NASA 
ing modifications of deep-sea divers’ 
suits were used by World War II design- 
ers to develop suits that would protect 
the crewmen flying at high altitudes in 
unpressurized planes. Above about 
30,000 feet, a protective suit is neces- 
sary. The development of pressurized 
suits for use in high-altitude military 
aircraft continued throughout the 
1950s. With the elimination of pressure 
points (places where the suits rub 
against the body), the suits became 
more comfortable and mobile enough to 
permit the operation of aircraft controls. 
In 1958 the newly formed National 
Aeronautics and Space Administration 
(NASA) initiated Project Mercury, 
whose goal was to put manned space 
capsules into orbit around the earth. To 
attain this objective, suits and life-sup- 
port systems had to be developed that 
could be used for many hours at alti- 
tudes of more than 100 miles. 
The requirements for the Mercury 
spacesuit were similar to those for high- 
altitude military aircraft. The suit 
served as a backup to the space cap- 
sule’s pressurization system. It had to be 
comfortable when worn unpressurized 
for hours on end, but it did not have to 
provide much mobility because the 
Mercury astronauts remained seated in 
the capsule at all times. Since the suit 
was not meant to be used outside the 
capsule, it did not have to protect the 
astronauts from temperature extremes 
and the other hazards of space. 
The Project Mercury spacesuit was, 
in fact, two suits — one inside of, and 
attached to, another. The inner suit was 
made of rubber, and its purpose was to 
contain the gas — pure oxygen in this 
case — used to pressurize the suit, exactly 
as gas is contained within a balloon. Rub- 
ber, however, is highly elastic and, like a 
balloon, the inner suit expanded if it 
wasn’t restrained. That was the function 
of the outer suit, which was made of a 
heavy, synthetic canvaslike fabric and re- 
sembled a workman’s coveralls. 
The astronaut entered the spacesuit 
through a zippered opening. A helmet 
and gloves were then mechanically at- 
tached. A hose connected to the cap- 
sule’s life-support system supplied the 
astronaut with oxygen for breathing, 
and a second hose removed his expired 
carbon dioxide from the suit. The car- 
bon dioxide was extracted and the puri- 
fied gas was then recirculated. Any pro- 
tective suit will interfere to some degree 
with the mobility of the wearer. But the 
astronauts of Project Mercury and the 
early Gemini missions — our second 
manned space project — did not leave 
their capsules. Their suits were designed 
for use exclusively within a severely 
limited area and therefore did not need 
to be very flexible. 
The first American to venture outside 
a space capsule was astronaut Edward 
White during the flight of Gemini IV in 
June, 1965. This first so-called extrave- 
hicular activity, or EVA, was simply an 
experiment to demonstrate that astro- 
nauts can survive in space when given 
the proper protective equipment. White 
was connected to the Gemini capsule by 
an “umbilical cord” that supplied oxy- 
gen and communication lines. Problems 
that arose during White’s and succeed- 
ing Gemini EVAs indicated that more 
sophisticated suits and life-support sys- 
tems would be needed if astronauts were 
to perform useful work in space. 
When these early-model suits were 
Space suit, above, was designed in 
the early 1930s for American 
aviation daredevil Wiley Post. 
Contemporary prototype units, 
right, are the result of half 
a century of evolution. 
pressurized, moving about in them re- 
quired a great deal of physical effort. 
This not only tired the astronauts but 
also caused them to become overheated. 
There are two main reasons why ex- 
traordinary effort was required to move 
around in those suits. First was friction 
created between moving parts. Every 
time an elbow or knee was flexed, the 
rubberized inner suit rubbed against the 
Anthony Wolfl 
52 
