Title :
Risks of particle hits during space walks in low Earth orbit
Author :
PatÉ-cornell, Elisabeth ; Sachon, Marc
Author_Institution :
Dept. of Manage. Sci. & Eng., Stanford Univ., CA, USA
fDate :
1/1/2001 12:00:00 AM
Abstract :
The construction of the International Space Station (ISS) may involve several thousand hours of space walks or “extravehicular activities” (EVAs). Among the many risks involved in EVAs, we focus here on potential failures of the external maneuvering unit (EMU) caused by impacts of space particles (micro-meteoroids and orbital debris). We present a probabilistic risk analysis (PRA) model based on available data for the particle flux in low Earth orbit as well as test data obtained at Johnson Space Center about the capacity of the current EMU to absorb these loads. We computed the risk for a peak year of EVA activity, assumed by NASA to consist of 624 hours of EVA exposure. For that time period, we found that, the probability of a fatality is about 1.4*10-3 without shielding and 1.1*10-3 per 624 hours of EVA with shielding, This model can be used as support for a number of decisions regarding space suit design, astronaut shielding options, and overall number of EVA hours for space station construction and operation
Keywords :
aerospace biophysics; aerospace simulation; meteoroids; probability; risk management; safety; shielding; space debris; space vehicles; International Space Station; astronaut shielding options; external maneuvering unit; extravehicular activities; fatality probability; low Earth orbit; micrometeoroids; orbital debris; particle hit risks; probabilistic risk analysis model; space particles; space station construction; space walks; spacesuit design; Fires; Industrial accidents; International Space Station; Low earth orbit satellites; NASA; Risk analysis; Space debris; Space exploration; Space stations; Testing;
Journal_Title :
Aerospace and Electronic Systems, IEEE Transactions on
