Science and Technology in Modern India- V

Types of Satellites

• In the context of spaceflight, a satellite is an object that has been intentionally placed into orbit.
• These objects are called artificial satellites to distinguish them from natural satellites such as Earth's Moon.
• Here, we classified artificial satellites by the purpose.

I. Communication Satellites

• The Indian National Satellite (INSAT) system is one of the largest domestic communication satellite systems in Asia-Pacific region with nine operational communication satellites placed in Geo-stationary orbit.

• Established in 1983 with commissioning of INSAT-1B, it initiated a major revolution in India’s communications sector and sustained the same later. 

II. Earth Observation Satellites

• Starting with IRS-1A in 1988, ISRO has launched many operational remote sensing satellites.
• Today, India has one of the largest constellations of remote sensing satellites in operation.
• Currently, eleven operational satellites are in orbit – RESOURCESAT-1 and 2; CARTOSAT-1, 2, 2A, 2B; RISAT-1 and 2; OCEANSAT-2; Megha-Tropiques and SARAL.

• Varieties of instruments have been flown onboard these satellites to provide necessary data in a diversified spatial, spectral and temporal resolutions to cater to different user requirements in the country and for global usage.
• The data from these satellites are used for several applications covering agriculture, water resources, urban planning, rural development, mineral prospecting, environment, forestry, ocean resources and disaster management.

 III. Experimental Satellites

• ISRO has launched many small satellites mainly for experimental purposes.
• This experiment includes Remote Sensing, Atmospheric Studies, Payload Development, Orbit Controls, recovery technology etc.

IV. Navigation Satellite

• To meet the Civil Aviation requirements, ISRO is working jointly with Airport Authority of India in establishing the GPS Aided Geo Augmented Navigation (GAGAN) system.
• To meet the user requirements of the positioning, navigation and timing services based on the indigenous system, ISRO is establishing a regional satellite navigation system called Indian Regional Navigation Satellite System (IRNSS).

(i) GPS Aided GEO Augmented Navigation (GAGAN)

• This is a Satellite Based Augmentation System (SBAS) implemented jointly with Airport Authority of India (AAI).
• The main objectives of GAGAN are to provide Satellite-based Navigation services with accuracy and integrity required for civil aviation applications and to provide better Air Traffic Management over Indian Airspace.

• The system will be interoperable with other international SBAS systems and provide seamless navigation across regional boundaries.
• The GAGAN Signal-In-Space (SIS) is available through GSAT-8 and GSAT-10.

(ii) Indian Regional Navigation Satellite System (IRNSS)

• This is an independent Indian Satellite based positioning system for critical National applications.
• The main objective is to provide Reliable Position, Navigation and Timing services over India and its neighbourhood, to provide fairly good accuracy to the user.

• The IRNSS will provide basically two types of services:
  • Standard Positioning Service (SPS)
  • Restricted Service (RS)

V. Scientific & Exploration

• Indian space programme encompasses research in areas like astronomy, astrophysics, planetary and earth sciences, atmospheric sciences and theoretical physics.
• Balloons, sounding rockets, space platforms and ground-based facilities support these research efforts.
• A series of sounding rockets are available for atmospheric experiments.
• Several scientific instruments have been flown on satellites especially to direct celestial X-ray and gamma-ray bursts.

Major milestones in Indian Space Programme

• Indian Space Programme began at Thumba Equatorial Rocket Launching Station (TERLS) located at Thumba near Thiruvanathapuram.
• On November 21, 1963, the first sounding rocket was launched from TERLS.
• The first rocket, a Nike-Apache was procured from the US.

• A sounding rocket is a rocket, which is intended for assessing the physical parameters of the upper atmosphere.
• The Satellite Telecommunication Earth Station was set up at Ahmedabad on January 1, 1967.
• India’s first indigenous sounding rocket, RH-75, was launched on November 20, 1967.
• The first Indian satellite, Aryabhata, was launched by Soviet Union in 1975 for research in x-ray astronomy and solar physics.

• During 1975-76, ISRO along with NASA developed means of using space communications system for TV broadcasting.
• This resulted in the creation of the project Satellite Instructional Television Experiment (SITE).
• During January 1, 1977 to January 1, 1979, Satellite Telecommunication Experiments Project (STEP), a joint project of ISRO-and Post and Telegraphs Department (P&T) using the Franco-German Symphonie satellite was taken up.
• Bhaskara-I - an experimental satellite for earth observations was launched on June 7, 1979.
• First Experimental launch of SLV-3 with Rohini Technology Payload on board (August 10, 1979) but Satellite could not be placed in orbit.
• Satellite Launch Vehicle-3 (SLV-3) was the first launch vehicle of India.
• Second Experimental launch of SLV-3, Rohini satellite was successfully placed in orbit. (July 18, 1980).

• Ariane Passenger Payload Experiment (APPLE), an experimental geo-stationary communication satellite was successfully launched on June 19, 1981.

• It became the forerunner for future communication satellite system.
• Indian National Satellite system (INSAT)-1A was launched on April 10, 1982.
• This system was for communication, broadcasting and meteorology.
• On April 2, 1984, the first Indo-Soviet manned space mission was launched.
• Rakesh Sharma became the first Indian citizen to go into space.

• He flew aboard in the Soviet rocket Soyuz T-11, as part of a three-member Soviet-Indian crew.
• On March 24, 1987, the first developmental launch of Augmented Satellite Launch Vehicle (ASLV), that supported a larger payload than the SLV-3, waslaunched. It was meant to be low-cost.
• The first operational Indian Remote Sensing Satellite, IRS-1A was launched on March 17, 1988.
• Second developmental launch of Polar Satellite Launch Vehicle (PSLV) with IRS-P2, on board took place on October 15, 1994.

• This Satellite was successfully placed in Polar Sun synchronous Orbit.
• The first developmental launch of Geosynchronous Satellite Launch Vehicle (GSLV)-D1 with GSAT-1 on board took off from Sriharikota on April 18, 2001.
• It was developed keeping in mind the heavier and more demanding Geosynchronous communication satellites.
• The South Asia Satellite (GSAT-9) is a geosynchronous communications satellite by ISRO for the South Asian Association for Regional Cooperation (SAARC) region.

• The satellite was launched on 5 May 2017.
• INSAT-4CR weighing 2130 kg and launched by GSLV-F04 on September 2, 2007 is the heaviest satellite launched from India on the date.
• PSLV-C11 successfully launched CHANDRAYAAN-1 from Sriharikota on October 22, 2008.

• Chandrayaan-1 is the first Indian planetary science and exploration mission and it was operational for 312 days till August 28, 2009.
• November 5, 2013 - PSLV - C25 successfully launched Mars Orbiter Mission (Mangalyaan) Spacecraft from Sriharikota.

• On February 15, 2017, PSLV-C37, the 39^th mission of the workhorse launch vehicle of ISRO, injected ISRO’s Cartosat-2 Series Satellite weighing 714 kg and two ISRO Nano-satellites namely INS-1A, INS-1B and 101 Nano-satellites, from six foreign countries into a Sun-Synchronous Orbit.

• PSLV-C38/Cartosat-2 Series Satellite Mission was launched on June 23, 2017 from Sriharikota.

• On Jun 23, 2017, India's Polar Satellite Launch Vehicle, in its 40^th flight (PSLV-C38), launched the Cartosat-2 series satellite for earth observation and 30 co-passenger satellites together into a 505 km polar Sun Synchronous Orbit (SSO).
• India's latest communication satellite, GSAT-17 was inducted into the INSAT/GSAT system on June 29, 2017 from Kourou, French Guiana by Ariane-5 VA-238.
• This GSAT-17 carried Payloads in Normal C-band, Extended C-band and S-band to provide various communication services.
• GSAT-17 also carried equipment for meteorological data relay and satellite-based search and rescue services being provided by earlier INSAT satellites.
• India's Polar Satellite Launch Vehicle, in its 42^nd flight (PSLV-C40), successfully launched the Cartosat-2 Series Satellite for earth observation and 30 co-passenger satellites.
• PSLV-C40/Cartosat-2 Series Satellite Mission was launched on Jan 12, 2018.

• GSLV -F08 / GSAT-6A Mission was launched on March 29, 2018.
• It is the 12^th flight of Geosynchronous Satellite Launch Vehicle (GSLV) and Sixth flight with indigenous Cryogenic Stage.
• India's Polar Satellite Launch Vehicle, in its forty-third flight (PSLV-C41) in XL configuration launched IRNSS-1I Satellite.
• The 'XL' configuration of PSLV is used for the twentieth time.
• The IRNSS-1I is the eighth satellite to join the NavIC navigation satellite constellation and was launched on April 12, 2018.
• PSLV-C43 lifted off on November 29, 2018 from the First Launch Pad (FLP) of Satish Dhawan Space Centre, Sriharikota and successfully launched India’s Hyper spectral Imaging Satellite (HysIS) and 30 international co-passenger satellites.

• India’s next generation high throughput communication satellite, GSAT-11 was successfully launched on December 05, 2018 from Kourou launch base, French Guiana by Ariane-5 VA-246.

• It is weighing about 5854 kg and GSAT-11 is the heaviest satellite built by ISRO.
• GSLV-F11 successfully launched GSAT-7A, ISRO’s 39^th communication satellite, on December 19, 2018 from Satish Dhawan Space Centre, Sriharikota.

• GSLV-F11 is the 13^th flight of India’s Geosynchronous Satellite Launch Vehicle (GSLV) and its 7^th flight with indigenous Cryogenic Upper Stage (CUS).
• GSLV – F11 is ISRO’s fourth generation launch vehicle with three stages.
• It is a geostationary satellite carrying communication transponders in Ku-band.
• The Satellite is built to provide communication capability to the users over the Indian region.
• India’s telecommunication satellite, GSAT-31 was successfully launched on February 06, 2019 from Kourou launch base, French Guiana by Ariane-5 VA-247.

• On March 27, 2019 India conducted Mission Shakti, an anti-satellite missile test, from the Dr. A P J Abdul Kalam Island launch complex.
• This was a technological mission carried out by DRDO indigenously.
• Microsat-R, the satellite attacked by the mission, is one of India’s existing redundant satellites in lower orbit.

• With this test, India joins an exclusive group of space faring nations consisting of USA, Russia and China.
• India’s PSLV-C46 successfully launched RISAT-2B satellite from Satish Dhawan Space Centre, Sriharikota on May 22, 2019.

• The satellite is intended to provide services to Agriculture, Forestry and Disaster Management domains.
• Geosynchronous Satellite Launch Vehicle, GSLV MkIII-M1 rocket, carrying Chandrayaan-2 spacecraft was launched from the Satish Dhawan Space Centre, Sriharikota on July 22, 2019.
• Chandrayaan-2 is India's second mission to the moon.
• It comprises a fully indigenous Orbiter, Lander (Vikram) and Rover (Pragyan).

• The Rover Pragyan is housed inside of the Vikram lander.
• Chandrayaan-2 has several science payloads to facilitate a more detailed understanding of the origin and evolution of the Moon.
• ISRO is set to launch first solar mission Aditya-L1 in 2019-2020 by Polar Satellite Launch Vehicle (PSLV-XL) from Sriharikota.
• It will be India’s first dedicated scientific mission to study sun.
• The mission aims to put 1,500-kg heavy class Aditya-L1 satellite into halo orbit around Lagrangian point L1, a point between Sun and Earth.

• Gaganyaan, India’s first Indian human mission will be launched by ISRO by 2022.
• Under the Gaganyaan, three flights will be sent in orbit.
• Of the three, there will be two unmanned flights and one human spaceflight.
• The human space flight programme, called the Orbital Module will have three Indian astronauts including one woman.
• The payload will consist of:
  • Crew module - carrying human beings.
  • Service module - powered by two liquid propellant engines.
• It will be equipped with emergency escape and emergency mission abort.
• GSLV Mk III, will be used to launch Gaganyaan as it has the necessary payload capability.
• This mission will make India fourth nation in the world after USA, Russia and China to launch human spaceflight mission.

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