Satellite. Solar system Essay Example for Free

Satellite. Solar system Essay A satellite is defined as any object that orbits any other object. Satellites can be celestial, such as a moon orbiting a planet in the solar system, or a planet in the solar system orbiting the sun. Satellites can also be man-made. Man-made satellites are typically launched into outer space from earth to collect data, photos and other information about Earth and all the many things that exist around it. An animation depicting the orbits of GPS satellites in medium earth orbit. A full size model of the Earth observation satellite ERS 2  In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavor. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon. The first artificial satellite, Sputnik 1, was launched by the Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth. These originate from more than 50 countries and have used the satellite launching capabilities of ten nations. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Venus, Mars, Jupiter and Saturn. Satellites are used for a large number of purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit. Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control and orbit control. HISTORY OF ARTIFICIAL SATELLITES Sputnik 1: The first artificial satellite The first artificial satellite was Sputnik 1, launched by the Soviet Union on October 4, 1957, and initiating the Soviet Sputnik program, with Sergei Korolev as chief designer. This in turn triggered the Space Race between the Soviet Union and the United States. Sputnik 1 helped to identify the density of high atmospheric layers through measurement of its orbital change and provided data on radio-signal distribution in the ionosphere. The unanticipated announcement of Sputnik 1s success precipitated the Sputnik crisis in the United States and ignited the so-called Space Race within the Cold War. Sputnik 2 was launched on November 3, 1957 and carried the first living passenger into orbit, a dog named Laika. TYPES OF SATELLITE ïÆ'ËœCommunication satellites †¢Communication satellites provide a worldwide linkup of radio, telephone, and television. †¢The first communication satellite was Echo 1, launched in 1960. †¢Relay 1 and telstar 1 were the first active communications satellites. †¢They were launched in 1962. ïÆ'ËœNavigation satellites †¢Navigation satellites are mainly intended to help aircraft, ships and nuclear submarines. †¢These satellites provide constant signals by which aircraft and ships can determine their positions with great accuracy. ïÆ'ËœWeather satellites †¢Weather satellites carry cameras and other instruments pointed toward Earths atmosphere. †¢They can provide advance warning of severe weather and are a great aid to weather forecasting. ïÆ'ËœMilitary satellites †¢ Many military satellites are similar to commercial ones, but they send encrypted data that only a special receiver can decipher. †¢ Military surveillance satellites take pictures just as other earth-imaging satellites do, but cameras on military satellites usually have a higher resolution. ïÆ'ËœScientific satellites †¢Earth-orbiting satellites can provide data to map Earth, determine the size and shape of Earth, and study the dynamics of the oceans and the atmosphere. †¢ Scientists also use satellites to observe the Sun, the Moon, other planets and their moons, comets, stars, and galaxies. HOW ARE SATELLITES LAUNCHED ïÆ'ËœThe trick when launching a satellite is to get it high enough to do its job without losing the capsule to outer space. ïÆ'Ëœ Its a delicate balance of push and pull, accomplished by the inertia of the moving object and the Earths gravity. GEOSYNCHRONOUS SATELLITE LAUNCH VEHICLE ïÆ'ËœThe Geosynchronous Satellite Launch Vehicle (usually known by its abbreviation, GSLV) is an expendable launch system operated by the Indian Space Research Organization (ISRO). ïÆ'ËœIt was developed to enable India to launch its INSAT-type satellites into geostationary orbit and to make India less dependent on foreign rockets. GSLV Geosynchronous Satellite Launch Vehicle FunctionMedium Lift Launch System ManufacturerISRO Country of origin India Size Height49 metres (161 ft) Diameter2.8 metres (9 ft 2 in) Mass402,000 kilograms (890,000 lb) Stages3 Capacity Payload to LEO 5,100 kilograms (11,000 lb) Payload to GTO 2,000 to 2,500 kilograms (4,400 to 5,500 lb) Launch history StatusActive Launch sitesSatish Dhawan Total launches6 (5 Mk.I, 1 Mk.II) Successes2 (Mk.I) Failures3 (2 Mk.I, 1 Mk.II) Partial failures1 (Mk.I) Maiden flightMk.I: 18 April 2001 Mk.II: 15 April 2010 Boosters (Stage 0) No boostersFour Engines1 L40H Vikas 2 Thrust680 kilonewtons (150,000 lbf) Total thrust2,720 kilonewtons (610,000 lbf) Specific impulse 262 sec Burn time160 seconds FuelN2O4/UDMH First Stage Engines1 S139 Thrust4,700 kilonewtons (1,100,000 lbf) Specific impulse 166 sec Burn time100 seconds FuelHTPB (solid) Second Stage Engines1 GS2 Vikas 4 Thrust720 kilonewtons (160,000 lbf) Specific impulse 295 s (2.89 kN†¢s/kg) Burn time150 seconds FuelN2O4/UDMH Third Stage (GSLV Mk.I) 12KRB Engines1 KVD-1 Thrust69 kilonewtons (16,000 lbf) Specific impulse 460 s (4.5 kN†¢s/kg) Burn time720 seconds FuelLOX/LH2 Third Stage (GSLV Mk.II) CUS12 Engines1 ICE Thrust73.5 kilonewtons (16,500 lbf) Specific impulse 460 s (4.5 kN†¢s/kg) Burn time720 seconds FuelLOX/LH2 LIQUID BOOSTERS One of the strap-ons of GSLV-F04 being brought to the Vehicle Assembly Building The GSLV uses four L40 liquid strap-on boosters derived from the L37.5 second stage, which are loaded with 40 tons of hypergolic propellants (UDMH N2O4). The propellants are stored in tandem in two independent tanks 2.1 m diameter. The engine is pump-fed and generates 680 kN (150,000 lbf) of thrust. First stage S139 stage is 2.8 m in diameter and is made of M250 grade maraging steel and it has a nominal propellant loading of 139 t. Second stage The second stage is powered by the Vikas engine. It has 2.8 m diameter and uses 37.5 metric tons of liquid propellants with UDMH as fuel and nitrogen tetroxide (N2O4) as oxidizer, in two aluminium alloy compartments separated by a common bulk head. It delivers 720 kN (160,000 lbf) of thrust. Third stage GSLV Mk.II D3 The third stage is propelled by a cryogenic rocket engine, 2.8 m in diameter and uses liquid hydrogen (LH2) and liquid oxygen (LOX) in two separate tanks of aluminium alloy interconnected by an inter-stage. Propellant loading is 12.5 t. The indigenous cryogenic engine was built in Tamil Nadu at the Liquid Propulsion Systems Centre. POLAR SATELLITE LAUNCH VEHICLE ïÆ'ËœThe Polar Satellite Launch Vehicle commonly known by its abbreviation PSLV is an expendable launch system developed and operated by the Indian Space Research Organization (ISRO). ïÆ'ËœIt was developed to allow India to launch its Indian Remote Sensing (IRS) satellites into sun synchronous orbits. ïÆ'ËœPSLV can also launch small size satellites into geostationary transfer orbit (GTO). ïÆ'ËœThe PSLV has launched 41 satellites (19 Indian and 22 from other countries) into a variety of orbits till date. Polar Satellite Launch Vehicle PSLV-C8 (CA Variant) carrying the AGILE x-ray and ÃŽ ³-ray astronomical satellite of the ASI lifting off from Sriharikota FunctionMedium Lift Launch System ManufacturerISRO Country of origin India Size Height44 metres (144 ft) Diameter2.8 metres (9 ft 2 in) Mass294,000 kilograms (650,000 lb) Stages4 Capacity Payload to LEO 3,250 kilograms (7,200 lb) Payload to HCO 1,600 kilograms (3,500 lb)[1] Payload to GTO 1,060 kilograms (2,300 lb)[1] Launch history StatusActive Launch sitesSriharikota Total launches17 PSLV: 10 PSLV-CA: 6 PSLV-XL: 1 Successes15 PSLV: 8 PSLV-CA: 6 PSLV-XL: 1 Failures1 (PSLV) Partial failures1 (PSLV) Maiden flightPSLV: 20 September 1993 PSLV-CA: 23 April 2007 PSLV-XL: 22 October 2008 Notable payloadsChandrayaan-1 Boosters (Stage 0) â„â€" boosters6 Engines1 solid Thrust502.600 kN Specific impulse 262 sec Burn time44 seconds FuelHTPB (solid) First stage Engines1 solid Thrust4,860 kN Specific impulse 269 sec Burn time105 seconds FuelHTPB (solid) Second stage Engines1 Vikas Thrust725 kN Specific impulse 293 sec Burn time158 seconds FuelN2O4/UDMH Third stage Engines1 solid Thrust328 kN Specific impulse 294 sec Burn time83 seconds FuelSolid Fourth stage Engines2 liquid Thrust14 kN Specific impulse 308 sec Burn time425 seconds FuelMMH/UDMH PSLV is designed and developed at Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram and Kerala. The inertial systems are developed by ISRO Inertial Systems Unit (IISU) at Thiruvananthapuram. The liquid propulsion stages for the second and fourth stages of PSLV as well as the reaction control systems are developed by the Liquid Propulsion Systems Centre (LPSC), also at Thiruvananthapuram. The solid propellant motors are processed by Satish Dhawan Space Centre SHAR, which also carries out launch operations. After some delays, the PSLV had its first launch on 20 September 1993. Although all main engines performed as expected, an altitude control problem was reported in the second and third stages. After this initial setback, ISRO met complete success with the third developmental launch in 1996. Further successful launches followed in 1997, 1999, and 2001. PSLV continues to be the work horse of Indian satellite launches, especially for LEO satellites and the Chandrayaan Projects. It has undergone several improvements with each subsequent version, especially those involving thrust, efficiency as well as weight. ORBIT ïÆ'ËœAn orbit is a regular, repeating path that an object in space takes around another one. ïÆ'ËœAn object in an orbit is called a satellite. A satellite can be natural, like the moon, or human -made. ïÆ'ËœIn our solar system, the Earth orbits the Sun, as do the other eight planets. ïÆ'ËœThey all travel on or near the orbital plane, an imaginary disk-shaped surface in space. ïÆ'Ëœ All of the orbits are circular or elliptical in their shape. In addition to the planets orbits. HOW A SATELLITE STAY IN THE ORBIT ïÆ'ËœThe forward motion of the satellite is its momentum. If the gravity of the earth is not acting on the satellite, the satellite would continue in one direction. ïÆ'ËœThe swinging of the satellite gives it its forward motion. ïÆ'Ëœ When these two forces are equal, the satellite remains in orbit, without falling into or flying away from the Earth. ïÆ'Ëœ A satellites forward motion is controlled by rockets. ïÆ'ËœWhen the rockets are not fired, inertia keeps the satellite going in one direction. HOW SATELLITES WORK ïÆ'ËœReceiving uplinked radio signals from earth satellite transmission stations (antennas). ïÆ'ËœAmplifying received radio signals ïÆ'ËœSorting the input signals and directing the output signals through input/output signal multiplexers to the proper downlink antennas for retransmission to earth satellite receiving stations (antennas). MERITS ïÆ'ËœIn communication. ïÆ'ËœFor military purposes. ïÆ'ËœFor weather broadcasting. ïÆ'ËœIn terrestrial application. ïÆ'ËœSatellite Services. †¢Satellite internet access †¢Satellite phone †¢Satellite radio †¢Satellite television †¢Satellite navigation DE-MERITS ïÆ'ËœLifetime of a satellite is limited. ïÆ'ËœOnce damaged it is difficult to repair. ïÆ'ËœEconomically costly. ïÆ'ËœA small damage in any part can destroy the whole satellite. CONCLUSION ïÆ'ËœNow a day’s satellite is a basic communication media. ïÆ'ËœAny information can be transmitting from one point to another with the help of satellite. ïÆ'ËœAll people are using satellites directly or indirectly. ïÆ'ËœWithout satellites the days cannot be imagined.