Analysis of Slewing and Attitude Determination Requirements for CTEX

This thesis examines the slewing and attitude determination requirements for the Chromotomographic Experiment(CTEX), a chromotomographic-based hyperspectral imager, to be mounted on-board the Japanese Experiment Module (JEM) External Facility (EF). The in-track slewing requirement is driven by the facts that CTEx has a very small field of view (FOV) and is required to collect 10 seconds of data for any given collection window. The need to slew in the cross-track direction is a product of the small FOV and target/calibration site access. CTEx incorporates a two-axis slow-steering dwell mirror with a range of +/- 8 degrees and an accuracy of 10 arcseconds in each axis to slew the FOV. The inherent inaccuracy in the knowledge of the International Space Station's (ISS)attitude (+/- 3 degrees) poses significant complications in accurately pointing CTEx even with more accurate (0.3 degrees) attitude information provided by the JEM. The desire is for CTEx to incorporate a star tracker with 1 arcsecond accuracy to determine attitude without reliance on outside sources.