A Biomechanical Design Framework to Improve Spacesuit Boot Fit

Abstract

The current trace contaminant control subassembly (TCCS) aboard the International Space Station (ISS) includes a packed bed containing Barnebey-Sutcliffe Type 3032 (BS-3032) activated carbon to control ammonia levels in cabin air. The activated carbon encounters trace amounts of volatile organic compounds (VOCs) which enter the cabin through material offgassing, human metabolism, and crew activities. As part of an effort to address BS-3032 commercial obsolescence, two candidate replacements—Ammonasorb II and Chemsorb 1425—were tested in the presence of VOCs to examine the effects of these compounds on ammonia adsorption capacity. Gas streams containing acetone, ethanol, toluene and ammonia were generated to challenge each sorbent at 40% relative humidity (RH) and 23°C. These ersatz mixtures were delivered to test beds at two flow rates, a key parameter affecting mass transfer kinetics. Results were compared to previous pure component tests using only ammonia. The presence of VOCs decreased adsorption capacity of Ammonasorb II, especially at low flow rates, and had no effect on Chemsorb 1425 capacity at either flow rate.