Abstract: A system and method to enhance attitude estimation for transfer orbit maneuvers of a spinning satellite includes a transfer orbit earth sensor that can receive and convert an infrared radiance to an analog signal. The analog signal is provided to a hardware chord processor and an analog-to-digital converter. The hardware chord processor determines an earth chord length based on the analog signal. The analog signal is sampled in the analog-to-digital converter to provide a digital signal to a digital earth sensor pre-processor, which reshapes the digital signal to provide a pre-processed signal having nearly distinct peaks. A software chord processor is provided with the pre-processed signal. The software chord processor locates the peaks in the pre-processed signal and determines an earth chord length.

Abstract: A method for acquiring a target from a vehicle including a sensor mounted thereon having a field of view centered on boresight. The method includes rotating the sensor about a first fixed axis, rotating the sensor about a second fixed axis generally perpendicular to the first axis as the sensor is rotated about the first axis, moving the sensor so the boresight is aligned with the target, and stopping movement of the sensor when the boresight is aligned with the target.

Abstract: A method for modeling a structure deployed on a spacecraft. The method includes determining a geometric shape that resembles the structure in a fully deployed configuration; generating time functions for a change in shape of at least one structural component of the structure, the change in shape occurring as the structure expands into the fully deployed configuration; and calculating mass properties of the geometric shape as a function of the time functions.