Energy reference guidance for drag-modulated aerocapture.

• A novel guidance algorithm for drag-modulated aerocapture is presented. • The algorithm is compared in detail to an efficient implementation of the state of the art solution, a numerical predictor-corrector, and is shown to achieve equivalent targeting performance for significantly lower computational expense. • This contribution could thus meaningfully advance the near-term technical feasibility of drag-modulated aerocapture. Aerocapture is a method of achieving orbit insertion via a single pass through the atmosphere of the central body. Single-event jettison drag modulation is a simple way of achieving control during atmospheric flight by effecting a discrete change in the aerodynamics of the vehicle. A novel guidance algorithm, energy reference guidance, is developed and implemented for a reference scenario of a small satellite aerocapture demonstration at Earth, and is compared to the baseline numerical predictor–corrector solution. The new approach is shown to achieve equivalent apoapsis targeting performance as the baseline algorithm with significantly lower CPU demand during atmospheric flight, although more onboard memory is required in exchange. The relationship between targeting performance and required memory is quantitatively explored for the new algorithm; the selected configuration generates approximately 3.3 MB of data, which is expected to be well within the capability of relevant avionics systems. [ABSTRACT FROM AUTHOR]