Miguel A. Aguirre. Introduction to Space. Systems. Design and Synthesis. ) Springer

Transcription

1 Miguel A. Aguirre Introduction to Space Systems Design and Synthesis ) Springer

2 Contents Foreword Acknowledgments v vii 1 Introduction Aim of the book Roles in the architecture definition process The perspective during the system architecture definition phases Design and implementation as a evolving process Proj ect phases and proj ect reviews What is a space system? Terminology Recommended supplementary reading 16 2 Space Disciplines Space system engineering Integration and control Interfaces management Requirements engineering System analysis Design and configuration definition Verification Space system architecting The architect in the classical role Architecture definition formalisms Project management Satellite engineering disciplines Structure Thermal control Mechanisms Attitude control Propulsion Electrical power Data handling Software Communications Instruments engineering Engineering support disciplines Manufacturing assembly, integration, verification, and testing engineering Product assurance 40 ix

3 X Introduction to Space Systems Satellite flight operations Satellite data output processing Cost engineering The consumer: the scientist behind the mission 43 3 Requirements, Specifications, and Design Levels of system decomposition Specification and requirements types Specification types Requirements types Requirements for technical specifications Requirements engineering Value engineering The different values of requirements System effectiveness metrics Requirements and verifiability 62 4 Constraints and Design Requirements versus constraints The external environment of a space project STEP analysis Forecasting and scenario analysis History of selected past space endeavors Private versus public communications and Earth observation Apollo The programmatic framework as constraint Types of projects by project aims Capabilities demonstration Technical demonstration Advancement of science Operational Type of projects by projects criticality Types of projects by project size Cost Top-down cost estimation Bottom-up cost estimation The risk of cost estimations Single satellite versus multiple satellites cost Risk constraints Qualitative risk management Quantitative risk management Technical readiness and technical development Developmental approach and model philosophy Schedule constraints Management trends as constraints 92

4 Contents xl 5 System Design as a Synchronic Process Space system elements System specification, system design, and system architect Design against constraints Cost Risk Schedule Design against requirements Tools for design Analysis and design Functional analysis and functional decomposition Trade-offs and design Budget allocation engineering Concurrent engineering Dependability Design and mission performances Mission effectiveness metrics Effectiveness metrics limitations Safety margins, mistakes, and errors Nonnumerical support to decision making Numerical support to decision making Deterministic approaches Nonprobabilistic numerical approaches in situation of uncertainty Probabilistic approaches System Definition as a Diachronic Process The system definition process as recurrent and linear System definition as a recursive process System definition as a linear process Phase Phase A Phase Bl Mission milestones and reviews Review procedure Reviews during the mission definition stages Parallel developments Technical maturity improvement Scientific understanding advancement Introduction to the Design Domains Design interactions and design domains The observables and instruments domain The orbit and attitude domain The satellite configuration domain The satellite operations data flow domain The instrument output data flow domain 156

5 Introduction to Space Systems 7.2. The astronomical observatory missions as an example of space system design Mission descriptions Comparison ofthe missions Observatory mission highest-level design interactions Multi-satellite design aspects Data quantity and quality versus number of satellites Mission life versus number of satellites Systems of systems 175 The Observables and Instruments Domain Observables and instrument selection Elements and components involved in the observables and instruments domain Passive optical Active optical Passive microwave Active microwave In situ instruments Communication payloads Instruments examples Aeolus JWST Sentinel Megha-Tropiques Ulysses Observational needs as design drivers Observation frequency and atmosphere Data quality Image distortion Data quantity Systematic versus interactive observation Responsiveness, acquisition delay, and latency Observations and rotation of the line of sight Instrument interfaces End-to-end performance as design driver Allocation of functions Scanning Internal and external calibration Solid aperture versus deployable versus synthetic aperture Resolution versus altitude Allocation of budgets Radiometric quality MTF The end-to-end performance 224

6 Contents xiii 9 The Orbit and Attitude Domain Elements and components involved in the domain Launchers Orbit determination and correction Attitude determination and control The space environment as orbit and attitude design driver Gravity field Earth's magnetic field Neutral atmosphere Solar radiation Ionosphere radiation The space environment outside the Earth Attitude and attitude types Uncontrolled satellite attitude Gravity-gradient attitude control Stabilized by rotation attitude control Dual spin and momentum bias attitude control Inertially stabilized attitude control Orbits and orbit types Low Earth Orbit (LEO) LEO Sun-synchronous orbit MEO Geosynchronous and geostationary orbits Longer period Earth orbit Lagrangian points Interplanetary orbits Orbits around other planets Mission phases and modes and satellite attitude Orbit and attitude examples Sentinel Ulysses Iridium Pleiades Geometry around the satellite Nadir pointing Rotating satellites Inertial satellites Pointing control, pointing perturbations, and pointing corrections Satellite and instruments pointing and pointing perturbations Pointing control, pointing perturbing torques, image acquisition, and frequency ranges Pointing error types Allocation offunctions Orbit selection Attitude selection Coverage and revisit 293

7 tjv Introduction to Space System Allocation of budgets Satellite location Instruments line of sight pointing and recovery Pointing stability realization and recovery Geo-locating Co-registration Repointing agility requirements Delta V and fuel Mechanical perturbations Implementation and maintenance of constellations The Satellite Configuration Domain Components involved in the domain Structure Thermal Mechanisms Solar array The external environment as configuration driver Launcher Load environment Thermal radiation environment: Sun, Earth and deep space Space environment generated external forces and torques Electromagnetic radiation environment Other effects of the external environment Configuration examples GOCE Ulysses JWST Iridium The geometry around the satellite and the configuration Nadir-pointed satellites Spinning satellites Inertially pointed satellites Agile satellites Allocation of functions Primary structural shape Deployable structure and mechanisms: Fixed versus deployable Standard platform versus dedicated platform Passive versus active thermal control Pointing by the instrument versus pointing by the satellite Allocation of performances Mass budget Heat budget 369

8 Contents xv Power production budget Alignment budgets Volume budget The Operational Data Flow Domain In-orbit components involved in the domain Power Satellite data handling Telemetry and telecommand data communications On-ground components involved in the domain Operational ground stations and data-relay satellites 381 U.2.2. Mission operations control centers Mission phases Launch and early operations Commissioning ofthe satellite Nominal operation Safe mode and other dormant modes Nominal orbit correction maneuvers Decommissioning and disposal Examples of data handling architectures Cluster Rosetta Sentinel SSTL-DMC Allocation of functions Systematic versus interactive operations Autonomy versus ground intervention Fast versus slow commanding Number and location of operational ground station Orbit determination and control functions allocation Allocation of performances Power budget Communications link budgets Computer load budget 412 U.6.4. Operational on-board storage Data acquisition delay budget Level of service and availability budget The Instrument Output Data Flow Domain In-orbit components involved in the domain Instrument output data handling Instrument data output downlink On-ground components involved in the domain Instrument downlink ground stations and data relay satellites Payload data segment 420

9 [Vj Introduction to Space Systems Examples of architectures Cluster Rosetta Sentinel NOAA-POESS Allocation of functions Large versus small amount of data Short versus long data latency Existing, to-be-acquired and subscribed products In-orbit versus on-ground processing Number and location of ground stations Centralized versus decentralized processing Science operations separated or as part of overall operations Allocation of performances On-board storage memory budget Data downlink budget Data latency budget Space Missions Cost and Alternative Design Approaches The space mission and cost Methods of cost reduction Proper architectural definition Hardware optimization Organization optimization Organization and hardware centered: small simple satellites within a lean project organization Projects without the duality sponsor/consumer Projects with a very low level of novelty, projects without customer Cost engineering as art and science 462 Index 465