The Partial Pressure of Inspired Carbon Dioxide Exposure Levels in the Extravehicular Mobility Unit.

NASA has been making efforts to assess the carbon dioxide (CO₂) washout capability of spacesuits using a standard CO₂ sampling protocol. This study established the methodology for determining the partial pressure of inspired CO₂ (Pco₂) in a pressurized spacesuit. We applied the methodology to characterize Pco₂ for the extravehicular mobility unit (EMU).

Carbon Monoxide Levels in the Extravehicular Mobility Unit by Modeling and Operational Testing.

Carbon monoxide (CO) is a toxic gas with potential for detriment to spaceflight operations. An analytical model was developed to investigate if a maximum CO contamination of 1 ppm in the oxygen (O₂) supply reached dangerous levels during extravehicular activity (EVA). Occupational monitoring pre- and postsuited exposures provided supplementary data for review.

A Systematic Review and Meta-Analysis of Decompression Sickness in Altitude Physiological Training.

A review of decompression sickness (DCS) cases associated with the NASA altitude physiological training (APT) program at the Johnson Space Center (JSC) motivated us to place our findings into the larger context of DCS prevalence from other APT centers. We reviewed JSC records from 1999 to 2016 and 14 publications from 1968 to 2004 about DCS prevalence in other APT programs. We performed a meta-analysis of 15 APT profiles (488 cases / 385,116 exposures).

Hemoglobin Oxygen Saturation with Mild Hypoxia and Microgravity.

Introduction: Microgravity (μG) exposure and even early recovery from μG in combination with mild hypoxia may increase the alveolar-arterial oxygen (O2) partial pressure gradient.

Methods: Four male astronauts on STS-69 (1995) and four on STS-72 (1996) were exposed on Earth to an acute sequential hypoxic challenge by breathing for 4 min 18.0%, 14.

Venous Gas Emboli and Ambulation at 4.3 psia.

Introduction: Ambulation during extravehicular activity on Mars may increase the risk of decompression sickness through enhanced bubble formation in the lower body.

Hypotheses: walking effort (ambulation) before an exercise-enhanced denitrogenation (prebreathe) protocol at 14.7 psia does not increase the incidence of venous gas emboli (VGE) at 4.