Suggested Citation:
D'Souza, Sarah, Nesrin Sarigul-Klijn, Christopher Cerimele (2008) Development and Simulation of an Analytic Skip Earth Re-Entry Guidance Algorithm. AIAA Space 2008 Conference and Exposition

An Analytical Skip Entry Guidance (ASEG) algorithm is developed and simulated for a low L/D spacecraft. Formulation is based on an adaptation of the analytical theory developed for the Shuttle Entry Guidance (SEG). The validation study showed that, the SEG assumption of the flight path angle to be zero is not applicable. More accurate reference altitude rate profile and range prediction were developed when the flight path angle was assumed to be nonzero. In addition, the scale height formulation was modified for the first segment of the 1st entry phase in order to complete the development of a valid reference altitude rate profile. Given these modifications, a baseline ASEG algorithm was integrated with the Simulation of Rocket Trajectories Program and full simulations were completed. The baseline simulation revealed that the ASEG reference L/D developed for segment 1, did not provide a correct bank command profile to achieve a skip trajectory. Thus, a constant L/D was implemented for the first segment of the 1st entry phase and the baseline simulation was established, range targeting technique was implemented in the ASEG algorithm and flight simulations were completed using SORT. The ASEG algorithm and range targeting are applied after entry interface when the drag acceleration is approximately 0.2g’s and terminates targeting as the vehicle approaches 0.2g’s towards exit. The results show that the ranging technique commanded the vehicle to fly a total range that was within 3.2% of the nominal projected total range.