Advanced Automation for Space Missions/Appendix 3B

 

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. CSCC TO SPACECRAFT IMAGE PROCESSOR: Task 3: When in orbit, correlate contour map, spectral data, and geological analysis over this area to test for possible volcanic activity. July 10, 2010 REPORT: CSCC 1:30 pm GMT - Disk size at 300 mm focal length indicates range 20100 km from satellite. Agrees ?100 km with microwave ranging system. 1:35 pm GMT - Terminator observed through 560 nm, 630 nm, and 1080 nm spectral bands. Relative average reflectance 0.2, 1.5, 0.1, respectively, indicating dense atmosphere refraction properties. QUERY: CSCC ? Since dense atmosphere hypothesis was reinforced, why sharp terminator? CSCC TO SPACECRAFT IMAGER: Task 4: Cancel Task 1. Task 5: Measure geological activity in this area during orbit. July 20,2010 REPORT: CSCC 7:55 am GMT ? Orbit insert completed at 6:00 am. Beginning Titan resource survey for Planet Model. Visible, IR, and microwave scanners operating. Data being processed and stored. Contour map being generated. Gravity anomaly experiment initialized. 8:00 am GMT - OBSERVATION - SPACECRAFT IMAGER 1. White haze in image slightly obscuring surface. Cloudlike rather than bright surface. CSCC TO SPACECRAFT IMAGE PROCESSOR: Task 6: Check Planet Model stereo imagery to verify haze above surface. Response: Spacecraft Central Image Processor. 1. Verifies, white haze is above surface. Task 7: Check stored spectral data to estimate spectral characteristics of haze. Response: Spacecraft Central Image Processor. 1. Spectrum of samples areas matches methane. OBSERVATION - SPACECRAFT IMAGER 1. Presently over black blotches noted on Titan approach. CSCC TO SPACECRAFT CENTRAL IMAGE PROCESSOR: Task 8: Initiate Task 3 - Examine topography data over black areas. Response: Spacecraft Central Image Processor. 1. Contour map shows 3 circular black areas to be conic depressions 10 km, 5 km, and 6 km, respectively, in depth. 2. Spectral data indicates third IR band reflectance to be 1.6 times surrounding average in these areas. 3. Thermal IR indicates 100? ? at centers of cones decreasing to 50? ? at edges. HYPOTHESIS: CSCC ? Assume black areas to be craters. CSCC TO SPACECRAFT CENTRAL IMAGE PROCESSOR: Task 9: a. Analyze area surrounding black regions for height. b. Examine geological data for lineaments in surrounding area. Response: Spacecraft Central Image Processor. 1. In annuli(?, <r< l.l Rl;R2<R<\.2R2\ and R? < r < 1.15 R3) surrounding each black area {??, B2, and B3); depth decreases from inside edge to outside edge by 1 km, 0.5 km, and 2 km, respectively. 2. Radial lineaments exist inside annuli. None outside. COMMENT: CSCC - Crater hypothesis reinforced, since very warm in center, assume to be volcanic in origin. CSCC TO SPACECRAFT IMAGER AND CENTRAL IMAGE PROCESSOR: Task 10: Initiate Task 5 ? Analyze geological activity at terminator. Response: Spacecraft Imager. 1. Texture in grey levels along terminator indicate mountain size shadowing. Response: Spacecraft Central Image Processor. 1. Contour map indicates mountain range generally parallel to terminator from 70? south latitude. REPORT: CSCC - Present knowledge indicates mountains can cause sharp cutoff of light. Unless contradictory evidence, assume mountain range at terminator causes observed sharp cutoff of light at terminator.

July 31,2010 July 29,2010 REPORT: CSCC 8:25 am GMT - Initial Planet Model completed. Atmospheric sounder indicates planned descent to surface procedure possible. Beginning procedure for finding highest priority landing target. CSCC TO SPACECRAFT CENTRAL IMAGE PROCESSOR: Task 51: Correlate parameters for most desirable landing site with surface model. Response: Spacecraft Central Image Processor. 1. Highest priority areas ? Those indicating possible carbon-based life or structures made by intelligent beings. - None indicated by Planet Model. 2. Next highest priority - Areas indicating possible H2O. No indication of present H2O by surface model. Possible ancient riverbed 25?-27?N. latitude and 34?- 38? W. longitude. Topology map indicates possible target 25.1? N. latitude and 36.8? W. longitude. Target is within lander range of stratified river bank-like structures. July 30, 2010 REPORT: CSCC 9:45 pm GMT - Have loaded site model into Lander Central Image Processor. Task sequences programmed to deploy parachute at 100 km, begin wind determination and parachute descent path modification at 45 km. Parachute to be ejected at 2 km. Landing rockets and obstacle avoidance imaging system to be initiated at 1500 m. 10:31 pm GMT - Initiating Lander Descent. Response: Lander Central Image Processor. 1. Have locked onto target area. 2. Estimated ground drift and surface wind indicates parachute descent direction modification of 265? and 3.1 km necessary to hit target. 3. Obstacle avoidance system activated. Response: Lander Guidance Image Processor. 1. Obstacle at site. Shift 30?, 0.16 km. 2. Site clean under lander, okay for vertical descent to surface. REPORT: CENTRAL LANDER COMPUTER (CLC) 1:38 am GMT - Lander site assessment procedure initiated. Lander Guidance Imaging System turned on. Response: Lander Central Image Processor. 1. Surface immediately surrounding lander mostly small rocks on relatively flat surface. Hill (slope < 30?) blocking view beginning 100 m away 248? to 0?. Surface of hill easily navigable. Stratified rock wall beyond 1 km 0? to 20?. Hill obscures wall beyond 0?. CLC TO LANDER GUIDANCE IMAGE PROCESSOR. Task 1: Initiate analysis to find safe path to climb to apex. Response: Lander Guidance Image Processor. 1. Stereo depth and contour data added to site model. 2. Safe path calculated. 3. Initiating journey. 4. Apex of hill reached. Stereo depth and contour data being added to site model. 5. Safe path possible in forward direction. OBSERVATION LANDER CENTRAL IMAGE PROCESSOR.

Rock formation indicating upheaval at 240?.

No major obstacles indicated on Planet Model.

No major obstacles indicated in image pointed at 240? CLC TO LANDER GUIDANCE IMAGE PROCESSOR. Task 2: Initiate analysis to find safe path to formation. Response: Lander Guidance Image Processor. 1. Safe path calculated for initial 100 m. 2. Beginning journey. 3. Dead reckoning from surface model and relative size indicates 0.5 of total distance covered. 4. Dead reckoning and size of upheaval in image indicates 300 m from upheaval. 5. Slowing down. 6. At base of upheaval. Rubble makes further progress in this path impossible.

CLC TO LANDER GUIDANCE IMAGE PROCESSOR. Task 3: Initiate experiment No. 4379 - Rock specific density. Response: Lander Guidance Image Processor. 1. Reconfiguring to manipulator vision configuration. 2. Located oval shaped rock 3 cm X 8 cm, not imbedded, within reach of manipulators. 3. Surface model for 0.5 of rock recorded. 4. Initiating manipulator to lift and weigh rock. 5. Rock weighs 15 N, Mass = 10 kg. 6. Initiating rotation of rock 180? with respect to initial position. 7. Surface model for remaining 0.5 of rock recorded. 8. Volume of rock is 0.010 m3. Density is 1000 kg/m3.