Page:Advanced Automation for Space Missions.djvu/78

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APPENDIX 3B

EXCERPT FROM HYPOTHETICAL TITAN MISSION LOG


1. Central Spacecraft Computer. a. Monitors progress of all operations. b. Initializes all tasks. c. Keeps log and communicates to Earth. d. Makes and tests hypotheses when anomalies from predefined "Planet Model" are found. 2. Spacecraft Imager. a. Records images in "snapshot" fashion (on retina-like array of detectors). b. Finds features asked for by central spacecraft computer. c. Notes anomalies in images from predefined "Planet Model." d. Is capable of describing images in terms of predetermined concepts. e. Updates "Planet Model" with new information based on image input. 3. Spacecraft Control Image Processor. a. Processes data scanned by visible, IR, microwave, and other image sensors. Puts data into "Planet Model." b. Performs tests asked for by Central Spacecraft Computer on this data. c. Identifies surface features and matches features to concepts stored in "Planet Model." d. Updates "Planet Model" based on new information. 4. Lander Central Image Processor. a. Main lander vision processor capable of looking in any direction. b. Performs scene analysis to locate objects of interest on surface and to locate position of lander. c. Retinal-type sensor input. d. Adds surface data to "Planet Model." 5. Lander Guidance Image Processor. a. Processes image data to determine safe path from present location to assigned destination. b. Updates "Planetary Model" contour map. c. Finds obstacles on ground during descent. 6. Central Lander Computer. a. Handles requests from central spacecraft computer. b. Plans lander actions based on these requests. c. Assigns tasks to Lander Central Image Processor and Lander Guidance Image Processor. HYPOTHETICAL SHIP'S LOG - SPACESHIP TITAN July 4,2010 REPORT: CENTRAL SPACECRAFT COMPUTER (CSCC) 9:00 am GMT Have Titan in view on spacecraft imager. Based on size of disk at 300 mm focal length, we are 504300 km from satellite. This agrees ?100 km with microwave (5680 GHz) ranging system. 9:10 am GMT - Zoomed to 3000 mm focal length. Approximately 5:30 am local zero meridian time. OBSERVATIONS SPACECRAFT IMAGER. 1. Satellite generally dark in appearance with some light blotches. Surface appears smoother than Earth's moon. 2. No polar caps observed. 3. Terminator sharp. 4. Limb at equator bright at surface. HYPOTHESIS: CSCC This indicates high-density model of atmosphere to be correct. QUERY: CSCC High-density atmosphere does not agree with sharp terminator observed. CSCC TO SPACECRAFT IMAGER: Task 1: When at range 20000 km, observe limb using spectral analysis procedure. Task 2: Measure spectral reflectance over 200 km X 500 km area centered on terminator at equator. OBSERVATIONS - SPACECRAFT IMAGER (cont.). 5. Several dark areas on surface near limb at 40? north latitude. Perpendicular projection would show these to be roughly circular. Areas very dark in center but lightens (like an inverse conic function) toward edges.