AJAL.A.J Assistant Professor –Dept of ECE,

Federal Institute of Science And Technology (FISAT) TM 

MAIL: ec2reach@gmail.com

AstronauticsAstronautics

Reference Book

• Title: The Satellite Communication Applications Handbook

• Author: Bruce R. Elbert• ISBN: 1580534902 • EAN: 9781580534901• Publisher:

Artech House Publishers

Reference Books

• Title: Satellite Communications• Author: Dennis Roddy• ISBN: 0071371761 • EAN: 9780071371766• Publisher:

McGraw-Hill Professional

Reference Books

• Title: Satellite Communication Engineering• Author: Michael O. Kolawole• ISBN: 082470777X• EAN: 9780071371766• Publisher:

Marcel Dekker, Inc.

Pioneers in Satellite Communication

Konstantin Tsiolkovsky (1857 - 1935)Russian visionary of space flight First described the multi-stage rocket as means of achieving orbit.

  Hermann Noordung (1892 - 1929)

Postulated the geostationary orbit.

Arthur C. Clarke (1917 – 19 March 2008)Postulated the entire concept of international satellite telecommunications from geostationary satellite orbit including   coverage, power, services, solar eclipse. "Wireless World" (1945)

Satellite History CalendarSatellite History Calendar 1957 1957

• October 4, 1957: - First satellite - the Russian Sputnik 01October 4, 1957: - First satellite - the Russian Sputnik 01• First living creature in space: Sputnik 02First living creature in space: Sputnik 02

19581958• First American satellite: Explorer 01First American satellite: Explorer 01• First telecommunication satellite: This satellite broadcast a taped message: ScoreFirst telecommunication satellite: This satellite broadcast a taped message: Score

19591959• First meteorology satellite: Explorer 07First meteorology satellite: Explorer 07

19601960• First successful passive satellite: Echo 1First successful passive satellite: Echo 1• First successful active satellite: Courier 1BFirst successful active satellite: Courier 1B• First NASA satellite: Explorer 08First NASA satellite: Explorer 08

April 12, 1961: - First man in spaceApril 12, 1961: - First man in space 19621962

• First telephone communication & TV broadcast via satellite: Echo 1First telephone communication & TV broadcast via satellite: Echo 1• First telecommunication satellite, first real-time active, AT&T: Telstar 1First telecommunication satellite, first real-time active, AT&T: Telstar 1• First Canadian satellite: Alouette 1First Canadian satellite: Alouette 1• On 7On 7thth June 1962 at 7:53p the two-stage rocket; Rehbar-I was successfully launched from Sonmiani Rocket June 1962 at 7:53p the two-stage rocket; Rehbar-I was successfully launched from Sonmiani Rocket

Range. It carried a payload of 80 pounds of sodium and soared to about 130 km into the atmosphere. With Range. It carried a payload of 80 pounds of sodium and soared to about 130 km into the atmosphere. With the launching of Rehbar-I, Pakistan had the honour of becoming the third country in Asia and the tenth in the the launching of Rehbar-I, Pakistan had the honour of becoming the third country in Asia and the tenth in the world to conduct such a launching after USA, USSR, UK, France, Sweden, Italy, Canada, Japan and Israel. world to conduct such a launching after USA, USSR, UK, France, Sweden, Italy, Canada, Japan and Israel.

• Rehbar-II followed a successful launch on 9Rehbar-II followed a successful launch on 9thth June 1962 June 1962 19631963

• Real-time active: Telstar 2Real-time active: Telstar 2 19641964

• Creation of IntelsatCreation of Intelsat• First geostationary satellite, second satellite in stationary orbit: Syncom 3First geostationary satellite, second satellite in stationary orbit: Syncom 3• First Italian satellite: San Marco 1First Italian satellite: San Marco 1

Satellite History CalendarSatellite History Calendar 19651965

• Intelsat 1 becomes first commercial comsat: Early BirdIntelsat 1 becomes first commercial comsat: Early Bird• First real-time active for USSR: Molniya 1AFirst real-time active for USSR: Molniya 1A

19671967• First geostationary meteorology payload: ATS 3First geostationary meteorology payload: ATS 3

19681968• First European satellite: ESRO 2BFirst European satellite: ESRO 2B

July 21, 1969: - First man on the moonJuly 21, 1969: - First man on the moon

19701970• First Japanese satellite: OhsumiFirst Japanese satellite: Ohsumi• First Chinese satellite: Dong Fang Hong 01First Chinese satellite: Dong Fang Hong 01

19711971• First UK launched satellite: ProsperoFirst UK launched satellite: Prospero• ITU-WARC for Space Telecommunications ITU-WARC for Space Telecommunications • INTELSAT IV Launched INTELSAT IV Launched • INTERSPUTNIK - Soviet Union equivalent of INTELSAT formed INTERSPUTNIK - Soviet Union equivalent of INTELSAT formed

19741974• First direct broadcasting satellite: ATS 6First direct broadcasting satellite: ATS 6

1976 1976 • MARISAT - First civil maritime communications satellite service started MARISAT - First civil maritime communications satellite service started

1977 1977 • EUTELSAT - European regional satellite EUTELSAT - European regional satellite • ITU-WARC for Space Telecommunications in the Satellite Service ITU-WARC for Space Telecommunications in the Satellite Service

19791979• Creation of InmarsatCreation of Inmarsat

Satellite History CalendarSatellite History Calendar 1980 1980 

• INTELSAT V launched - 3 axis stabilized satellite built by Ford Aerospace INTELSAT V launched - 3 axis stabilized satellite built by Ford Aerospace 1983 1983 

• ECS (EUTELSAT 1) launched - built by European consortium supervised by ESA ECS (EUTELSAT 1) launched - built by European consortium supervised by ESA 1984 1984 

• UK's UNISAT TV DBS satellite project abandoned UK's UNISAT TV DBS satellite project abandoned • First satellite repaired in orbit by the shuttle: SMMFirst satellite repaired in orbit by the shuttle: SMM

19851985• First Brazilian satellite: Brazilsat A1First Brazilian satellite: Brazilsat A1• First Mexican satellite: Morelos 1First Mexican satellite: Morelos 1

19881988• First Luxemburg satellite: Astra 1AFirst Luxemburg satellite: Astra 1A

19891989  • INTELSAT VI - one of the last big "spinners" built by HughesINTELSAT VI - one of the last big "spinners" built by Hughes• Creation of Panamsat - Begins ServiceCreation of Panamsat - Begins Service• On 16 July 1990, Pakistan launched its first experimental satellite, BADR-I from China On 16 July 1990, Pakistan launched its first experimental satellite, BADR-I from China

1990 1990 • IRIDIUM, TRITIUM, ODYSSEY and GLOBALSTAR S-PCN projects proposed - CDMA designs more IRIDIUM, TRITIUM, ODYSSEY and GLOBALSTAR S-PCN projects proposed - CDMA designs more

popular popular • EUTELSAT II EUTELSAT II

1992 1992 • OLYMPUS finally launched - large European development satellite with Ka-band, DBTV and Ku-OLYMPUS finally launched - large European development satellite with Ka-band, DBTV and Ku-

band SS/TDMA payloads - fails within 3 years band SS/TDMA payloads - fails within 3 years 1993 1993 

• INMARSAT II - 39 dBW EIRP global beam mobile satellite - built by Hughes/British Aerospace INMARSAT II - 39 dBW EIRP global beam mobile satellite - built by Hughes/British Aerospace 1994 1994 

• INTELSAT VIII launched - first INTELSAT satellite built to a contractor's design INTELSAT VIII launched - first INTELSAT satellite built to a contractor's design • Hughes describe SPACEWAY design Hughes describe SPACEWAY design • DirecTV begins Direct Broadcast to HomeDirecTV begins Direct Broadcast to Home

19951995• Panamsat - First private company to provide global satellite services.Panamsat - First private company to provide global satellite services.

Satellite History CalendarSatellite History Calendar 1996 1996 

• INMARSAT III launched - first of the multibeam mobile satellites (built by GE/Marconi) INMARSAT III launched - first of the multibeam mobile satellites (built by GE/Marconi) • Echostar begins Diresct Broadcast ServiceEchostar begins Diresct Broadcast Service

1997 1997 • IRIDIUM launches first test satellites IRIDIUM launches first test satellites • ITU-WRC'97 ITU-WRC'97

1999 1999 • AceS launch first of the L-band MSS Super-GSOs - built by Lockheed Martin AceS launch first of the L-band MSS Super-GSOs - built by Lockheed Martin • Iridium Bankruptcy - the first major failure? Iridium Bankruptcy - the first major failure?

2000 2000 • Globalstar begins service Globalstar begins service • Thuraya launch L-band MSS Super-GSOThuraya launch L-band MSS Super-GSO

20012001• XM Satellite Radio begins serviceXM Satellite Radio begins service• Pakistan’s 2Pakistan’s 2ndnd Satellite, BADR-B was launched on 10 Dec 2001 at 9:15a from Baikonour Satellite, BADR-B was launched on 10 Dec 2001 at 9:15a from Baikonour

Cosmodrome, Kazakistan Cosmodrome, Kazakistan 20022002

• Sirius Satellite Radio begins serviceSirius Satellite Radio begins service• Paksat-1, was deployed at 38 degrees E orbital slot in December 2002, Paksat-1, was deployed Paksat-1, was deployed at 38 degrees E orbital slot in December 2002, Paksat-1, was deployed

at 38 degrees E orbital slot in December 2002at 38 degrees E orbital slot in December 2002 2004 2004 

• Teledesic network planned to start operationTeledesic network planned to start operation 2005 2005 

• Intelsat and Panamsat Merge Intelsat and Panamsat Merge • VUSat OSCAR-52 (HAMSAT) Launched VUSat OSCAR-52 (HAMSAT) Launched

20062006• CubeSat-OSCAR 56 (Cute-1.7) LaunchedCubeSat-OSCAR 56 (Cute-1.7) Launched• K7RR-Sat launched by California Politechnic UniversityK7RR-Sat launched by California Politechnic University

20072007• Prism was launched by University of Tokyo Prism was launched by University of Tokyo

20082008• COMPASS-1; a project of Aachen University was launched from Satish Dawan Space Center, COMPASS-1; a project of Aachen University was launched from Satish Dawan Space Center,

India. It failed to achieve orbit.India. It failed to achieve orbit.

What is a Satellite ?What is a Satellite ?

A satellite is basically any object that A satellite is basically any object that revolves around a planet in a circular or revolves around a planet in a circular or elliptical path.elliptical path.

satellites were exotic, top-secret devices. They satellites were exotic, top-secret devices. They were used primarily in a were used primarily in a military capacitymilitary capacity, for , for activities such as navigation and espionage.activities such as navigation and espionage.

Now they are an essential part of our daily Now they are an essential part of our daily

lives. We see and recognize their use in weather lives. We see and recognize their use in weather reports, television transmission by DIRECTV and reports, television transmission by DIRECTV and

the DISH Network, and everyday telephone callsthe DISH Network, and everyday telephone calls

How Is a Satellite Launched How Is a Satellite Launched into an Orbit?into an Orbit?

All satellites today get into orbit by All satellites today get into orbit by riding on a riding on a rocketrocket. .

  Orbital velocityOrbital velocity

  Orbital velocityOrbital velocity is the velocity  is the velocity needed to achieve balance between needed to achieve balance between gravity's pull on the satellite and gravity's pull on the satellite and the the inertiainertia of the satellite's motion  of the satellite's motion

-- the satellite's tendency to keep -- the satellite's tendency to keep going. going.

How Much Do Satellites Cost?How Much Do Satellites Cost?

a satellite launch can cost anywhere a satellite launch can cost anywhere between $50 million and $400 millionbetween $50 million and $400 million. .

hurricane-watch satellitehurricane-watch satellite  mission cost $290 million. mission cost $290 million.

missile-warning satellitemissile-warning satellite cost $682 million. cost $682 million.

NOTEa shuttle mission could easily carry several satellites into orbit

 Satellite

 Natural Satellite  Artificial Satellite

Whose Satellite Was the First to Orbit Earth?

• The Soviet Sputnik satellite was the first to orbit Earth, launched on Oct. 4, 1957.

Sputnik 1, the first satellite, shown with four whip antennas

Sputnik 2 - Mission

• Some scientists believed humans would be unable to survive the launch or the conditions of outer space, so engineers viewed flights by non-human animals as a

necessary precursor to human missions.

Laika was a Soviet space dog that became the first animal to orbit the Earth – as well as the first animal to die in orbit.

Manned spacecraft

• On 12 April 1961, aboard the Vostok 1, Yuri Gagarin became both the first human to travel into space, and the first to orbit the earth. 

• He founded the

Indian Space Research Organisation (ISRO). 

After Sarabhai died in 1971, the Vikram Sarabhai Space Center (VSSC) in Tiruvananthapuram is named for him. 

മല്ലി�ക സാ�രാ�ഭാ�യ്�

• The Padma Bhushan is the third highest civilian award in the Republic of India, after the Bharat Ratna and the Padma Vibhushan, but comes before the Padma Shri. It is awarded by the Government of India.

INDIAN SATELLITE

IN July 18, 1980,

India launched the satellite Rohini 1 on an Satellite Launch Vehicle (SLV) rocket from the Sriharikota Island launch site

Space station• A space station (or orbital station) is a spacecraft capable of

supporting a crew which is designed to remain in space (most commonly in low Earth orbit) for an extended period of time, and to which other spacecraft can dock.

Habitability

These stations have various issues that limit their long-term habitability, such as very low recycling rates, relatively high radiation levels and a lack of gravity. Some of these problems cause discomfort and long-term health effects. 

NB: Terms

• The path a satellite follows is an orbit.

• In the orbit, the farthest point from Earth is the apogee,

• and the nearest point is the perigee

Satellite categories

Orbits:• LEO: Low Earth Orbit.• MEO: Medium Earth Orbit• GEO: Geostationary Earth Orbit

Satellite orbit altitudes

Satellite frequency bands

• At the Geostationary orbit the satellite covers 42.2% of the earth’s surface.

• Theoretically 3 geostaionary satellites provides 100% earth coverage

Geostationary Communication Geostationary Communication Satellites in Orbit TodaySatellites in Orbit Today

Satellites in geostationary orbit

Satellite orbits

Geostationary Geostationary OrbitOrbit

Geostationary orbits

• Geostationary orbits

Polar OrbitPolar Orbit

What is the period of the Moon, according to Kepler’s law?

Example 16.1

Here C is a constant approximately equal to 1/100. The period is in seconds and the distance in kilometers.

According to Kepler’s law, what is the period of a satellite that is located at an orbit approximately 35,786 km above the Earth?

Example 16.2

SolutionApplying the formula, we get

base stationor gateway

Classical satellite systems

Inter Satellite Link (ISL)

Mobile User Link (MUL) Gateway Link

(GWL)

footprint

small cells (spotbeams)

User data

PSTNISDN GSM

GWL

MUL

PSTN: Public Switched Telephone Network

Inclination

inclination

satellite orbit

perigee

plane of satellite orbit

equatorial plane

Elevation

Elevation:angle between center of satellite beam and surface

minimal elevation:elevation needed at leastto communicate with the satellite

footprint

Link budget of satellites

Parameters like attenuation or received power determined by four parameters:

sending power

gain of sending antenna

distance between sender and receiver

gain of receiving antenna

Problems

varying strength of received signal due to multipath propagation

interruptions due to shadowing of signal (no LOS)

Possible solutions

Link Margin to eliminate variations in signal strength

satellite diversity (usage of several visible satellites at the same time) helps to use less sending power

24

c

frL

L: Lossf: carrier frequencyr: distancec: speed of light

Atmospheric attenuation

Example: satellite systems at 4-6 GHz

elevation of the satellite

5° 10° 20° 30° 40° 50°

Attenuation of the signal in %

10

20

30

40

50

rain absorption

fog absorption

atmospheric absorption

Four different types of satellite orbits can be identified depending on the shape and diameter of the orbit:

GEO: geostationary orbit, ca. 36000 km above earth surface

LEO (Low Earth Orbit): ca. 500 - 1500 km

MEO (Medium Earth Orbit) or ICO (Intermediate Circular Orbit): ca. 6000 - 20000 km

HEO (Highly Elliptical Orbit) elliptical orbits

Orbits I

Orbits II

earth

km35768

10000

1000

LEO (Globalstar,

Irdium)

HEO

inner and outer VanAllen belts

MEO (ICO)

GEO (Inmarsat)

Van-Allen-Belts:ionized particles2000 - 6000 km and15000 - 30000 kmabove earth surface

Geostationary satellites

Orbit 35,786 km distance to earth surface, orbit in equatorial plane (inclination 0°)

complete rotation exactly one day, satellite is synchronous to earth rotation

fix antenna positions, no adjusting necessary

satellites typically have a large footprint (up to 34% of earth surface!), therefore difficult to reuse frequencies

bad elevations in areas with latitude above 60° due to fixed position above the equator

high transmit power needed

high latency due to long distance (ca. 275 ms)

not useful for global coverage for small mobile phones and data transmission, typically used for radio and TV transmission

LEO systems

Orbit ca. 500 - 1500 km above earth surfacevisibility of a satellite ca. 10 - 40 minutesglobal radio coverage possible latency comparable with terrestrial long distance

connections, ca. 5 - 10 mssmaller footprints, better frequency reusebut now handover necessary from one satellite to another many satellites necessary for global coverage more complex systems due to moving satellites

Examples: Iridium (start 1998, 66 satellites)

Bankruptcy in 2000, deal with US DoD (free use, saving from “deorbiting”)

Globalstar (start 1999, 48 satellites) Not many customers (2001: 44000), low stand-by times for mobiles

MEO systems

Orbit ca. 5000 - 12000 km above earth surface

comparison with LEO systems:

slower moving satellites

less satellites needed

simpler system design

for many connections no hand-over needed

higher latency, ca. 70 - 80 ms

higher sending power needed

special antennas for small footprints needed

Example:

ICO (Intermediate Circular Orbit, Inmarsat) start ca. 2000 Bankruptcy, planned joint ventures with Teledesic, Ellipso – cancelled

again, start planned for 2003

Handover in satellite systems

Several additional situations for handover in satellite systems compared to cellular terrestrial mobile phone networks caused by the movement of the satellites Intra satellite handover

handover from one spot beam to another mobile station still in the footprint of the satellite, but in another cell

Inter satellite handover handover from one satellite to another satellite mobile station leaves the footprint of one satellite

Gateway handover Handover from one gateway to another mobile station still in the footprint of a satellite, but gateway leaves the

footprint Inter system handover

Handover from the satellite network to a terrestrial cellular network mobile station can reach a terrestrial network again which might be

cheaper, has a lower latency etc.

What’s on a satellite?What’s on a satellite? Communications

Power

Sensors/Instruments “Bus”

How Satellites WorkHow Satellites Work

1.1. A Earth Station sends A Earth Station sends message in GHz range. message in GHz range. (Uplink) (Uplink)

2.2. Satellite Receive and Satellite Receive and retransmit signals back. retransmit signals back. (Downlink)(Downlink)

3.3. Other Earth Stations Other Earth Stations receive message in receive message in useful strength area. useful strength area. (Footprint)(Footprint)