SATELLITE LAUNCHERA PPT BY SAATWIK SUMAN.

CONTENTS• INTRODUCTION• ORIGIN• TYPES• HOW A LAUNCH VEHICLE WORKS?• FUEL• IDEAL LAUNCH BASES• INDIA’S SLVS AT A GLANCE

LAUNCH VEHICLE • Launch vehicle or carrier rocket or satellite

launcher is a rocket-powered vehicle used to transport a spacecraft or a payload beyond Earth’s atmosphere, either into orbit around Earth or to some other destination in outer space. . A launch system includes the launch vehicle, the launch pad, and other infrastructure Practical launch vehicles have been used to send manned spacecraft, unmanned space probes, and satellites into space since the 1950s. They include the Soyuz and Proton launchers of Russia as well as several converted military missiles; Russia is developing a new family of launchers called Angara. Europe operates the Ariane V and Vega launchers. Current U.S. launch vehicles include the Atlas, Delta, Falcon, and Antares expendable boosters.

ORIGIN• Most space launch vehicles trace their heritage

to ballistic missiles developed for military use during the 1950s and early ’60s. Those missiles in turn were based on the ideas first developed by Konstantin Tsiolkovsky in Russia, Robert Goddard in the United States, and Hermann Oberth in Germany. Each of these pioneers of space exploration recognized the centrality of developing successful launch vehicles if humanity were to gain access to outer space.

• Tsiolkovsky late in the 19th century was the first to recognize the need for rockets to be constructed with separate stages .Goddard was the first to build experimental liquid-fueled rockets; his first rocket, launched in Auburn, Massachusetts, on March 16, 1926, rose 12.5 metres and traveled 56 metres from its launching place.

Robert H. Goddard and a liquid oxygen–gasoline rocket in its frame; the rocket was first fired on

March 16, 1926, at Auburn, Mass.

TYPES• Expendable launch vehicles are designed for one-time use. They usually

separate from their payload and disintegrate during atmospheric reentry.• In contrast, reusable launch vehicles are designed to be recovered intact and

launched again. The Space Shuttle was a launch vehicle with components used for multiple orbital spaceflights.

• Launch vehicles are often classified by the amount of mass they can carry into orbit. For example, a Proton rocket can lift 22,000 kilograms into low Earth orbit (LEO). Launch vehicles are also characterized by their number of stages. Rockets with as many as five stages have been successfully launched, and there have been designs for several single-stage-to-orbit vehicles. Additionally, launch vehicles are very often supplied with boosters supplying high early thrust, normally burning with other engines. Boosters allow the remaining engines to be smaller, reducing the burnout mass of later stages to allow larger payloads.

• Other frequently-reported characteristics of launch vehicles are the launching nation or space agency and the company or consortium manufacturing and launching the vehicle.

EXPENDABLE LAUNCH VEHICLE

REUSABLE LAUNCH VEHICLE

”

“ For every action, there is an equal

and opposite reaction.A launch vehicle is a good illustration of Newton’s third law of motion.

How a launch vehicle works?

HOW A LAUNCH VEHICLE WORKS?• A launch vehicle is a good illustration

of Newton’s third law of motion, “For every action, there is an equal and opposite reaction.” In the case of a launch vehicle, the “action” is the flow out the rear of the vehicle of exhaust gases produced by the combustion of the vehicle’s fuel in its rocket engine, and the “reaction” is the pressure, called thrust, applied to the internal structure of the launch vehicle that pushes it in the direction opposite to the exhaust flow. Unlike jet engines, which operate on the same action-reaction principle but obtain the oxygen needed for burning their fuel from the atmosphere, rockets carry with them their own oxidizing agent. In that way, they can operate in the vacuum beyond the atmosphere.

HOW A LAUNCH VEHICLE WORKS?

• The primary goal of launch vehicle designers is to maximize the vehicle’s weight-lifting capability while at the same time providing an adequate level of reliability at an acceptable cost. Achieving a balance among these three factors is challenging. In order for the launch vehicle to lift off of Earth, its upward thrust must be greater than the combined weight of its spacecraft payload, the vehicle’s propellants, and its structure. This puts a premium on making the vehicle’s mechanical structure, fuel tanks, and rocket engines as light as possible but strong enough to withstand the forces and stresses associated with rapid acceleration through a resistant atmosphere. Most often, propellant makes up 80 percent or more of the total weight of a launch vehicle–spacecraft combination prior to launch.

FUEL• The fuel used to power rockets can be divided

into two broad categories: liquid and solid.

• Liquid fuels can range from a widely available substance such as ordinary kerosene, which can be used at ground temperature, to liquid hydrogen, which must be maintained at the extremely low temperature of 20 °K .In order to burn, liquid rocket fuel must be mixed in the combustion chamber of a rocket engine with an oxygen-rich substance, called an oxidizer. The oxidizer usually used with both kerosene and liquid hydrogen is liquid oxygen. Oxygen must be kept at a temperature less than −183 °C in order to remain in a liquid state. The oxidizer used with hypergolic fuel is usually nitrogen tetroxide or nitric acid.

• Liquid-fuel rocket engines are complex machines. In order to reach maximum efficiency, both fuel and oxidizer must be pumped into the engine’s combustion chamber at high rates, under high pressure, and in suitable mixtures. 

FUEL• Solid-propellant rocket motors are simple in

design, in many ways resembling large fireworks. They consist of a casing filled with a rubbery mixture of solid compounds (both fuel and oxidizer) that burn at a rapid rate after ignition. The fuel is usually some organic material or powdered aluminum; the oxidizer is most often ammonium perchlorate. These are mixed together and are cured with a binder to form the rocket propellant. Solid rocket motors are most often used as strap-ones to the liquid-fueled first stage of a launch vehicle to provide additional thrust during liftoff and the first few minutes of flight The exhaust from the burning of the fuel emerges through a nozzle at the bottom of the rocket casing, and that nozzle shapes and accelerates the exhaust to provide the reactive forward thrust.

ROCKET MOTOR

INCREASING LAUNCH SUCCESS YEAR BY YEAR

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IDEAL LAUNCH BASES

• Most launch vehicles take off from sites on land, although a few are air- or sea-launched. To function as a launch base, a particular location has to have facilities for assembling the launch vehicle, handling its fuel, preparing a spacecraft for launch, mating the spacecraft and launch vehicle, and checking them out for launch readiness. In addition, it must have launch pads and the capability to monitor the launch after liftoff and ensure safety in the launch range. This usually requires a significant amount of land located away from heavily populated areas but with good air, sea, rail, or land access for transport of various components. Other desirable characteristics include a location that allows the early stages of launch, when first stages are separated and most launch accidents happen, to take place over water or sparsely populated land areas.

IDEAL LAUNCH BASES

• Another desirable characteristic is a location as near as possible to the Equator. Many launches take place in an eastward direction to take advantage of the velocity imparted by the rotation of Earth in that direction. This velocity is greatest at the Equator and decreases with increased latitude. For example, the additional velocity provided by Earth’s rotation is 463 metres per second at the European launch base in French Guiana, which is located very close to the Equator at latitude 5.2° N. Whereas it is only 328 metres per second at the Russian Baikonur Cosmodrome in Kazakhstan, which is located at latitude 46° N. Earth’s naturally imparted velocity, though small in comparison with the velocity provided by the rocket engines, lessens the demands on the launch vehicle.

INDIA’S SLVS AT A GLANCE

SLV• The Satellite Launch

Vehicle  SLV was a project started in the early 1970s by the Indian Space Research Organization to develop the technology needed to launch satellites. The project was headed by APJ Abdul Kalam. SLV was intended to reach a height of 400 km and carry a payload of 40 kg. The first experimental flight of SLV-3, in August 1979, was only partially successful.

• It was a four-stage rocket with all solid-propellant motors.

• The first launch of the SLV took place in Sriharikota on 10 August 1979. The fourth and final launch of the SLV took place on 17 April 1983.

ASLV

• The Augmented Satellite Launch Vehicle or Advanced Satellite Launch Vehicle', also known as ASLV, was a five-stage solid-fuel rocket developed by the Indian Space Research Organization (ISRO) to place 150 kg satellites into LEO. This project was started by India during the early 1980s to develop technologies needed for a payload to be placed into a geostationary orbit. Its design was based on Satellite Launch Vehicle. ISRO did not have sufficient funds for both the Polar Satellite Launch Vehicle programme and the ASLV programme at the same time and the ASLV programme was terminated after the initial developmental flights. The payloads of ASLV were Stretched Rohini Satellites.

PSLV• The 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). It was developed to allow India to launch its Indian Remote Sensing (IRS) satellites into Sun-synchronous orbits, a service that was, until the advent of the PSLV, commercially available only from Russia. PSLV can also launch small size satellites into geostationary transfer orbit(GTO).

• IN THE YEAR 2015 ALONE INDIA SUCCESSFULLY LAUNCHED 17 FOREIGN SATELLITES BELONGING TO CANADA, INDONESIA, SINGAPORE, THE UNITED KINGDOM AND THE UNITED STATES. SOME NOTABLE PAYLOADS LAUNCHED BY PSLV INCLUDE INDIA'S FIRST LUNAR PROBECHANDRAYAAN-1, INDIA'S FIRST INTERPLANETARY MISSION MANGALYAAN (MARS ORBITER) AND INDIA'S FIRST SPACE OBSERVATORY , ASTROSAT .

GSLV

• Geosynchronous Satellite Launch Vehicle abbreviated in English as GSLV, is an expendable launch system operated by the Indian Space Research Organization (ISRO). It was developed to enable India to launch its satellites without dependence on foreign rockets and providers. GSLV has been used in nine launches to date, since its first launch in 2001 through to its most recent launch on August 27, 2015 of the GSAT-6.

GSLV MARK 3

• The Geosynchronous Satellite Launch Vehicle Mark III  also called LVM3 or GSLV-III) is a launch vehicle developed by the Indian Space Research Organization (ISRO).

• It is intended to launch satellites into geostationary orbit and as a launcher for an Indian crew vehicle. The GSLV-III features an Indian cryogenic third stage and a higher payload capacity than the current GSLV.

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