Performances of Kevlar and Polyethylene as radiation shielding on-board the International Space Station in high latitude radiation environment

Livio Narici,Veronica Zaconte,Alessandro Rizzo,Marianna Larosa,Luca Di Fino,Marco Casolino,Piergiorgio Picozza

doi:10.1038/s41598-017-01707-2

Livio Narici, Veronica Zaconte + Show 5 more

Open Access

https://doi.org/10.1038/s41598-017-01707-2

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Journal: Scientific Reports	Publication Date: May 10, 2017
Citations: 41	License type: open-access

Affiliation: University of Rome Tor Vergata

Abstract

Passive radiation shielding is a mandatory element in the design of an integrated solution to mitigate the effects of radiation during long deep space voyages for human exploration. Understanding and exploiting the characteristics of materials suitable for radiation shielding in space flights is, therefore, of primary importance. We present here the results of the first space-test on Kevlar and Polyethylene radiation shielding capabilities including direct measurements of the background baseline (no shield). Measurements are performed on-board of the International Space Station (Columbus modulus) during the ALTEA-shield ESA sponsored program. For the first time the shielding capability of such materials has been tested in a radiation environment similar to the deep-space one, thanks to the feature of the ALTEA system, which allows to select only high latitude orbital tracts of the International Space Station. Polyethylene is widely used for radiation shielding in space and therefore it is an excellent benchmark material to be used in comparative investigations. In this work we show that Kevlar has radiation shielding performances comparable to the Polyethylene ones, reaching a dose rate reduction of 32 ± 2% and a dose equivalent rate reduction of 55 ± 4% (for a shield of 10 g/cm2).

Highlights

The goal of such studies is to reduce the radiation risk for the crew to a level As Low As Reasonably Achievable (ALARA), down to the ideal case where the risk for radiation exposure in space is comparable to the one on Earth, not to affect the allowable mission duration
In this paper we show the results of the measurements performed in the International Space Station (ISS) during the ALTEA-shield project for the investigation of the shielding effectiveness of Polyethylene and Kevlar
The ALTEA detector system is composed by six identical Silicon Detector Units (SDUs) and a Data Acquisition Unit (DAU)

Summary

Introduction

The goal of such studies is to reduce the radiation risk for the crew to a level As Low As Reasonably Achievable (ALARA), down to the ideal case where the risk for radiation exposure in space is comparable to the one on Earth, not to affect the allowable mission duration. Measurements in Low Earth Orbit (LEO) at high latitude allow the investigation of a radiation field similar to the deep-space one, with the correct ions spectrum, needed to evaluate the material characteristics as radiation shield. These measurements are much more resource demanding than the ground based ones. Even if within the protection of the Earth’s magnetic field, the spectrum of the radiation environment inside the ISS at high latitudes is the closest available replica of the outer space radiation spectrum[2]

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