Coping with space environment: testing solid propellants for in-orbit use

TL;DR: Solid rocket motors are suitable for de-orbiting satellites at the end of their lifetime, as they can withstand harsh space conditions over an extensive period of time.

Abstract: The results of a risk reduction study are presented, proving the suitability of solid rocket motors (SRMs) to de-orbit satellites at the end of their lifetime. In a risk reduction program, three basic unexplored questions regarding this technological approach were investigated: (1) what are the effects of the size and type of particles ejected during the operation of SRMs; (2) what is the effect of the micrometeoroid impact on the solid propellant; and (3) what are the effects of prolonged exposure to space radiation during the 20-year expected satellite lifetime of satellites? Using a series of sophisticated and newly developed research approaches, it was shown that solid rocket propellants can withstand harsh space conditions over an extensive period of time. All of the tests were performed using a well-established, metal-free high-performance ammonium perchlorate/hydroxyl-terminated polybutadiene propellant fully qualified by military standards.