. And both Earth science and Sun-Earth connection studies should benefit extensively from the return of samples yielding a detailed history of solar and galactic cosmic ray fluxes, nearby supernovae, and Earth’s passages through the dust lanes and dark molecular clouds of the Milky Way.
And lest we forget, like the entirely unexpected Apollo-era discoveries of late heavy bombardment and that a giant impact on Earth was responsible for the formation of the Moon, the greatest discoveries of renewed lunar expeditionary missions may be ones we cannot even anticipate today.
Griffin & Co.’s return to the Moon holds deep promise for science, just as it does for national pride, international prestige and preparing the way for historic explorations farther afield.
Let us carry this story forward boldly as yet another banner of motivation to enable America’s too-long delayed return to the Moon.
S. Alan Stern is a planetary scientist and executive director of the Space Science and Engineering Division of the Southwest Research Institute.
