Predicting Air Quality at First Ingress into Vehicles Visiting the International Space Station
| Autor: | Jennifer J Hand, Thomas Limero, Patti Cheng, Robert R. Scully, John T. James, Vanessa de Vera, Amelia A Romoser, Valerie E. Ryder |
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| Rok vydání: | 2017 |
| Předmět: |
Engineering
Chromatography Gas Meteorology United States National Aeronautics and Space Administration Air pollution Crew medicine.disease_cause 01 natural sciences Gas Chromatography-Mass Spectrometry 010305 fluids & plasmas 010309 optics 0103 physical sciences International Space Station medicine Humans Spacecraft Air quality index Simulation Pollutant Aldehydes Ethanol Payload business.industry Air General Medicine Space Flight Butanones United States Air Pollution Indoor Aerospace Medicine Linear Models Sample collection Gases business |
| Zdroj: | Aerospace medicine and human performance. 88(2) |
| ISSN: | 2375-6314 |
| Popis: | Introduction NASA regularly performs ground-based offgas tests (OGTs), which allow prediction of accumulated volatile pollutant concentrations at first entry on orbit, on whole modules and vehicles scheduled to connect to the International Space Station (ISS). These data guide crew safety operations and allow for estimation of ISS air revitalization systems impact from additional pollutant load. Since volatiles released from vehicle, module, and payload materials can affect crew health and performance, prediction of first ingress air quality is important. Methods To assess whether toxicological risk is typically over or underpredicted, OGT and first ingress samples from 10 vehicles and modules were compared. Samples were analyzed by gas chromatography and gas chromatography-mass spectrometry. The rate of pollutant accumulation was extrapolated over time. Ratios of analytical values and Spacecraft Maximum Allowable Concentrations were used to predict total toxicity values (T-values) at first entry. Results were also compared by compound. Results Frequently overpredicted was 2-butanone (9/10), whereas propanal (6/10) and ethanol (8/10) were typically underpredicted, but T-values were not substantially affected. Ingress sample collection delay (estimated by octafluoropropane introduced from ISS atmosphere) and T-value prediction accuracy correlated well (R2 = 0.9008), highlighting the importance of immediate air sample collection and accounting for ISS air dilution. Discussion Importantly, T-value predictions were conservative 70% of the time. Results also suggest that T-values can be normalized to octafluoropropane levels to adjust for ISS air dilution at first ingress. Finally, OGT and ingress sampling has allowed small leaks in vehicle fluid systems to be recognized and addressed.Romoser AA, Scully RR, Limero TF, De Vera V, Cheng PF, Hand JJ, James JT, Ryder VE. Predicting air quality at first ingress into vehicles visiting the International Space Station. Aerosp Med Hum Perform. 2017; 88(2):104-113. |
| Databáze: | OpenAIRE |
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