Introduction to Space Technology - SN 209 Lecture 1

Introduction to Space Technology

• Course: SN 209
• Instructor: Dr. Mohamed Elfarran
• Lecture 1: Introduction

What is a Space System?

• Ground Segment:
  • Spaceflight Operations
  • Payload Operations (can be separate)
  • Payload Data Processing (e.g., Hubble)
• Space Segment:
  • Spacecraft
  • Supporting Craft (e.g., TDRSS, Progress)
• Launch Segment:
  • Launch Vehicle Integration
  • Launch Operations

Tracking and Data Relay Satellite System (TDRSS)

• A satellite system for tracking and data relay
• Multiple frequencies for communication
• Used to communicate with various spacecraft (e.g., Shuttle, KSA User, Hubble)

What Does a Spacecraft "Look" Like?

• Spacecraft "appearance" is often functional over form
• Physical constraints: Launch Vehicle, Payload Fairing, Power Loads, Vehicle Dynamics, Mission Trajectory, Pointing
• Examples of spacecraft components: Communications Antenna, Primary Mirror, Secondary Mirror, Telescope Pointing System, Solar Array, Aperture Door, Light Shield

Spacecraft Description

• Main Parts:
  • Mission Payload: Subsystem for the actual mission (communications, remote sensing, etc.) Including hardware and software for data handling and telemetry/command. Can include secondary payloads.
  • Spacecraft Bus: Hardware and software to support the mission payload, providing power, temperature control, structural support and guidance/navigation.

TDRSS 1-7 Specifications

• Dimensions: 45 feet wide/57 feet long
• Weight: 5000 pounds
• Design Lifetime: 10 years
• Power (EOL): 1800 watts
• Services: KU & S-Band services
• Launch Vehicle: Space Shuttle
• Orbit: Geosynchronous

Spacecraft Bus Subsystems

• Electronic Power System (EPS)
• Position and Attitude Control:
  • Attitude Control System (ACS)
  • Guidance, Navigation, and Control (GNC)
  • Propulsion ("Prop")
• Command and Data Handling (C&DH):
  • Data Handling (Mission Data)
  • Telemetry, Tracking, and Command System (TT&C)
• Thermal Control System (TCS)
• Structural Subsystem

UHF Follow-On

• Features: Ultra High Frequency (UHF) two-way communications, Super High Frequency (SHF) for anti-jam, command and tracking.
• Specifications:
  • Weight: 2,600 pounds
  • Orbital altitude: Geosynchronous orbit (22,250 miles)
  • Power Plant: Two deployable solar array wings (approx. 2400 watts).
  • Launch Vehicle: Atlas-Centaur space booster
  • Mission Life: 14 years

Voyager 1 & 2

• Launched in 1977
• Initially designed to study Jupiter and Saturn, but later flew by Uranus and Neptune
• Mission extended - greater capabilities than initially planned

Ground Activities

• Spacecraft Flight Operations
• Payload Operations
• Payload Data Processing
• Payload Data Dissemination

Facilitated By:

• Real-Time Processing
• Payload Dissemination Infrastructure
• Powerful Payload Processing Facilities
• Mission Simulations

Launch

• Selection: Enough "throw weight," "cube" (volume), acceptable ride and good record.
• Integration: Launch loads, Mechanical/Electrical Integration, Understanding the Launch "flow" and count

Space System Development

• Mission Need (Why)
• Requirements Development (What)
• Derived Requirements (How): Mission orbit, Payload Types (communications, remote sensing, data relay), Spacecraft Design, Ground Facilities and Locations, Computers/Software, Personnel/Training, Launch Segments
• Note: The requirements generation process is iterative and involves compromises.

Spacecraft Development Process

• Waterfall (sequential)
• Spiral (iterative)
• Basic Sequence: Conceptual design, Detailed design, Develop detailed engineering models, Start production, Field system, Maintain until decommissioned, DoD mandates integrated, iterative product development process

Serial (Waterfall) Development

• Traditional process, follows a logical sequence from requirements analysis to operations
• Only way to develop very large scale systems (e.g., weapons, aircraft, spacecraft)
• Disadvantage: Obsolescence of technology, lack of customer involvement/feedback, difficult to adjust design once program proceeds

Concurrent versus serial development

• Concurrent development and manufacturing aim to optimize time to market and development productivity.
• Incorporates customer needs into predictable targets and ensures the target is met.
• Use simulation-led analysis, problem-solving to design out problems, validate designs before prototyping.
• Product testing ahead and concurrent with development programs to understand and quantify product performance before production.

Spiral Development

• Iterative process
• Evaluate alternatives, identify and resolve risks, develop, verify, and validate at each stage.
• Builds a little bit, testing a little bit; until the full system is created and is fully verified.

Systems Engineering

• A logical process for system development, includes: functional and physical decomposition of the system into logical parts, development of system requirements (system analysis, requirements development, interface requirements, requirements validation, test & demonstration, simulation, physical/functional configuration audits, integration & test planning, (Cradle to Grave lifecycle planning), disposal of satellites at end of life.

Systems Engineering Verification

• Requirements Management, System Analysis, Architecture Modeling, High-level design, Detailed design, Module Build, Acceptance testing, Compliance testing, System testing, Integration testing, Subsystem testing, Unit testing.

Spacecraft Integration and Test

• Methodical process to test spacecraft at different levels.
• Sequence: Component/unit tests, Integrate components into subsystems, Subsystem tests, Integrate subsystems into spacecraft, Spacecraft level tests, Integrate spacecraft into system, System test.

System Integration and Test (Types)

• Functional testing (Do subsystems work together?), Fit check, Environmental testing (Thermal vacuum, shock, vibration, Combined functional and environmental), Integrated functional testing (Do all segments work together?), Payload/system characterization (Space environment alteration and testing in space).
• Hardware in the loop, Simulation

Summary

• Functions (Mechanical, Electrical/Electronic, Process)
• Starts at component level, continues at subsystem level, and concludes with entire system test.

Design Verification and Qualification Testing

• Design Verification: Validate design precepts, examine limitations, build and test.
• Qualification: Determine system suitability, provide tools to measure customer success, allow time for repairs to meet requirements, potentially involving warranty periods

Types of Design/Qual Tests

• Functional: Life testing (structural, thermal, illumination, power cycling, radiation exposure), Component to System Level
• Structural: Static Tests, Dynamic Tests
• Thermal: Thermal cycling, Thermal vacuum

Launch Flow

• Pack and Ship (Spacecraft & Launcher)
• Establish Launch Operations
• Admin and Work Spaces for Launch Team
• Test to Ensure No Damage During Shipping
• Perform Subsystem and Spacecraft Tests
• Establish Communications
• Rehearsal, data and voice networks , Spacecraft Support

Review

• Segments of space system: Ground, Space, Launch
• Major subsystems of typical spacecraft
• Concept of systems engineering
• Spacecraft Integration and Test

Explore the foundational concepts of space systems in this introductory quiz for SN 209. The quiz covers essential components including ground, space, and launch segments, with a focus on the Tracking and Data Relay Satellite System (TDRSS) and spacecraft design. Test your knowledge of spacecraft operations and data processing.