Demanding tribological properties are required of the materials used for the sliding seal between the sidewalls and the lower wall of the advanced hypersonic engine. Temperatures range from room temperature and below to operating temperatures of 1000°C in an environment of air, hydrogen and water vapor. A candidate sealing material for this application is an alumina-boria-silicate, ceramic, fabric rope sliding against the engine walls which may be made from copper or nickel based alloys. Using a pin-on-disk tribometer, the friction and wear properties of some of these potential materials and possible lubrication methods are evaluated. The ceramic fabric rope displayed unacceptably high friction coefficients (0.6 to 1.3) and, thus, requires lubrication. Sputtered thin films of gold, silver and calcium fluoride reduced the friction by a factor of two. Sprayed coatings of boron nitride did not effectively lubricate the fabric. Static heat treatment tests at 950°C indicate that the fabric may be chemically attacked by large quantities of silver, calcium fluoride and boron nitride. Sputtered films or powder impregnation of the fabric with gold may provide adequate lubrication up to 900—1000°C without showing any chemical attack.Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in Baltimore, Maryland, October 16–19, 1988