Ensuring Astronaut Safety
Achieving safe exploration of space in vehicles that rely upon closed environmental systems to recycle air and water to sustain life and are operated in extremely remote locations is a major challenge. The Toxicology and Environmental Chemistry (TEC) group at Johnson Space Center (JSC) is made up of 2 interrelated groups: Toxicology support and the Environmental Chemistry Laboratory. The scientists in both groups play an important role in ensuring that the crew of the ISS are breathing clean air and drinking clean water. Personnel within the TEC establish safe spacecraft environmental limits, monitor the air and water quality aboard current spacecraft (ISS and Commercial Crew and Cargo vehicles), and support technology advancements. The TEC employs in-flight monitoring capabilities as well as postflight sample analysis techniques to monitor the air and water quality from spaceflight.
An Agency Resource
The Toxicology group at JSC serves as the NASA-wide resource for aspects of space toxicology and is responsible for several different duties that are focused on protecting crewmembers and spacecraft systems from toxic exposures in spaceflight. These include assessing chemical hazards for flight, establishing limits for contaminants in spacecraft air and water, assessing and evaluating environmental data from spacecraft in flight, and assessing the potential for off-gas products from new vehicles or modules. These assessments are documented in:
The Environmental Chemistry laboratory at JSC occupies approximately 6,000 sq. ft. of laboratory space in one of the newest buildings on site. This is a fully equipped environmental and analytical laboratory with analysts that have supported multiple human spaceflight programs and provided center support for both gas and liquid analysis. The work in the laboratories operates under an ISO 9001/AS9100-certified quality plan with dedicated and independent quality personnel.
The Environmental Chemistry Laboratory monitors for contaminants in spacecraft air using both in-flight and post-flight methods. Onboard the International Space Station (ISS), 2 Air Quality Monitors (AQMs) use gas chromatography/differential mobility spectrometry to detect and quantify 23 target volatile organic compounds to provide near real-time insight into the status of the ISS atmosphere. Other real-time monitors supported by the Environmental Chemistry laboratory include the compound-specific analyzer-combustion products (CSA-CP), which use electrochemical sensors to analyze the atmosphere for the presence of compounds produced by fire, and the CO2 monitor, which uses non-dispersive infrared reflectance to monitor for the presence of elevated CO2. For detailed post-flight analysis in the Environmental Chemistry Laboratory, astronauts use grab sample containers to collect in-flight samples, which are then returned to JSC for a detailed environmental analysis. Similarly, formaldehyde monitoring kits contain badges used to collect formaldehyde. These also are returned to the ground for spectroscopic analysis.
The Environmental Chemistry Laboratory also analyzes archival samples returned from the ISS. The majority of water consumed by crewmembers on the ISS is recycled from a combination of condensed atmospheric humidity and urine. This wastewater is then treated by the U.S. water processor assembly (WPA) to produce potable water, which is analyzed to ensure that the water meets U.S. potability requirements. Samples of the humidity condensate and condensate/urine distillate also are returned for analysis to provide insight into the operation of the WPA and the overall US water recovery system. The TEC relies upon the in-flight analytical capability provided by the ISS total organic carbon analyzer (TOCA) to determine real-time total organic carbon concentrations, which are used to protect ISS crew health as well as manage the U.S. water system consumables. Similarly, the colorimetric water quality monitoring kit (CWQMK) is used to provide insight into the biocide concentration in the U.S. water.
Water samples are also collected in flight and stored for return to Johnson Space Center. The following ground-based equipment is used to analyze archival samples to ensure suitable air and water quality:
- Liquid Chromatography/Refractive Index Detection (LC/RI)
- Gas Chromatography/Flame Ionization Detector (GC/FID)
- Gas Chromatography/Thermal Conductivity Detector (GC/TCD)
- Trace Gas Analyzer
- Gas Chromatography/Mass Spectrometry (GC/MS)
- Liquid Chromatography/Mass Spectrometry (LC/MS)
- Inductively Coupled Plasma/Mass Spectrometry (ICP/MS)
- Ion Chromatography (IC)
- UV/VIS Spectrophotometry
- Fourier Transform Infrared Reflectance (FTIR)
- Total Organic Carbon Analyzer (TOCA)
In addition to analysis of flight samples and real-time data, the Environmental Chemistry laboratory team plays an important role in the development of new Environmental Control and Life Support Systems hardware by providing analytical support during ground testing. Similarly, the TEC scientists pursue and support technology demonstrations aimed at developing new methods for real-time data collection. Recent examples of this support have included the multi-gas monitor (MGM) and the personal CO2 monitor. TEC scientists make vital contributions to consolidating environmental monitoring hardware to reduce mass and volume requirements, both of which are important as NASA moves to more long-term missions in smaller vehicles.
Spaceflight Air and Water Quality
Toxicology and Environmental Chemistry (TEC) monitors airborne contaminants in both spacecraft air and water. In-flight monitors are employed to provide real-time insight into the environmental conditions on ISS. Archival samples are collected and returned to Earth for full characterization of ISS air and water.
Points of Contact
Paul Mudgett, PhD
Valerie Ryder, PhD DABT
Spencer Williams, PhD DABT
William T. Wallace, PhD