Higher-order methods such as state transition tensors (STTs) have shown promise for a variety of applications in astrodynamics, but can be limited in their use due to their potentially large computational and storage requirements. In this paper we present a method for approximating STTs by aligning the STTs with particularly unstable directions. This strategy allows us to isolate the most important terms in the higher-order STTs and ignore any less important terms. This method, which we call directional state transition tensors (DSTTs), is applied to several examples in two- and three-body dynamic systems, and it is shown to perform well for both nonlinear state and state uncertainty propagation. The method produces similar results to the full STTs, but requires significantly fewer elements to be stored, which can result in up to [Formula: see text] improvements in speed for nonlinear uncertainty propagation computations. DSTTs are promising for expanding the use of STTs to situations with highly nonlinear dynamics but limited computational resources, such as on-board a spacecraft.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.