Test results for entry guidance methods for space vehicles

There are a number of approaches to advanced guidance and control that have the potential for achieving the goals of significantly increasing reusable launch vehicle (or any space vehicle that enters an atmosphere) safety and reliability and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies has recently completed a rigorous testing phase, where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. The primary contribution of the paper is to provide a quantitative comparison between the performance of five different entry guidance approaches. Results show a significant improvement over the current state of the art (shuttle-like guidance). The two best-scoring algorithm approaches show roughly equivalent results. Both can be expected to work well for future vehicle concepts.