Title :
Method to employ covariate data in risk assessments
Author_Institution :
Attwater Consulting, Webster, TX, USA
Abstract :
The International Space Station Program experienced a problem with the extra vehicular activity (EVA) pre-breathe oxygen (O2) sensor on-board the International Space Station (ISS). Astronauts on the ISS must pre-breathe a mixture rich in oxygen prior to a scheduled EVA to prevent nitrogen narcosis (the bends) during the EVA. The O2 measurement from this sensor on the pre-breathing apparatus was observed during its 270 day mission to be in error by more than ±6mmHg, subjecting the life of the EVA astronaut to an unacceptable risk. The ISS Program was faced with either halting EVA´s for the ISS until this sensor could be redesigned, tested, and delivered to the ISS, or finding some other way to reduce this risk to the EVA astronauts to an acceptable level.
Keywords :
aerospace instrumentation; covariance analysis; gas sensors; risk management; space research; space vehicles; covariate data; extra vehicular activity; international space station program; on-board; pre-breathe oxygen sensor; risk assessments; Calibration; Data models; Equations; Joints; Mathematical model; Measurement errors; Uncertainty;
Conference_Titel :
Aerospace Conference, 2011 IEEE
Conference_Location :
Big Sky, MT
Print_ISBN :
978-1-4244-7350-2
DOI :
10.1109/AERO.2011.5747630
