Test panels covered with an advanced foam insulation material for the Space Shuttle's giant external fuel tank were test flown aboard an F-15B research aircraft at NASA's Dryden Flight Research Center, Edwards, Calif. Six panels were mounted on the left side of a heavily instrumented Flight Text Fixture mounted underneath the F-15B's fuselage. Insulation on this panel was finely machined over a horizontal rib structure to simulate in-line airflow past the tank; other panels had the ribs mounted vertically or had the insulation left in a rough as-sprayed surface. The tests were part of an effort by NASA's Marshall Space Flight Center to determine why small particles of the new insulation flaked off the tank on recent Shuttle missions. The tests with Dryden's F-15B were designed to replicate the pressure environment the Shuttle encounters during the first minute after launch. No noticeable erosion of the insulation material was noted after the flight experiment at Dryden.