- Hall, R. Cargill.
Lunar Impact.
Washington: National Aeronautics and Space Administration, 1977.
ISBN 978-0-486-47757-2. NASA SP-4210.
-
One of the wonderful things about the emergence of electronic
books is that long out-of-print works from publishers'
back-lists are becoming available once again since the cost
of keeping them in print, after the initial conversion to an
electronic format, is essentially zero. The U.S. civilian
space agency NASA is to be commended for their efforts to
make publications in their NASA history series available
electronically at a bargain price. Many of these documents,
chronicling the early days of space exploration from a perspective
only a few years after the events, have been out of print for
decades and some command forbidding prices on used book markets.
Those interested in reading them, as opposed to collectors, now
have an option as inexpensive as it is convenient to put these
works in their hands.
The present volume, originally published in 1977, chronicles
Project Ranger,
NASA's first attempt to obtain “ground truth” about
the surface of the Moon by sending probes to crash on its surface,
radioing back high-resolution pictures, measuring
its composition, and hard-landing scientific instruments on the
surface to study the Moon's geology. When the project was
begun in 1959, it was breathtakingly ambitious—so much
so that one gets the sense those who set its goals did not
fully appreciate the difficulty of accomplishing them. Ranger
was to be not just a purpose-built lunar probe, but rather a
general-purpose “bus” for lunar and planetary missions
which could be equipped with different scientific instruments
depending upon the destination and goals of the flight. It would
incorporate, for the first time in a deep space mission,
three-axis stabilisation, a steerable high-gain antenna, midcourse
and terminal trajectory correction, an onboard (albeit extremely
primitive) computer, real-time transmission of television
imagery, support by a global
Deep Space Network
of tracking stations which did not exist before Ranger, sterilisation
of the spacecraft to protect against contamination of celestial bodies
by terrestrial organisms, and a retro-rocket and landing capsule which
would allow rudimentary scientific instruments to survive thumping
down on the Moon and transmit their results back to Earth.
This was a great deal to bite off, and as those charged with delivering
upon these lofty goals discovered, extremely difficult to chew,
especially in a period where NASA was still in the process of
organising itself and lines of authority among NASA Headquarters,
the Jet Propulsion Laboratory (charged with developing the
spacecraft and conducting the missions) and the Air Force (which
provided the
Atlas-Agena
launch vehicle that propelled Ranger to the Moon) were
ill-defined and shifting frequently. This, along with the
inherent difficulty of what was being attempted, contributed to
results which can scarcely be imagined in an era of
super-conservative mission design: six consecutive failures
between 1961 and 1964, with a wide variety of causes. Even in
the early days of spaceflight, this was enough to get the
attention of the press, politicians, and public, and it
was highly probable that had
Ranger 7
also failed, it would be the end of the program.
But it didn't—de-scoped to just a camera platform,
it performed flawlessly and provided the first close-up glimpse
of the Moon's surface. Rangers 8 and 9 followed, both complete
successes, with the latter relaying pictures “live from the Moon”
to televisions of viewers around the world. To this day I
recall seeing them and experiencing a sense of wonder which is
difficult to appreciate in our jaded age.
Project Ranger provided both the technology and experience
base used in the
Mariner
missions to Venus, Mars, and Mercury. While the scientific
results of Ranger were soon eclipsed by those of the
Surveyor
soft landers, it is unlikely that program would have succeeded
without learning the painful lessons from Ranger.
The electronic edition of this book appears to have been
created by scanning a print copy and running it through
an optical character recognition program, then performing
a spelling check and fixing errors it noted. However, no
close proofreading appears to have been done, so that
scanning errors which resulted in words in the spelling
dictionary were not corrected. This results in a number of
goofs in the text, some of which are humorous. My favourite
is the phrase “midcourse correction bum [burn]”
which occurs on several occasions. I imagine a dissipated
wino with his trembling finger quivering above a big red
“FIRE” button at a console at JPL. British
readers may…no, I'm not going there. Illustrations
from the original book are scanned and included as tiny thumbnails
which cannot be enlarged. This is adequate for head shots of
people, but for diagrams, charts, and photographs of hardware
and the lunar surface, next to useless. References to
endnotes in the text look like links but (at least reading
the Kindle edition on an iPad) do nothing. These minor flaws
do not seriously detract from the glimpse this work provides
of unmanned planetary exploration at its moment of creation
or the joy that this account is once again readily available.
Unlike many of the NASA history series, a paperback
reprint edition is available, published
by Dover. It is, however, much more expensive than the
electronic edition.
Update: Reader J. Peterson writes that a
free on-line
edition of this book is available on NASA's Web site,
in which the illustrations may be clicked to view
full-resolution images.
February 2012 