Aerogel for Aerospace Applications

Abstract

Aerogels are the lightest insulation materials known today with a thermal conductivity in the range of 0.001- 0.03 W/K. The first patent concerning silica aerogel dates back to the 1932, but the first aerospace application was realized many years after, in 2003, when aerogels were selected as thermal insulation to realize the box containing the lithium batteries for the rover in the NASA Mars mission. Afterwards, silica aerogel was successfully used in the Stardust spacecraft to trap cosmic particles from the comet tail. Next challenge is making silica suitable for structures. In fact, the real limitation of using aerogel for advanced aerospace applications is in their mechanical properties and manufacturing, that are not so exceptional as the thermal ones. For this reason, a great number of current studies on silica aerogel is concerned with the improvement of the mechanical properties. This paper is a review on recent developments of aerogels and their properties for current and future application in aerospace field. Keywords: Aerogel, thermal insulation, thermal conductivity mechanical properties, meso-porous structures, fiber-reinforced silica aerogel composite, low density, optical properties, gel process, polymeric-reinforced silica aerogel, space missions, space applications, extra-vehicular activity, Martian base, flexible blankets