The purpose for the first test series was simply to learn what projectile sizes would penetrate completely through the TUFI tile and the honeycomb backing, or cause spall from the rear of the honeycomb. For the AFRSI blankets, the failure criterion also required the impact to pentrate or cause detached spall from an aluminum sheet rear wall mounted 10 cm (4") behind the honeycomb. These failure criteria, for TUFI and AFRSI, would endanger crew members of an actual X-38 attempting to enter Earth's atmosphere.

The tests indicated that the minimum projectile size to cause failure was between 5.56 mm (7/32") and 6.35 mm (1/4") for TUFI tile targets. For AFRSI targets, the projectile size for failure was slightly larger than 6.35 mm (1/4").