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Systems engineering at detector level. Tim Stevenson. Elements. Requirements engineering Accommodation engineering Optical Mechanical Thermal Electrical Quality engineering Verification Reliability – Risk Mitigation Serviceability Documentation Model Philosophy.
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Systems engineering at detector level Tim Stevenson
Elements • Requirements engineering • Accommodation engineering • Optical • Mechanical • Thermal • Electrical • Quality engineering • Verification • Reliability – Risk Mitigation • Serviceability • Documentation • Model Philosophy
Requirements Engineering • Science Requirements leading to: • Observatory requirements (pointing, stability, etc) • Chosen detector technology + implementation • Position and Envelope • Mass • Alignment precision • Electrical • Power • Noise environment • FE electronics • I/F to separate electronics • Thermal • Stray light • Contamination control • Mechanisms • Mission requirements • Schedule • Budget allocations • Envelope • Environment • Thermal • Mechanical • Radiation • Electrical • Attitude disturbance • Reliability • Redundancy • Life • AIV approach • Test and verification facilities • Storage, transportation
Accommodation • Optical requirements and Optical packaging • Position and Volume • Vacuum vessel & door/window • Alignment approach • Protection – Door, purging • Mechanisms • Stray light control • FP technology specifics • Sealed tube? • Thermal requirements • Radiator size, proximity and attitude wrt Sun & Earth • Dissipation, detector and FEE • Isolation, detector and FEE • Electrical requirements • HT discharge precautions, power efficiency • Proximity of FEE • Relation to main electronics • Radiation protection
Quality Engineering • Requirements & Design for verification • Testable at all stages • Calibratable and stable • Build quality • Traceable materials and parts of known quality • Tried and tested processes • Requirements & Design for reliability/confidence • Lessons Learnt from previous similar instruments • Redundancy where possible • Failure mode, effect and criticality analysis • Cleanliness • Self test, internal calibration, housekeeping parameters, raw data availability • Requirements & Design for serviceability • Spare parts • Access
Documentation • Hierarchy of requirements • Specifications • Interface Control Documents • Plans • Procedures • Assembly • Test • Operations • Reports
Detector Model Philosophy • Deliverable models • Whatever WSO/Lavotchkin requires, STM, EM & FM • Perhaps consider full FS focal plane • Development models (dev. function) • Working backwards: • Flight Model (calibration) – tested to acceptance levels • Ground engineering model (calibration, stability, troubleshooting, software development) • aka Validation Model, qualification levels in test • Breadboard model (manufacture & assembly development) • Qualification could be done on FM (Proto-flight philosophy – overdesign)