Mechanical counterpressure suit
[1] The human body can briefly survive exposure to the hard vacuum of space unprotected,[2] despite contrary depictions in some popular science fiction.
Human flesh expands to about twice its size in such conditions, giving the visual effect of a body builder rather than an overfilled balloon.
[4][2] Cooling of the astronaut with an SAS is generally achieved with evaporation from body perspiration which is emitted from the suit in all directions.
In 1959 Hans Mauch was working on "breathable" undergarments for the Mercury space suit when he came up with the idea of a way to build a mechanical counterpressure design.
[5] Extended vacuum testing was carried out successfully, but the suit proved to have less mobility than expected and further development was dropped.
Between 1968 and 1971 ten designs of increasing sophistication were built, leading eventually to a series of successful tests in vacuum chambers.
Tests of punctures showed that up to a square millimeter of skin could be directly exposed to vacuum for extended periods with no permanent effect.
Concavities or small folds in the fabric could lead to fluid pooling in the gaps; the groin area proved extremely difficult to tailor successfully.
In order to effectively provide the minimum pressure of 0.3 bars (4.4 psi) necessary for human physiology, the suit had to be extremely tight-fitting, making donning and doffing a highly strenuous task.
Quoting the Report: In conclusion, the SAS at its present stage of development will protect man from the effects of the vacuum environment, in a garment, which permits improved mobility and natural body movements.
The helmet was secured by means of a non-elastic garment of Nomex cloth which wrapped around the chest and under the arms, and by the elastic layers above and below it.
As of 2005, the Bio-Suit team had constructed at least three lower leg prototypes using different materials, including nylon-spandex, elastic, and urethane-painted foam.
Each suit has to be custom tailored for the wearer, but the complexity of this task is reduced through the use of whole-body laser scans.
[15] Writers including Dan Simmons, Stephen Baxter, Larry Niven, and Spider and Jeanne Robinson have made use of space activity suits in their stories.
The potential for greater mobility and simpler operation with a space activity suit make it an attractive choice for fiction, where flexibility of use can be a boon to plot development.
The aesthetic qualities of a sleek, form-fitting space activity suit also contrast the traditional image of rigid, diving-suit-style spacesuits, lending a futuristic look to costumes.
Most anime with futuristic themes include the skintight spacesuit (with the notable exception of Planetes and, to a lesser extent, the Gundam franchise).
In the Mars trilogy by Kim Stanley Robinson, a suit similar to this is referred to as a "walker" and is intended purely for use in the Martian environment.
In the fourth book of the Jumper series by Steven Gould, the development of a mechanical counterpressure suit is integral to the main plot.
