BY L. PAUL VERHAGE
THE WELL-DRESSED ASTRONAUT
TODAY’S SPACE SHUTTLE
SPACESUIT doesn’t make a good
spacesuit for planetary exploration
because of the differences between
working in weightlessness for a
single mission and working on a
dusty, gritty planet with gravity for
months on end.
■ A1C SUITS
To make a good planetary suit, the Space Shuttle spacesuit
would need to be easier to wear, clean, maintain, and personalize.
So with plans to go back to the Moon and then eventually to Mars,
astronauts need a new generation of spacesuit, the planetary suit.
The International Latex Corporation and the David Clark Company
are working with NASA to develop and test the technologies that
will go into tomorrow’s planetary suit. Before discussing some of
these technologies, let’s briefly look at the dangers of high altitude
SOME EARLY (AND BAD)
EXPERIENCES AT HIGH ALTITUDE
In 1862, aeronauts James Glaisher and Henry Coxwell made their
first scientific balloon flight to explore the high troposphere. By the time
they reached 30,000 feet, Glaisher had passed out due to the lack of air.
Both aeronauts would have died had Coxwell not opened the balloon’s
vent. The chilling cold made it impossible to use his hands, so Coxwell
used his teeth to pull the balloon vent open.
In 1927, Army Air Service Captain Hawthorne Gray made several
flights into the high troposphere. He did not wear a pressure suit but
did take an oxygen mask on his later flights. Gray made his last flight in
November of that year. His final log entry mentions how the cold air
was interfering with his ability to function. Gray was found at the end
of his flight, in a tree and slumped over in his opened gondola. The cause
of death is not certain, although it’s believed the lack of oxygen was
the primary factor.
68 NUTS & VOLTS November 2005
PROTECTING HUMAN LIFE
AT HIGH ALTITUDE
At first glance, you’d think that providing oxygen and warm
clothing would be enough to keep humans alive at high altitude.
Unfortunately, breathing at a lower pressure also means getting less
oxygen. Not even 100% oxygen is enough to keep a person alive once
the air pressure drops below about 0.7 pounds per square inch (PSI).
Forcing more oxygen into the lungs is not the solution. As little
as one PSI over pressure is enough to rupture the lungs. Needless to
say, with a pair of ruptured lungs it doesn’t matter how much oxygen
a person receives. So, along with getting enough oxygen in each breath
of air, pressure must be exerted against the torso to make breathing
A spacesuit must also protect the body from the other harmful
effects of low pressure. One effect is the release of nitrogen bubbles
from body fluids. This effect, called the bends, results in severe pain
and even death. Even if the bends are prevented, low air pressure can
create severe pain as the internal pressure of the body presses outward on the skin. A second effect of low air pressure is the lowering
of the boiling point of liquids. Above an altitude of 63,000 feet, the air
pressure is so low that body fluids like blood and saliva boil. If the bends
don’t kill you, boiling blood will.
Normally, when we exhale, the air dilutes the carbon dioxide in our
breath to safe levels. Breathing oxygen through a mask can
prevent this dilution. When carbon dioxide is not scrubbed from our breath,
its concentration in our blood builds up and, as a result, the cells in our