as a result, the suit ruptured between the
torso and legs.
A metal clamp was added between the
torso and legs in the redesigned pressure suit.
Post again donned the suit for its pressure test.
This test took place on a hot day and before
long, Post began suffering from the heat. But,
the suit was so tight that Post couldn’t remove
it. To get Post out of the suit, B.F. Goodrich
engineers began cutting him out of it. The
tightness of the suit made this a long and
difficult procedure, so Post was moved to a
refrigerated golf ball storage room where he
could remain cool while he was carefully cut
out of the suit.
Additional modifications were made to the
third design. The third suit had a larger neck
opening to make it easier to get into and out
of the suit. It was assembled in the seated
position so Post wouldn’t have to exert effort
just to remain seated in the aircraft. Metal rings
were molded into the suit above and below joints like the knees and
the fabric was then bunched up between the rings to make the joints
more flexible. The suit’s pressure gauge plugged into the knee and a
bottle of liquid oxygen was used to pressurize the suit. Testing showed
that Post finally had a functional pressure suit.
Post flew to an altitude of 50,000 feet wearing the suit. Unfortunately, one of the official barometers onboard the airplane failed, so
the flight didn’t qualify for the record. Upon landing at Murdoc dry
lakebed, Post exited his airplane and asked a
stranger for help removing the helmet. The
wind sail car enthusiast almost passed out from
the sight of Post in this pressure suit (think of
a similar scene from the movie, Back To The
Willey Post’s pressure suit worked, but it
was too uncomfortable to wear for long
periods of time. When pressurized, the suit was
so stiff that it made operating the airplane
difficult. An improved method for increasing
the flexibility of the pressure suit was required.
To understand the challenges that
pressure suit designers face, get a long and
narrow balloon. Try bending the balloon before
filling it with air. Now fill the balloon with air
and try bending it again. The more you fill the
balloon, the more difficult it is to bend. This is
the problem pilots are up against, except every joint of their body is
being restrained from bending.
Balloons resist being bent because, as you bend them, you’re
decreasing their volume and increasing their internal air pressure.
When you bend an inflated balloon you’re not working against the
rubber skin of the balloon, you’re working against the balloon’s
internal pressure. You can vent some of the balloon’s air to make it
easier to bend. In fact, this is just what cosmonaut Alexei Leonov
did to get back into the airlock of the Voskhod 2 space capsule.
However, this is a very dangerous way to solve the bending problem
of a pressure suit.
Tomato worms are up against the same bending problem. They
have long and narrow bodies that are internally pressurized. The way
evolution solved this problem was to add accordion-like ridges or pleats
to their bodies. The next generation of pressure suits took a clue from
the tomato worm and added accordion-like ridges around the areas
where the suit needed to bend, like the knees and elbows.
■ MERCURY MISSION
THE MILITARY FULL
AND PARTIAL PRESSURE SUIT
With the advent of high-altitude high-speed jet flight, a new requirement emerged. During high G-maneuvers, pilots risked blacking
out when blood left their brain and collected in their torso, arms, and
legs. So now, pilots needed protection from the accidental depressurization of the cockpit, as well as help flying high G-maneuvers.
Tight fitting clothing can be used to press against the body and
force blood back into the brain during high G-maneuvers. A bladder
sewn into the chest and tubes sewn into the outsides of the arms and
legs would fill with air and pull the loose suit tightly against the pilot’s
body, but under normal flying conditions the clothing would be loose
and comfortable. These suits are called G-suits. The first example was
the S-1, which was developed by the University of Southern California
in support of the X-1 program.
The David Clark Company modified the S-1 into the T-1 by combining a G-suit with the partial pressure suit. In the partial pressure suit,
air pressure is only maintained around the pilot’s face. The rest of the
body only experiences pressure through the constriction of the suit. A
tight facemask and neck seal kept pressurized oxygen from leaking out
of the mask. It was the T-1 that the early test pilots, such as Chuck
70 NUTS & VOLTS November 2005