Navy Mk 4 Suit
Status: operational 1958.
By the early 1960s, the US Navy had progressed through a series of developmental models of the full pressure suit that would ultimately take final form in the Mark IV, Model 3, Type 1.
Regardless of the success of the A/P22S-2 suit and its modifications in Air Force use, it remained to the US Navy's cooperative program with the B. F. Goodrich Company and pioneer suit designer Russell Colley to solve some important problems concerning mobility and full pressurization. One of the most important developments was an aneroid suit controller that maintained suit internal pressurization at precisely 0.24 bar. The Mark series of US Navy full pressure suits which followed culminated in three models of the final Mark IV suit, which went into production in 1958 as standard high altitude issue for US Navy squadrons. The Mark IV, Model 3, Type 1 suit featured various enhancements in fit and ease of donning, as well as substantially improved pressurization control. It would go on to be selected as the basic foundation for modification into NASA's early earth-orbital suit (the original Mercury prototype suits were specially reworked Mark IV suits).
|Mercury Space Suit American space suit, operational 1960. The Mercury spacesuit was a custom-fitted, modified version of the Goodrich U.S. Navy Mark IV high altitude jet aircraft pressure suit.|
|A/P 22S-3 American pressure suit, operational 1960. USAF version of the USN Mark IV suit (B. F. Goodrich and Arrow Rubber Company). Full pressure, two layers, oxygen regulator exterior of helmet, 12 torso sizes, 7 gloves sizes, 2 helmet sizes.|
The B. F. Goodrich Company was selected as the contractor to design and develop the Mercury astronaut pressure suit. Company technology in this field dated back to 1934, when it developed the first rubber stratosphere flying suit for attempts at setting altitude records.
Between November 1959 and January 1960, 10 developmental Mercury full-pressure suits were delivered. These suits were used in various Mercury training and development programs. Several problem areas were denoted. One involved stretching which complicated the suit mobility problem. This matter was being investigated, and one of the solutions was felt to be undersizing to allow for a suit growth factor. In addition, modifications would have to be made in suit insulation to provide for better pilot mobility. These problems were to be expected in a developmental program.
The astronauts and medical personnel who had tested the developmental suits received in November 1959 recommended a number of changes to increase the physical mobility of the astronaut before the production effort began. Evaluation of the test suits with the suggested modifications indicated that the mobility and suit-spacecraft compatibility had been greatly enhanced. The stretching which once had been a problem area had been significantly decreased.
Development of an advanced state-of-the-art pressure suit and helmet was started. This action was taken in preparation for the Mercury extended range or 1-day mission program. The objectives were aimed at improvements in unpressurized suit comfort, suit ventilation, pressure suit mobility, electrically heated helmet visor with additional light attenuation features, and the fabrication of a mechanical visor seal mechanism.