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- 1. International University of Rabat School of Aerospace Engineering Course S lli Satellites Pr Adnane ADDAIM Presented by : Pr. Adnane ADDAIM adnane.addaim@uit.ac.ma Academic year 2019/2020
- 2. Pr. A. Addaim UIR/SAE Plan Chapter 1 : Introduction to satellites C apte : t oduct o to sate tes Chapter 2 : Satellites Platform p Chapter 3 : Satellites Payload Chapter 4 : Satellite Application 2
- 3. Pr. A. Addaim UIR/SAE Plan Chapter 1 : Introduction to satellites Chapter 1 : Introduction to satellites Introduction History D fi i i Definitions O bit Orbits Space Environnment Space Environnment 3
- 4. Pr. A. Addaim UIR/SAE Introduction Satellites have become in 50 years an important element of human activity: state policy (prestige, supremacy), object of international cooperation: Defense Science, from the knowledge of the universe to that of the planet Earth Irreplaceable role in the services of everyday life: Telecommunications P i t t i t di t t l i i Point-to-point direct television Telephony: international, intercontinental, mobile communication, portable ... Multimedia: Internet, telecommuting, telemedicine Navigation Navigation Remote sensing, Earth observation Meteorology The spatial activity must combine: Technological achievement and innovation Q lit d f t ith t ffi i li bilit d il bilit 4 Quality and safety, with management efficiency, economy, reliability and availability
- 5. Pr. A. Addaim UIR/SAE History 1945 : The writer Arthur C. Clarke published an article which theoretically proposed the feasibility of establishing a communication satellite in a geostationary orbit. 1957 : Sputnik-1 was the first artificial satellite Launched on 4 October by the former Soviet Union followed by Sputnik-2 on 3 November carried a dog named Laika. 1958 : Explorer-1 was the first satellite launched by the United States on 31 January. 1958 : The Vanguard-1 was the first satellite to employ solar cells to charge the batteries batteries. 1960 : The TIROS-1 satellite provided the first pictures of Earth. 1965 Th I l 1 k ‘E l Bi d’ h fi i 1965 : The Intelsat-1 known as ‘Early Bird’ was the first geostationary communications satellite in commercial service. 1965 : Molniya series of satellites beginning were unique in providing uninterrupted 1965 : Molniya series of satellites beginning were unique in providing uninterrupted 24 hours a day communications services without being in the conventional geostationary orbit. 5 1994 : The first digital satellite TV broadcasting began in the United States of America
- 6. Pr. A. Addaim UIR/SAE Definitions Aerospace Flight Vehicles A ti Aeronautic aircraft, helicopter, aero-boat (airship) ，hot air balloon missiles (air to air; air to ground; ground to air; cruise) Astronautic - Spacecraft : satellite (95% of spacecraft), probe, spaceship space station - Launcher : - Launcher : launch vehicle, ballistic missile Space Shuttle 6
- 7. Pr. A. Addaim UIR/SAE Definitions A i E S A ’ l h hi l Ariane: European Space Agency’s launch vehicle Astronaut: A space traveller, i.e. a person who flies in space either as a crew member or a passenger Astroph sics St d of the ph sical and chemical nat re of celestial bodies and their Astrophysics: Study of the physical and chemical nature of celestial bodies and their environments Buran: A re-usable launch vehicle, Russian counterpart of a space shuttle Footprint: The area of coverage of a satellite Footprint: The area of coverage of a satellite Geostationary orbit: An equatorial circular orbit in which the satellite moves from west to east with a velocity such that it remains stationary with respect to a point on the Earth Also known as the Clarke orbit after the name of the science fiction writer the Earth. Also known as the Clarke orbit after the name of the science fiction writer who first proposed this orbit Geostationary Earth orbit (GEO): A satellite orbit with an orbit height at 35 786 km above the surface of the Earth. This height makes the satellite’s orbital velocity equal above the surface of the Earth. This height makes the satellite s orbital velocity equal to the speed of rotation of Earth, thus making the satellite look stationary from a given point on the surface of the Earth GPS: An abbreviation for the global positioning system. It is a satellite-based g p g y navigation system that allows you to know your position coordinates with the help of a receiver anywhere in the world under any weather condition Injection velocity: This is the horizontal velocity with which a satellite is injected into 7 space by the launch vehicle with the intention of imparting a specific trajectory to the satellite
- 8. Pr. A. Addaim UIR/SAE Definitions INTELSAT A f I t ti l T l i ti S t llit C ti INTELSAT: Acronym for International Telecommunications Satellite Consortium operating satellites internationally for both domestic and international telecommunication services Landsat First remote sensing satellite series in the orld from USA Landsat: First remote sensing satellite series in the world from USA Low Earth orbit (LEO): A satellite orbit with an orbital height of around 150 km to 500 km above the surface of Earth. These orbits have lower orbital periods, shorter propagation delays and lower propagation losses propagation delays and lower propagation losses Medium Earth orbit (MEO): A satellite orbit with an orbital height around 10 000 km to 20 000 km above the surface of the Earth Molniya orbit: A highly inclined and elliptical orbit used by Russian satellites with Molniya orbit: A highly inclined and elliptical orbit used by Russian satellites with apogee and perigee distances of about 40 000 and 500 km and an orbit inclination of 65◦. Three such satellites aptly spaced apart in the orbit provide an uninterrupted communication service communication service NASA: National Aeronautics and Space Administration Payload: Useful cargo-like satellite being a payload of a launch vehicle Satellite: A natural or artificial body moving around a celestial body y g y Sounding rocket: A research rocket used to obtain data from the upper atmosphere Space shuttle: A re-usable launch vehicle from the United States Transponder: A piece of radio equipment that receives a signal from the Earth station 8 at the uplink frequency, amplifies it and then retransmits the same signal at the downlink frequency
- 9. Pr. A. Addaim UIR/SAE Definitions Satellite Applications Communication Navigation remote sensing Sat applications Sat applications Scientific experiments remote sensing Military applications 9
- 10. Pr. A. Addaim UIR/SAE Definitions S ll/Mi / S ll/Mi /N N S t llit S t llit Small/Micro/ Small/Micro/Nano Nano Satellites Satellites Small sat 500～1000 kg Mini-sat 100 ～ 500 kg Micro-sat 10 ～ 100 kg Nano-sat 1～10 kg Pico-sat 0.1~1 kg 500 1000 kg 20～50 M$ g 4～20 M$ g 1～4 M$ g <1 M$ 0.1 1 kg <1 M$ 10
- 11. Pr. A. Addaim UIR/SAE Definitions Satellites Project Life Cycle FORMULATION IMPLEMENTATION A B C D E F Pre-A Satellites Project Life Cycle Project Phases Concept Studies Concept & Technology Development Preliminary Design & Technology Completion Final Design & Fabrication System Assembly, Test, & Launch Closeout Operations & Sustainment Key Decision P i t A C D E B F Points Major Mission Concept Review Systems Requirements Review Mission/System Definition Review j Reviews Mission/System Definition Review Critical Design Review Systems Integration Review Preliminary Design Review Independent Cost Systems Integration Review Operational Readiness Review Flight Readiness Review Post Launch Assessment Review Independent Cost Estimates 11 Decommissioning Review
- 12. Pr. A. Addaim UIR/SAE Definitions C tit ti f t llit Constitution of satellite Satellite l d Platform payloads Platform Communication satellite On Bo The St m Pow Attitu Con Propu TC Communication satellite (Transponders + antennas) Navigation satellite (Distance measurements and time oard Com System rmal Co System ructure mechanis wer Sys ude and ntrol Sy ulsion S CC Syst measurements and time system) Visible light reconnaissance mputer m ontrol m and sm stem d Orbit ystem System tem satellite (Cameras) Weather satellite (Sensors) 12 Scientific experimental satellite (Experimental facilities)
- 13. Pr. A. Addaim UIR/SAE Definitions Satellite System It i t f th l t - It consists of three elements : The launch The space segment Satellite : Platform and Payload Satellite : Platform and Payload Control station : Means of operations and commands The user segment (Ground) Earth station : Means of programming the payload p g g p y (Mission centre) Means of reception, processing, storage, broadcasting of i f i l d h l d i i h h 13 information related to the payload, insuring the access the global user segment.
- 14. Pr. A. Addaim UIR/SAE Definitions Satellite System : The Launch The launch vehicle is the first condition for satellite to gain access to the orbit: it constraints very strongly the access to space: orbit reached, mass in orbit, injection speed, CAP volume available It has long been at the heart of the States' space strategy The main monopolies of the 1st space powers Ariane is a major element of the independence of Europe Today, strong competition for an activity whose commercial character has exceeded the strategic character: release of certain g constraints, but need of standardization of the interfaces. 14
- 15. Pr. A. Addaim UIR/SAE Definitions Launches by country Launches by family of launch vehicle 15
- 16. Pr. A. Addaim UIR/SAE Definitions Platform classes 500 tonnes > 5 tonnes International Space Station Big GEO Alphabus Eurostar-Spacebus > 5 tonnes 3 to 5 tonnes 1 to 3 tonnes 500 kg Big GEO GEO télécom and MEO MEO, GEO Mini Alphabus Eurostar Spacebus Eurostar – Spacebus Spot Protéus 500 kg 100 kg 10 kg Mini Micro Nano Protéus Myriade 16
- 17. Pr. A. Addaim UIR/SAE Definitions Satellite classes Manufacture Platform Launch Mass Electric Power Geostationary satellite (Lifetime of 15 years) numbers given for illustrative purposes only Mass ASPI Spacebus 4000 5500 kg 15 to 20 kW AIRBUS defence and space Eurostar 3000 5500 kg 15 kW Boeing BSS 601 BSS 702 + classe 5800 kg 5 to 25 kW Loockheed- Martin A2100 Ax A2100 Ax2 Advanced A2100 4400 à 5500 kg 6 to 22 kW 17 Loral 1300S 6200 kg 11 to 19 kW
- 18. Pr. A. Addaim UIR/SAE Definitions Mass distributions aboard satellite satellite Mass distributions in % Earth observation Telecom GEO satellite (SPOT) , lifetime of 5 years satellite, lifetime of 15 years Platform 40 35 Payload 54 10 propellants 6 55 18
- 19. Pr. A. Addaim UIR/SAE Definitions Economic context : the satellite manufactures Two European satellite manufactures Airbus et Thales face three American manufactures in the commercial field: Boeing Lockheed American manufactures in the commercial field: Boeing, Lockheed Martin and SSL Loral 19
- 20. Pr. A. Addaim UIR/SAE Definitions Economic context : the satellite manufacturing revenues g 20
- 21. Pr. A. Addaim UIR/SAE Definitions Economic context : the Costs Cost of a telecommunications satellite system in open competition 21
- 22. Pr. A. Addaim UIR/SAE Definitions Economic context : the Costs Satellite Cost Project Management : Engineering, product insurance, Financial expenses Payload : Repeaters + Antennas 22 y p Platform : Material and supply tracking
- 23. Pr. A. Addaim UIR/SAE Orbits Space Law “First Come First Ser ed” United Nations Outer Space Treaty (1967) “First Come, First Served” p y ( ) Outer space free for exploitation and use by all states in conformity with international regulations conformity with international regulations States retain jurisdiction and control over objects they have launched into outer space have launched into outer space International Telecommunication Union Radio frequencies & satellite orbits are limited natural resources Principles of use of orbit/spectrum 23 Principles of use of orbit/spectrum Allocation of frequency bands
- 24. Pr. A. Addaim UIR/SAE Orbits Operating Satellite database htt // / l / / t llit d t b 24 https://www.ucsusa.org/nuclear-weapons/space-weapons/satellite-database
- 27. Pr. A. Addaim UIR/SAE Orbits G m2 Two body problem In a Galilean frame, the equations of motion of the two particles are written by m1 3 1 2 1 2 2 1 1 1 r r r r m Gm r m motion of the two particles are written by 1 2 r r 3 2 1 2 1 1 2 2 2 r r r r m Gm r m 2 r 1 r O By adding the two previous equations of motion, we have: te cons r tan By Subtracting the two previous previous equations of motion and using : te cons rG tan g ) ( r G 1 2 r r r 27 3 2 1 ) ( r m m G r
- 28. Pr. A. Addaim UIR/SAE Orbits In astronomy, Kepler's laws of planetary motion are three KEPLER Orbit y, p p y scientific laws describing the motion of planets around the Sun: The orbit of a planet is an ellipse with the Sun at one of the two foci the two foci A line segment joining a planet and the Sun sweeps out l d i l i t l f ti equal areas during equal intervals of time The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit Restricted two body problem conforms to the Kepler’s law, so 28 y p p its orbit is called Kepler orbit.
- 29. Pr. A. Addaim UIR/SAE Orbits Spacecraft is free to move without control Assumptions for KEPLER Orbit Spacecraft is free to move without control. The Earth is a sphere with uniform mass distribution. Th i i f h l i l b di id d The gravities of other celestial bodies are not considered. Other disturbances, such as atmospheric drag and solar di i l d radiation pressure, are neglected. The mass of the Earth is much larger than h f h f the mass of the spacecraft. The property of the relativity theory i id d is not considered. 29
- 30. Pr. A. Addaim UIR/SAE Orbits Spacecraft Orbits: U i th ti f KEPLER O bit th Using the assumptions for KEPLER Orbit, the acceleration of the spacecraft is given by : 3 r r GM r r 3 characteristic constants can be obtained: 3 characteristic constants can be obtained: 1. Specific relative angular momentum ܪ p g 2. Energy ܧ 3. Laplace vector ܮ 30
- 54. Pr. A. Addaim UIR/SAE Orbits E i 1 Exercise 1 A satellite is orbiting Earth in a uniform circular orbit at a height of 630 k f th f f E th A i th di f E th d it 630 km from the surface of Earth. Assuming the radius of Earth and its mass to be 6370 km and 5.98 × 1024 kg respectively, determine the velocity of the satellite (Take the gravitational constant G = 6.67 × 10−11Nm2/kg2). Exercise 2 The apogee and perigee distances of a satellite orbiting in an elliptical p g p g g p orbit are respectively 45 000 km and 7000 km. Determine the following: 1. Semi-major axis of the elliptical orbit 2. Orbit eccentricity 3. Distance between the centre of the Earth and the centre of the elliptical orbit E i 3 Exercise 3 A satellite is moving in an elliptical orbit with the major axis equal to 42 000 k If th i di t i 8000 k fi d th d th bit 54 km. If the perigee distance is 8000 km, find the apogee and the orbit eccentricity.
- 55. E i 4 Pr. A. Addaim UIR/SAE Orbits Exercise 4 Refer to Figure below. Satellite A is orbiting Earth in a near-Earth circular bit f di 7000 k S t llit B i biti E th i lli ti l bit ith orbit of radius 7000 km. Satellite B is orbiting Earth in an elliptical orbit with apogee and perigee distances of 47 000 km and 7000 km respectively. Determine the velocities of the two satellites at point X.
- 56. E i 5 Pr. A. Addaim UIR/SAE Orbits Exercise 5 Refer to Figure below. Satellite A is orbiting Earth in an equatorial circular bit f di 42 000 k S t llit B i biti E th i lli ti l bit orbit of radius 42 000 km. Satellite B is orbiting Earth in an elliptical orbit with apogee and perigee distances of 42 000 km and 7000 km respectively. Determine the velocities of the two satellites at point X.
- 57. E i 6 Pr. A. Addaim UIR/SAE Orbits Exercise 6 Refer to Figure below. Satellite A is orbiting Earth in a circular orbit of di 25 000 k S t llit B i biti E th i lli ti l bit ith radius 25 000 km. Satellite B is orbiting Earth in an elliptical orbit with apogee and perigee distances of 43 000 km and 7000 km respectively. Determine the velocities of the two satellites at the indicated points X and Y.