The Three-Mile Limit

			    Fred Ringwald
		   Florida Institute of Technology
    Pubished in Spaceflight, vol. 42, no. 8, p. 323 (August 2000).


There are definite advantages to teaching at Kennedy Space Center.  My
badge, issued to teach a class on the base, enabled me to get as close to
anyone is permitted to watch a Space Shuttle launch.  

I was sitting in a van, in the parking lot on the southeast side of the
Vehicle Assembly Building (VAB), just across from the press stands.  I had
a clear line of sight out of the window to Pad 39A, some three miles away.

This three-mile radius was defined in the 1960s, when Pad 39A and the VAB
were built for the giant Saturn 5 moon rockets.  It was chosen for safety:
the Saturn V had the explosive potential of a small nuclear bomb.  Three
miles might seem a long way.  It turns out it was barely enough: during
the first flight of a Saturn 5, the Apollo 4 test in November 1967, the
noise was so loud it tore the roof off the press building.

Now I can see why.  From three miles, the Space Shuttle was so loud, it
left my ears ringing afterwards for about an hour.  It was easily as loud
as a jackhammer.  Hearing wasn't the only sense jarred: I was watching
through 11 x 80 binoculars, at 6:11 a.m., just before sunrise at 6:29.
When the Shuttle cleared the pad, the flames from the Solid Rocket
Boosters were so bright, my pupils contracted enough to make the
background sky look no longer blue, but black.

The most vivid sensory assault, though, was touch.  All rockets make a
deep, low-frequency rumbling, a, unearthly sound, more felt than heard.
The Shuttle is no exception, but imagine this outclassing the sound of a
jackhammer.

I put my hand outside the open window of the van, from which I was
watching, and tried to hold the binoculars steady.  This was impossible,
because the whole door of the van was shaking vigorously, along with the
whole van.  The solid fuel burns unevenly, in lumps, which made a most
distinctive shaking.  Astronauts say it feels like a rough train ride, and
now I see it must be very rough indeed.

I noticed the crowd did not applaud until SRB separation: I could not have
heard them earlier anyway.  As the Shuttle rose into the dawn sky, its
sky-blue pink made pretty colors in the exhaust contrail.

Now I can see the reason for the three-mile limit: that is as close as
anyone in their right mind would want to be.  A Shuttle launch from that
close reminded me of a total solar eclipse or the Grand Canyon: one of
those things one simply must experience for oneself.  Altogether a morning
well spent!