Criteria for design of the mercury environmental control system, method of operation and results of manned system operation. Aerosp Med 1961; 32:839-43.

摘要

In this classic paper, engineers from the McDonnell Aircraft Corporation presented a detailed description of the Mercury capsule's life support system before the first U.S. manned spaceflights. Fundamental design considerations included simplicity, redundancy, low weight, and critical delivery time requirements. For this reason, a decision was made early in the design process to use a low-pressure 100% O_2 atmosphere. This was considered necessary as it was less complex than a mixed gas cabin atmosphere, avoided high structural weight, and greatly decreased the cabin leakage rate. The disadvantage was that it made heat removal more difficult. It was also noted that the fire hazard greatly increased with the increase in the O_2 concentration. The physiological pO_2 cabin pressure limits at 100% O_2 were considered to be between 16,000 ft (412 mmHg) and 38,000 ft (155 mmHg). The final cabin atmosphere chosen was 27,000 ft (258 mmHg or 5.0 psi) as this would provide adequate oxygenation and enough barometric pressure to avoid decompression sickness.