Essays

For the purpose of putting Indian satellites in space, the Governments established a Space Science & Technology Centre (SSTC) in 1965 in Thumba, followed by the erection of a Satellite Telecommunication Earth Station in 1967 at Ahmadabad. Since the creation of the Indian Space Research Organisation (ISRO) on August 15, 1969, in the Department of Atomic Energy, ISRO has managed India's space research and the uses of space for peaceful purposes.

In 1972, the Government established the Space Commission and the Department of Space (DOS) to conduct the nation's space activities for ISRO at four space centers across the country. DOS reports directly to the Prime Minister and ISRO was placed under DOS on June 1, 1972, and made a Government organisation on April 1, 1975.

The first Indian satellite to be put in space was Aryabhata, which dates back to April 19, 1975. It was followed by the launch of Bhaskara- I, an Earth observation satellite, on June 7, 1979. While these two satellites were launched form sites outside India, India launched its own satellite for the first time on July 18, 1980. It was the Rohini-1 satellite carried aloft on a Satellite Launch Vehicle (SLV) rocket from the Sriharikota Island launch site. Since then, India has invested a great deal of its space development work in complex applications satellites.

India's two main interests are satellites for remote sensing and communications. These are used for weather pictures, disaster warnings and feeds to 552 television and 164 radio stations on the ground. By the end of 1985, the Rohini-3 communications satellite launched in August 1983 had extended nationwide television coverage from 20 percent to 70 percent of the population. Today it is about 90 percent.

One of the satellites in India's Stretched Rohini Satellite Series, SROSS-C, was launched on an Augmented Satellite Launch Vehicle (ASLV) on May 20, 1992. It was India's first astrophysics observatory. The 235-lb. satellite had a gamma ray burst detector composed of high voltage scintillation detectors focused on the southern sky. Unfortunately, the satellite fell from orbit after only 55 days. Its replacement, SROSS- . C2 was launched on May 4, 1994.

One of India's Geosynchronous Satellite Launch Vehicle (GSLV) rockets blasted off on April 18, 2001, from the Sriharikota Island launch site placed a 1.5-ton experimental communications satellite called GSAT-1 into geosynchronous orbit 22,300 miles above Earth. GSAT- 1 was a communications satellite with digital audio, data and video broadcasting using two S-bands, one high power C-band and two indigenous C-band transponders.

On October 22, 2001 India launched its Technology Experiment  Satellite (TES) aboard a Polar Satellite Launch Vehicle (PSLV-C3) from Sriharikota to a 350-mi.-high orbit. The 2,440-lb. satellite carried a panchromatic camera for Earth-imaging and tested new payload technologies, ranging from communications to remote sensing. The satellite was monitored by ISRO's Spacecraft Control Centre (SCC) Telemetry Tracking and Command Network (ISTRAC) at Bangalore along with its small network of tracking stations at Lucknow, Mauritius, and Bearslake, Russia.

The Indian National Satellite, INSAT-3C, designed and built by the ISRO was launched on a European Space Agency Ariane-4 rocket on January 24, 2002. The satellite added much communications capacity to the INSAT fleet in orbit, including 24 C-band transponders, six extended C-band transponders, two S-band broadcast satellite service transponders and mobile satellite service transponders. The satellite beams commercial television signals to customers in India. Subsequently. An Ariane 5 rocket carried the Indian-built satellite INSAT-3A to space from Kourou on April 9, 2003. The 3,000-lb. satellite carried a communications, weather imaging, and seareh-and-rescue payload. It measured about 9 by 6.5 by 6 ft., white its solar panels spanned about 43 ft.

RESOURCESAT-1, launched on October 17, 2003, was the tenth  satellite of ISRO in IRS series. It was intended to not only continue the remote sensing data services provided by IRS-1C and IRS-1D, both of which have far outlived their designed mission lives, but also to vastly enhance the data quality. Its mission life was five years.

GSAT-3, well known as EDUSAT was launched on September 20, 2004. As the first dedicated Educational Satellite, it provided the country with satellite based two way communications to class room for delivering educational materials. This Gee-synchronous satellite was developed on I-2K bus and was co-located with METSAT and INSAT-3C at 74 degree East longitude.

CARTOSAT-1, the first India Remote Sensing Satellite capable of providing in-orbit stereo images, was launched on May 5, 2005. The images are used for Cartographic applications meeting the global requirements. Cameras of this satellite have a resolution of 2.5m and can even distinguish a small car. The satellite provides stereo pairs required for generating Digital Elevation Models, Ortho Image products, and Value added products for various applications of Geographical Information System (GIS).

INSAT-4A, the first in INSAT-4 Satellites series provides services in Ku and C-band frequency bands- The Ku transponders cover the Indian main land while C-band transponders cover an extended area. This spacecraft was placed at 83 deg Eat along with INSAT-2E and INSAT-3B, by Ariane launch vehicle (ARIANE-5V 169) on December 22, 2005. The life of this satellite is estimated to be twelve years.

ISRO conducted a Space Capsule Recovery Experiment (SRE-1) to demonstrate the technology of an orbiting platform for performing experiments in microgravity conditions- SRE-1 mission provided a valuable experience in fields like navigation, guidance and control during the re-entry phase, hypersonic aero thermodynamic, development of reusable thermal protection system (TPS), recovery through deceleration and flotation, besides acquisition of basic technology for reusable launch vehicles. It was launched into a 635 km polar SSO in January 2007 as a co-passenger with CARTOSAT-2 and stayed in orbit for 10 days during which its payloads performed the operations. After completion of the experiments, the SRE capsule was de-boosted and recovered successfully kick on earth on 22nd January 2007,

INSAT-4B Spacecraft, the second in the INSAT-4 series of spacecrafts, configured with exclusive communication payloads to provide services in Ku and C frequency bands was co-located with INSAT-3A at 93.5 deg East longitude on March 12. 2007. The satellite has a life span of twelve years.

CARTOSAT-2A, the thirteenth satellite in the IRS series, was launched on April 28, 2008 with a mission life of five years. It is a sophisticated and rugged remote sensing satellite that can provide scene specific spot imagery. This satellite carries a panchromatic Camera (PAN) with a spatial resolution that is better than I m and swath of 9.6 km. Imageries from this satellite are used for cartographic applications like mapping, urban and rural infrastructure development and management, as well as application in Land Information (LIS) and GIS.

Oceansat-2 satellite, which derives its heritage from previous IRS missions, was launched by PSLV-C14 from Satish Dhawan Space Centre, Sriharikota on Sept- 23, 2009. It carried three payloads Ocean Colour Monitor (OCM), Ku-band Pencil Beam scatterometer (SCA'I') developed by ISRO, and Radio Occultation Sounder for Atmosphere (ROSA) developed by the Italian Space Agency. The satellite with a life of five years is envisaged to provide continuity of operational services of Oceansat-l(IRS-P4) with enhanced application potential.

Along with Oceansat-2, two more satellites—RISAT-2 and ANUSAT were also launched. RISAT-2 is a Radar Imaging Satellite with all weather capability to lake images of the earth. This Satellite will enhance ISRO's capability for Disaster Management applications. ANUSAT (Anna University Satellite) is the first satellite built by an Indian University under the over all guidance of ISRO and will demonstrate the technologies related to message store and forward operations.