Ablation Performance Characterization of Thermal Protection Materials Using a Mach 4.4 Sled Test

Sled tests are often used to evaluate ablation performance and to provide design parameters for predicting thermal protection requirements for missile structures. This paper presents a discussion of such a test, performed to determine values of heats of ablation versus ablation temperatures for six materials which are candidates for use i n external thermal protection schemes. These relations can then be used to predict ablation performance of these materials when being subjected to aero-heating environments having heating regimes which are reasonably similar to those of the test. When subjected to aerodynamic heating during high speed flight. missiles require exterior thermal protection to maintain structural integrity of the load carrying structures. Constraints, such as ease of application; low-cost, well defined thermal properties; low-weight; and good ablative/insulative performance are normally placed on the thermal protection. A test program was developed to identify. test. and evaluate the performance of several materials for use as ablative /insulative thermal protection layers (TPL) for high-velocity, low-altitude missile systems. A sled test was performed at the Hypervelocity Sled Track Facility at Holloman Air Force Base, New Mexico in which the selected materials were evaluated.