The first half of Paul Spudis' book recapitulates
much of the geologic history and information presented
in Don Wilhelm's To a Rocky Moon,
supplemented by data from the 1994 Clementine mission in which Spudis
played an important part. The Clementine data is quite
interesting and this book presents several intriguing graphics
on surface topography and mineral distribution. Clementine
provided our best view yet of the South Pole-Aitken basin
which descends as much as 12 km below the mean surface - it also
discovered the near-perpetually sunlit crater rim in the South
Pole region that is tempting as a first lunar base location;
the book provides the interesting datum that the temperature at
that point is stable and more human-friendly than elsewhere on
the Moon's surface, around -30 to -50 degrees Celsius.
The second (future) half of "The Once and Future Moon" addresses
why, how, and when we will return to the Moon. Spudis' experiences
with Clementine, and the negative experience with the big-budget
NASA-planned Space Exploration Initiative (SEI - the $500 billion
plan to go back to the Moon and beyond)
of the early 1990's play an important part here.
The book emphasizes a "pay as you go" small-scale approach
to getting back. Cutting the cost of going to space is clearly
needed - Spudis was perhaps over-optimistic about the DC-X, but mentions
several other alternatives that might do just as well, and clearly examines
where the current launch costs arise (hint: the energy to get to orbit
costs a lot less than all those salaries for human hangers-on).
Once we can feasibly do it, getting back to the Moon should proceed in phased
steps. First orbiters to do more geological surveying (and
provide telecommunication or other services). Then landers which may
be capable of scientific research activities (astronomical observatories
may be a good early candidate) but also to perform construction,
manufacturing, or chemical processing to start the necessary use
of in-situ resources. Rovers make sense as a next step, to explore
more of the surface at a field-geological scale, and to facilitate
construction of various services (energy, roads, etc.) Finally
human bases will be needed to perform all those tasks requiring
human dexterity, flexibility, and on-site decision-making, as the
lunar infrastructure continues to grow.
Spudis' appendixes review the basic lunar facts and missions; most
of this is also in Don Wilhelms' book. Spudis also provides
a valuable bibliography with commentary on a large selection of
books and other materials.
As a shorter book than Wilhelms', this is a good introduction to
lunar geology (in the first half) and goes much beyond it in the
second half discussing where we go from here. Spudis seems hopeful;
read this book and you might almost be convinced that we'll really
be back there soon!