In engineering systems with extreme environmental conditions, proper sealing of machine components is especially important, e.g. in the space industry. The effectiveness of the seal depends largely on the method of sealing and the materials used. The investigation aims to research the abrasion phenomena of moving machine elements of the rotary shaft/seal relationship that is subjected to dry friction and intense abrasion in Martian and Lunar environments. The main objective is to determine the wear sensitivity of the rotating shaft/sealing units by performing laboratory tests both on a simplified coupon level and in a more complex real shaft/seal connection test. These enable material ranking and aid further material selection for the application.