An enhanced shutter to protect spacecraft windows from meteoroids and orbital debris

Conventional spacecraft window shutters are relatively thin aluminum covers (0.1cm to 0.2cm thick), which provide only modest protection from meteoroid/orbital debris (M/OD) impacts. This paper provides results of an intensive effort to develop an improved shutter design capable of protecting fused-silica glass windows from 1.3cm diameter aluminum projectiles impacting at 7 km/s. Hypervelocity impact tests on a number of shutter concepts under a variety of impact conditions are described. Ballistic limit equations are defined that allow assessment of impact damage to shutter protected spacecraft windows. An immediate application for the enhanced shutter design is to provide robust meteoroid/debris protection for windows of the International Space Station (ISS) Cupola. Enhanced shutter designs provided here would be applicable to protecting other spacecraft windows and sensitive surfaces, whenever high levels of reliability and M/OD protection are desired. (C) 2003 Published by Elsevier Ltd.