BKMONFAL.RVW   990612

"Moonfall", Jack McDevitt, 1998, 0-06-105112-8, U$6.50/C$8.50
%A   Jack McDevitt
%C   10 East 53rd Street, New York, NY  10022-5299
%D   1998
%G   0-06-105112-8
%I   HarperCollins/Basic Books
%O   U$6.50/C$8.50 fax: 212-207-7433 fax: 212-207-7222
%P   544 p.
%T   "Moonfall"

Watch out!  It's a comet, come to wipe out ... no, not the earth. 
Just the moon.  Then bits of the *moon* wipe out the earth.

Wonderfully sympathetic characters.  Interesting twist on an old
premise.  A bit *too* much tension: by the time the hero survives the
cataclysm you begin to wonder why half the book is left, and by the
end you are almost willing for everyone to die, just so long as the
darn thing finishes!  (Along the way a few too many of the plot twists
are telegraphed well in advance: not a lot come as any surprise when
they do show up.)

An awful lot of people from NASA and other space institutions get
thanked.  In many areas careful research is evident.  A number of
astronomical, astrophysical, and cosmological facts are presented
correctly.  Readers of the RISKS-FORUM Digest would be quite happy
with the fact that it is small errors, in combination, that create the
biggest problems.  However, when the plot action starts happening, all
the careful research goes out the window.

A major factor in the plot are a number of "single stage to orbit"
spaceplanes.  The space station seems to have an inexhaustible supply
of fuel for them.  However, the idea behind an SSTO is that while it
uses a huge amount of fuel to get up, it needs almost nothing coming
down.  There just wouldn't be any reason to have that much fuel on
hand.

Now, despite what "BattleStar Galactica," "Starship Troopers," and
other quality training materials may show you, fireballs do not
billow, nor do clouds roll, in the vacuum of space.  Absent the fairly
minor curvatures imposed by gravity, and the effect of the odd
collision, everything in space moves in pretty straight lines,
including light, hot gases, and rocks of whatever size.  Shockwave
"fronts" do not exist in space.  Dodging debris would be a zero sum
game, since unless every piece had the same velocity, in which case
matching speed once would take care of everything, decreasing your
delta-V with respect to one chunk would tend to increase it with
respect to something else.

Also, having achieved the relative safety of earth orbit in concert
with some of the bits that were going your way would give scant
relief: shortly you would round the earth and start heading into a
bunch of stuff going the other direction.  Orbital dynamics is not a
real strong point in this book.  The biggest error, though, is granted
to the biggest piece of rock.  POSsible IMpactor number 38, dubbed
Possum in the book, makes two very exciting passes on an elliptic
orbit around the earth.  The first one is definitely east to west,
while orbit two is west to east ...

copyright Robert M. Slade, 1999   BKMONFAL.RVW   990612