Mercury Suit Credit - NASA

The Mercury spacesuit was a custom-fitted, modified version of the Goodrich U.S. Navy Mark IV high altitude jet aircraft pressure suit. It consisted of an inner layer of Neoprene-coated nylon fabric and a restraint outer layer of aluminized nylon. Joint mobility at the elbow and knees was provided by simple fabric break lines sewn into the suit; but even with these break lines, it was difficult for a pilot to bend his arms or legs against the force of a pressurized suit. As an elbow or knee joint was bent, the suit joints folded in on themselves reducing suit internal volume and increasing pressure.

The Mercury suit was worn "soft" or unpressurized and served only as a backup for possible spacecraft cabin pressure loss - an event that never happened. Limited pressurized mobility would have been a minor inconvenience in the small Mercury spacecraft cabin. The Mark IV, Model 3, Type 1 suit from which it was derived featured various enhancements in fit and ease of donning, as well as substantially improved pressurization control. The original Mercury prototype suits were specially-reworked Mark IV suits (NASA designated them XN-1 through XN-4 models, but they were referred to by engineers as the "quick fix" suits).

• 1959 January 1 - Development of the Mercury pressure suit was started. - Program: Mercury.

• 1959 July 1 - Mercury pressure suit compatibility evaluation. - Program: Mercury.

  A pressure suit compatibility evaluation in the Mercury spacecraft mock-up was performed in suits submitted by the David Clark Company, B. F. Goodrich Company, and International Latex Company. Four subjects participated in the tests.

• 1959 July 22 - Goodrich selected for the Mercury astronaut pressure suit - Program: Mercury.

  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.

• 1959 March 16 - Purchase of five developmental pressure suits for Project Mercury. - Program: Mercury.

  Purchase approval in the amount of $125,000 was requested by the Space Task Group from NASA Headquarters for the procurement of five developmental pressure suits for Project Mercury.

• 1959 November 1 - Mercury first manned development system tests - Program: Mercury.

  The first manned development system tests were completed at the AiResearch Manufacturing Division, Garrett Corporation. Tests were conducted in the altitude chamber to determine proper functioning of all system valves and components. A McDonnell subject was clothed in a Mercury-type presure suit for these tests. Preliminary data from these tests indicated that the system functioned satisfactorily.

• 1959 November 1 - Mercury full-pressure suits delivered. - Program: Mercury.

  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.

• 1959 November 16 - Mercury astronauts familiarized with the expected reentry heat pulse - Program: Mercury.

  Wearing the Mercury pressure suits, the astronauts were familiarized with the expected reentry heat pulse at the Navy Aircrew Equipment Laboratory, Philadelphia, Pennsylvania.

• 1959 November 5 - Mercury astronauts fitted with pressure suits. - Program: Mercury.

  The astronauts were fitted with pressure suits and indoctrinated as to use at the B. F. Goodrich Company, Akron, Ohio.

• 1959 October 2 - Specifications for the Mercury pressure suit were issued. - Program: Mercury.

  The suit procurement program was divided into two phases: Phase I, operational research suits which could be used for astronaut training, system evaluation, and further suit development; and Phase II, Mercury pressure suits in the final configuration.

• 1960 June 20 - Manned tests of the Mercury environmental control system began. - Program: Mercury.

  The subjects were clothed in pressure suits and subjected to postlanding conditions for 12 hours without serious physiological effects. The purpose of this test was to evaluate human tolerance, and the results indicated that no modification to the system were necessary. However, the postlanding ventilation conditions would continue to be monitored and requirements for any modifications would be evaluated.

• 1960 May 1 - Production of the manned space flight configuration of the Mercury pressure suit was started. - Program: Mercury.

  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.

• 1960 October 3 - Third Mercury centrifuge training program - Program: Mercury. Flight: Mercury MR-3.

  The third Mercury centrifuge training program was conducted for the astronauts at the Aviation Medical Acceleration Laboratory. Additional Details: Third Mercury centrifuge training program (23418).

• 1960 September 1 - Flight-type Mercury pressure suits received from Goodrich - Program: Mercury.

  Flight-type pressure suits were received from the B. F. Goodrich Company and were immediately used on the human centrifuge to assist in determining final adjustments that were necessary in preparation for manned space flight.

• 1962 April 1 - Development of an advanced Mercury suit started. - Program: Mercury. Flight: Mercury MA-9, Mercury MA-10, Mercury MA-11, Mercury MA-12.

  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.

• 1962 July 13 - B-70 Valkyrie harness.tests for Mercury - Program: Mercury.

  Tests were conducted with a subject wearing a Mercury pressure suit in a modified Mercury spacecraft couch equipped with a B-70 (Valkyrie) harness. When this harness appeared to offer advantages over the existing Mercury harness, plans were made for further evaluation in spacecraft tests.

• 1962 November 13 - Tinted visor for the Mercury helmet - Program: Mercury.

  The B. F. Goodrich Company reported that it had successfully designed, fabricated, and tested a pivoted light attenuation tinted visor to be mounted on a government-issued Mercury helmet.

• 1963 April 30 - Improvements to the Mercury pressure suit for Mercury MA-9 - Program: Mercury. Flight: Mercury MA-9. Launch Vehicle: Atlas D.

  A number of improvements had been made to the Mercury pressure suit for the Mercury-Atlas 9 (MA-9) flight. Additional Details: Improvements to the Mercury pressure suit for Mercury MA-9 (23739).

• Grimwood, James M., Project Mercury: A Chronology, NASA Special Publication-4001.