Pressure suit

Maintaining constant gas pressure as the wearer moves is difficult, because the internal volume of a simple construction inflatable suit will change when body joints are flexed.

The ribbed structures are usually braced with wire cables or cloth straps to limit their motion and prevent unusual flexing modes that may chafe against the user's body.

The wire hinge cables also restrain the complex folds, which if released could unfurl and extend to be more than a meter longer than the wearer's body.

[citation needed] The human body can briefly survive the hard vacuum of space unprotected, despite contrary depictions in much popular science fiction.

Human flesh expands to about twice its size in such conditions, giving the visual effect of a body builder[citation needed] rather than an overfilled balloon.

No snap freeze effect occurs because all heat must be lost through thermal radiation or the evaporation of liquids, and the blood does not boil because it remains pressurized within the body.

The CH-1 was a simple pressure-tight suit with a helmet which did not have joints, thus requiring substantial force to move the arms and legs when pressurised.

Recognizing that the flight would require specialised protective clothing, he visited the UK in 1933 where he met with Scottish physiologist John Scott Haldane, who had published a concept for a fabric full pressure suit in the 1920s.

Swain of the Royal Air Force set the official world altitude record at 49,967 feet in a Bristol Type 138 wearing a similar suit.

[9] In 1934, aviator Wiley Post, working with Russell S. Colley of the B.F. Goodrich Company, produced the world's first practical pressure suit.

Attached to the frame were pigskin gloves, rubber boots, and an aluminum and plastic helmet with a removable faceplate that could accommodate earphones and a throat microphone.

No effective fully mobile pressure suits were produced in World War II but the effort provided a valuable basis for later development.

The David Clark Company supplied technical support and resources, and a prototype suit was tested to a simulated 90,000 feet at Wright Field in 1946.

[10] The RAF Institute of Aviation Medicine and the Royal Aircraft Establishment developed a partial-pressure helmet which was used with a capstan type suit purchased from the US.

It was worn by Walter Gibb and his navigator to set a world altitude record on 29 August 1955 in an English Electric Canberra.

The RAF never issued a partial-pressure suit, preferring instead to use anti-g trousers in conjunction with pressure jerkins (which applied mechanical counter-pressure to the wearer's chest).

A U-2 pilot suit
An indirect-compression pressure suit without the exterior ballistic covering, showing the many complex fabric folds, internal fold support rings, and flexible stacked cable hinge assemblies of constant-volume flexible joints.
Showing the functional components of a direct-compression capstan anti-G pressure suit: A - inflation hose connection to external air supply, B - flexible elastic tube contained inside an inelastic fabric tunnel along the length of a limb, C - alternating fabric bands to compress suit when capstan inflates, D - laced folds for customizing the fit of the fabric suit to tightly match the wearer's anatomy.
Italian aviator Mario Pezzi in his high-altitude pressure suit, circa 1937
Joe Walker in an early Air Force partial pressure suit
Astronaut Gordon Cooper in helmet and pressure suit