Arcjet Testings of Silica Aerogel Toward Mars Aeroflyby Sample Collection Mission

Abstract

†† Heating tests of silica aerogel are carried out in an arcjet wind tunnel facility in order to examine whether it is suitable for the sample collector material used in the Mars Aeroflyby Sample Collection mission. After the heating tests, the surface of the aerogel test piece is visually inspected by using a digital microscope. Considerabel alterations are observed on the aerogel surface. The surface of aerogel has become black, and many crevices have developed along the aerogel surface. In addition, the surface seems to become hard due to a glassy material. In order to confirm that such damaged aerogel plays a role of the sample collector, preliminary simulation experiments are performed by using the two-stage light gas gun. In the experiments, 30µm-diameter spheres imitating the Martial dust particles are launched against aerogel target at the velocity of about 4.2km/s. A carrot-shaped tracks carved by the launched spheres are compared between the aerogel test pieces before and after heating test. It is found that the particle could be captured by the damaged aerogel without mechanical destruction if the particle has a diameter of the order of 10µm.