Prüfung Flashcards
Segments of a satellite mission
Space segment
- Satellite
- Orbit & Constellation
- Communication Architecture
Launch Segment
-Launch
Ground Segment
- Ground Stations
- Mission control center & mission operations
- Data processing, archiving & distribution
Program segment
- Objectives / Mission concept
- User
Phase 0:
Mission analysis/identification of requirements.
main outputs:
identification and characterization of…
• the proposed mission,
• user needs and expected performance
• mission constraints,
• definition of possible system concepts
• first assessment of project management (organisation, costs, schedules).
Phase A:
Feasibility phase:
Refinement (genauer definieren) of the needs expressed in phase 0.
main outputs:
• Critical mission elements, quantity and type
• Function tree of the mission,
• Evaluation various possible system concepts
• Determination of uncertainty and mission risks
• Discussion of the technical and industrial feasibility
At end: Preliminary Requirements Review (PRR) -> system concept selection
Phase B:
Preliminary design of the mission
Main tasks:
• Selection of technical solutions for the system concept
• Precise and coherent definition (performance levels, costs, schedules) at every level
• Product tree and products specifications,
• Identification of ‘Make or buy’ alternatives,
• Confirmation of the feasibility of the proposed solution
• Definition of mission risks and fall back options
• Assessment of manufacturing, production and operating costs
• Reliability and safety assessment,
At end: Preliminary Design Review (PDR)
Phase C:
Detailed design of the mission
main issues:
• Detailed definition and detailed design of the system and its components,
• Final ‘make or buy’ decision for the products,
• Confirmation of the set-up, test and qualification conditions,
• Final definition of the methods and means of production and verification,
• Procurement of the Production Master File,
• Production of the first models of the system,
• Development of interfaces within the configuration
• Preparation of phase E activities.
phase results in acceptance of Production Master File
Phase D:
Production and ground qualification testing
Phase D is the end of the system development.
goal at end: Production Master File and operational documentation
main objects:
• a qualified definition of the products, components and the system itself
• production of material, software and components
• confirmation and qualification of methods, procedures, production and verification
• manufacture, assembly, integration and verification, to conduct the Qualification Reviews,
• Ground qualification testing (design qualification and operational qualification).
end: Acceptance Review (AR), which comprises all mission elements.
Phase E:
Utilisation phase
- launch campaign
- launch and in-flight acceptance of the satellites,
- operation and maintenance of the system.
Is often divided into two sub-phases:
• sub-phase E1: overall test and commissioning phase of the system
• sub-phase E2: utilisation phase itself
Phase F:
- covers all events from the end-of-life till final disposal of the product
- protected space regions beachten
- European Code of Conduct for Space Debris Mitigation: max. 25 jahre nach missionsende weg
This can be achieved by:
- direct re-entry of the space system (aktiv)
- limiting the orbital lifetime to less than 25 years after operational phase (passiv)
- transferring the space system to a graveyard orbit
Phases of a project and results
Phase -> result
System idea -> project plan
system concept, system development -> implementation concept, project proposal
system implementation & test -> developement & tested system
system use -> utilized system, results
system disposal -> final report, disposal
ESA buget 2019:
- gesamt-€
- Länder erste 4 (mit %)
- Domain erste 5 (mit %)
gesamt: 5,72 Mia € / 6 billion
FR 28%
D 22%
IT 10%
GB 8,8%
domain: Earth Observation 24% Space Transportations/Launchers 22% Navigation 13% Human Spaceflight, Micro. & Exploration 12% Scientific Programmes 9%
ESA Branches
Headquarters in Paris
ESTEC - Euopean Space Research and Technology Centre
-> Noordwijk (Netherlands)
EAC - Euopean Astronaut Centre
-> Köln
ESOC - Euopean Space Operations Centre
-> Darmstadt
ESRIN - European Space Research Institute
-> Frascati (Italy)
ESAC – European Space Astronomy Centre
-> Villafranca (Spain)
Guiana Space Center
Very first Mission statement includes
- Motivation
- mission statement or mission idea
- user or user groups
system drivers
= mission parameters
determine:
- > performance of mission
- > cost
- > risk
- > time schedule
!: are not constraints
Design process of satellite systems
Mission design | Payload definition -> Iteration Loop: 1. design drivers 2. choice of orbit 3. power management 4. attitude managemet 5. orbit management 6. propulsion 7. TT&C 8. onboard data handling & storage 9. structrure & mechanisms 10. thermal management 11. choice of launch vehicle 12. space & launch environment 13. product assurance 14. developement & test philosophy
Basic functions of space flight operations: list the 4 main fields (no detail)
- mission planning
- mission operations
- instruction and training of personnel
- scientific and technical support
basic functions of space flight operations: mission planninge
- user requirements
- scedule for ground station operations
- preperation of command files
- support of user requests
- calculation of orbit parameters
- operation of networks
- analysis of workload and efficiency
basic functions of space flight operations: mission operations
- commanding the spacecraft
- monitering of subsystems
- payload management
- operation of recording devices
- problem solving, handling of anomalies
- spacecraft trend analysis
basic functions of space flight operations: instruction and training of operating personnel
- design of instruction course
- training at simulator
- training at spacecraft
- ongoing advanced training
basic functions of space flight operations: scientific-technical support
- construction and test
- planning of orbit maneuvers
- management of subsystems
- payload management
- energy management
- problem solving, handling of anomalies
- service and maintanance of flight software
- service and maintanance of the simulaor (if available)
- maintanace of ground station database
- trend analysis for the spacecraft
Typical functionality of a ground station
- satellite radio frequency link
- satellite monitoring & control
- orbital dynamics
- traffic monitoring (making sure no one can access data that shouldn’t)
- in orbit testing
- station monitoring & control
- data archiving
- satellite & station database
- authentication
Mission Planning System: describe diagram (star)
Middle: mission planning tools
Input:
- current requirements -> mission scenario
- flight operation schedule, flight procedures
interacting: - spacecraft simulator - offline analysis system: > spacecraft data > payload data > flight dynamics > orbit analysis
output: timeline
telecommand system: describe diagram
Middle: Preperations of flight procedures
input: human machine interface (for command input)
interacting:
- timeline, flight operation schedule, flight procedures
- TC database (with available telecommands and their format)
output:
- > interpreter (does it make sense?), executer
- > data link system
before sending the commands to satellite what must be done?
- validation:
- > checking of commands prior to sending
- parameters provided?
- parameters withing valid range?
- command sequenz in correct order?
- time-tagged correct?
- verification
- > checking of correct command reception and execution
- recieved correctly (checksum)?
- correct order (timesum)?
- adressed correctly?
- does the target accept the command? is the command logical (e.g. TC and parameters are correct but device is in rong mode)?
- was requested function executed (TM check, e.g. ON/OFF state)?
telemetry system: describe diagram
middle: telemetry processor
input: data link system -> telemetry interface ->
output:
- telemetry viewer (graphical interface for operator)
- archive system (storage)
interacting:
- TM database (includes the format of each telemetry packet. from that, the TM processor knows how to split the recieved packets into the various TM values)
Jobs of TM processor:
- checks whether data is recieved correctly
- splits recieved packets into single TM values
- stores the data in archive system
- sends data to TM viewer
