A theoretical method for selecting space craft and space suit atmospheres

Area of Science:

• Physiology
• Aerospace Medicine
• Biotechnology

Background:

• Decompression sickness (DCS) is a risk for astronauts due to pressure changes.
• Existing decompression protocols may not fully mitigate DCS risk.
• Understanding gas bubble dynamics is crucial for astronaut safety.

Purpose of the Study:

• To develop a theoretical method for selecting optimal spacecraft and space suit atmospheres.
• To ensure astronaut safety during immediate decompression from sea level to station pressure.
• To evaluate factors influencing gas bubble formation and resolution.

Main Methods:

• A theoretical model assuming gas bubbles cause DCS when exceeding critical volume.
• Analysis of nitrogen equilibrium between lungs and tissues.
• Simulation of decompression scenarios for space station and shuttle missions.

Main Results:

• The proposed method allows immediate decompression from sea level to station pressure without preoxygenation.
• Decompression results in sub-critical gas bubbles that are subsequently absorbed.
• Exercise and incomplete nitrogen equilibrium increase bubble size, limiting certain decompression procedures.

Conclusions:

• The theoretical method provides a framework for selecting safe spacecraft and space suit atmospheres.
• It enables immediate decompression, enhancing operational flexibility for space missions.
• The findings highlight the importance of considering physiological factors in decompression strategy design.