ASSIGNMENT

NAME: ANUPRIYA.K

CLASS: 1 B.SC(IT)

SATELLITEAPPLICATIONS TECHNOLOGY :The Applications Technology Satellites were a series of experimental satellites launched by NASA. The program was launched in 1966 to test the feasibility of placing a satellite into geosynchronous orbit.[1] The satellites were primarily designed to act as communication satellites, but also carried equipment related to meteorology and navigation. ATS-6 was the world's first educational satellite as well as world's first experimental Direct Broadcast Satellite as part of the Satellite Instructional Television Experiment between NASA and ISRO. satellite, artificial, object constructed by humans and placed in orbit around the earth or other celestial body (see also space probe). The satellite is lifted from the earth's surface by a rocket and, once placed in orbit, maintains its motion without further rocket propulsion. The first artificial satellite, Sputnik I, was launched on Oct. 4, 1957, by the USSR; a test payload of a radio beacon and a thermometer demonstrated the feasibility of orbiting a satellite. The first U.S. satellite, Explorer I, launched on Jan. 31, 1958, returned data that was instrumental in the discovery of the Van Allen radiation belts. During the first decade of space exploration, all of the satellites were launched from either the United States or USSR. Today, there are more than three dozen launch sites in use or under construction in more than a dozen countries.

Satellite types :

Satellites can be classified by their functions. Satellites are launched into space to do a specific job. The type of satellite that is launched to monitor cloud patterns for a weather station will be different than a satellite launched to send television signals across Canada. The satellite must be designed specifically to fulfill its function.

Below are the names of nine different types of satellites.

Astronomy satellites - Hubble Space Telescope

Atmospheric Studies satellites - Polar

Communications satellites - Anik E

Navigation satellites - Navstar

Reconaissance satellites - Kennan, Big Bird, Lacrosse

Remote Sensing satellites - Radarsat

Search and Rescue satellites - Cospas-Sarsat

Space Exploration satellites GalileoAdvantages of Satellites

In today's world of wireless communications, high definition television and global access to the Internet, many people are unclear about the inherent advantages of satellite communications.

Why does the satellite industry continue to grow? When is satellite the best solution? Here is a quick look at some key advantages of satellite communications:

Cost Effectiveness - Cost of satellite capacity does not increase with the number of users/receive sites, or with the distance between communication points. Whether crossing continents or staying local, satellite connection cost is distance insensitive.

Global Availability - Communications satellites cover all land masses and there is growing capacity to serve maritime and even aeronautical markets. Customers in rural and remote regions around the world who cannot obtaio high speed Internet access from a terrestrial provider are increasingly relying on satellite communications.

Superior Reliability - Satellite communications can operate independently from terrestrial infrastructure. When terrestrial outages occur from man-made and natural events, satellite connections remain operational.

Superior Performance - Satellite is unmatched for broadcast applications like television. For two-way IP networks, the speed, uniformity and end-to-end control of today's advanced satellite solutions are resulting in greater use of satellite by corporations, governments and consumers.

Immediacy and Scalability - Additional receive sites, or nodes on a network, can readily be added, sometimes within hours. All it takes is ground-based equipment. Satellite has proven its value as a provider of "instant infrastructure" for commercial, government and emergency relief communications.

Versatility and More - Satellites effectively support on a global basis all forms of communications ranging from simple point-of-sale validation to bandwidth intensive multimedia applications. Satellite solutions are highly flexible and can operate independently or as part of a larger network.

between NASA and ISRO.

Advantages & Disadvantages

Advantages:

Flexible (if transparent transponders)

Easy to install new circuits

Circuit costs independent of distance

Broadcast possibilities

Temporary applications (restoration)

Niche applications

Mobile applications (especially "fill-in")

Terrestrial network "by-pass"

Provision of service to remote or underdeveloped areas

User has control over own network

1-for-N multipoint standby possibilities

Disadvantages

Large up front capital costs (space segment and launch)

Terrestrial break even distance expanding (now approx. size of Europe)

Interference and propagation

Congestion of frequencies and orbit

Satellite Instructional Television Experiment

An ISRO technical an next to a working model of the solid-state television set, designed with NASA assistance, for use in SITE. Image courtesy NASA

The Satellite Instructional Television Experiment or SITE was an experimental satellite communications project launched in India in 1975, designed jointly by NASA and the Indian Space Research Organization (ISRO). The project made available informational television programmes to rural India. The main objectives of the experiment were to educate the poor people of India on various issues via satellite broadcasting, and also to help India gain technical experience in the field of satellite communications.

The experiment ran for one year from 1 August 1975 to 31 July 1976, covering more than 2400 villages in 20 districts of six Indian states and territories. (Andhra Pradesh, Bihar, Karnataka, Madhya Pradesh, Orissa, Rajasthan) The television programmes were produced by All India Radio and broadcast by NASA's ATS-6 satellite stationed above India for the duration of the project. The project was supported by various international agencies such as the UNDP, UNESCO, UNICEF and ITU. The experiment was successful, as it played a major role in helping develop India's own satellite program, INSAT.[1] The project showed that India could use advanced technology to fulfill the socio-economic needs of the country. SITE was followed by similar experiments in various countries, which showed the important role satellite TV could play in providing education.