Context:
The launch of earth observation satellite EOS-03, aboard the Indian Space Research Organisation ’s (Isro) heavy launch vehicle GSLV-F10 was unsuccessful as the third stage of the engine did not ignite.
The performance of the first and second stages was normal. However, the Cryogenic Upper Stage ignition did not happen due to technical anomaly.
Relevance:
GS-III: Science and Technology (Space Technology, Advancements in Space technology), Prelims
Dimensions of the Article:
- About Geosynchronous Satellite Launch Vehicle (GSLV)
- About GSLV launch vehicles
- About GSLV and PSLV – Differences and Similarities
- About Propellants used in our Rockets
- What is a Geostationary Orbit, and what the other types of Orbits?
About Geosynchronous Satellite Launch Vehicle (GSLV)
- Geosynchronous Satellite Launch Vehicle (GSLV) is an expendable launch system operated by the Indian Space Research Organisation (ISRO).
- GSLV was used in fourteen launches from 2001 to 2021, with more launches planned.
- The Geosynchronous Satellite Launch Vehicle (GSLV) project was initiated in 1990 with the objective of acquiring an Indian launch capability for geosynchronous satellites.
- GSLV uses major components that are already proven in the Polar Satellite Launch Vehicle (PSLV) launch vehicles in the form of solid rocket boosters and the liquid-fueled Vikas engine.
- Due to the thrust required for injecting the satellite in a geostationary transfer orbit (GTO) the third stage was to be powered by a LOX/LH2 Cryogenic engine – and the Indian cryogenic engine which was built for this purpose at the Liquid Propulsion Systems Centre uses liquid hydrogen (LH2) and liquid oxygen (LOX).
About GSLV launch vehicles
- GSLV Mark III is a three-stage medium-lift launch vehicle developed by the Indian Space Research Organisation (ISRO).
- GSLV MK III is designed to carry the 4-ton weight of satellites into Geosynchronous Transfer Orbit (GTO), or about 10 tons to Low Earth Orbit (LEO), which is about twice the capacity of GSLV Mk II, and more than thrice the capacity of ISRO’s old workhorse PSLV.
- The GSLV-F10 was a three-stage engine rocket, with
- the first being solid fuel and the four strap-on motors by liquid fuel;
- the second being liquid fuel engine;
- the and third being a cryogenic engine.
About Acquiring the Cryogenic Engine
ISRO, during the 1990s, planned to acquire booster technology from the Russian Space Organization, Glavkosmos. But, since the United States opposed this technology transfer and imposed sections against the ISRO in 1992, Glavkosmos halted the transfer but agreed to sell some hardware. As a result, India developed its own technology and research capability.
About GSLV and PSLV – Differences and Similarities
- GSLV (Geosynchronous Satellite Launch Vehicle) and PSLV (Polar satellite launch vehicle) both are satellite- launch vehicles (rockets) developed by ISRO.
- India joined a group of six nations on 1994, and successfully demonstrated the placement of 800- kg remote sensing satellite, IRS-P2 using PSLV.
- PSLV earned its title ‘the Workhorse of ISRO’ when it consistently delivered the IRS series of satellites.
- GSLV presented the Indian Space Program with its most demanding test. It was developed when India felt the need for a heavy lift booster, in the early 1980s (as PSLV was inadequate to place heavy payloads in geosynchronous orbit).
- PSLV is the third generation launch vehicle of India and the first Indian launch vehicle which is equipped with liquid stages. GSLV, on the other hand, is the fourth generation launch vehicle and is a three-stage vehicle with four liquid strap-ons.
- PSLV is designed mainly to deliver the earth observation or remote sensing satellites, whereas, GSLV has been designed for launching communication satellites. GSLV delivers satellites into a higher elliptical orbit, Geosynchronous Transfer Orbit (GTO) and Geosynchronous Earth Orbit (GEO).
- PSLV can carry satellites up to a total weight of 2000 kgs into space and reach up to an altitude of 600-900 km. GSLV can carry weight up to 5000 kgs and reach up to 36,000 km.
About Propellants used in our Rockets
- A propellant is a chemical mixture burned to produce thrust in rockets and consists of a fuel and an oxidizer.
- Fuel is a substance that burns when combined with oxygen-producing gas for propulsion.
- An oxidizer is an agent that releases oxygen for combination with a fuel. The ratio of oxidizer to fuel is called the mixture ratio.
- Propellants are classified according to their state – liquid, solid, or hybrid.
- Liquid Propellants: In a liquid propellant rocket, the fuel and oxidizer are stored in separate tanks and are fed through a system of pipes, valves, and turbopumps to a combustion chamber where they are combined and burned to produce thrust.
- Liquid propellants used in rockets can be classified into three types: petroleum, cryogens, and hypergolic.
- Cryogenic propellants are liquefied gases stored at very low temperatures, most frequently liquid hydrogen (LH2) as the fuel and liquid oxygen (LO2 or LOX) as the oxidizer. Hydrogen remains liquid at temperatures of -253 oC (-423 oF) and oxygen remains in a liquid state at temperatures of -183 oC (-297 oF).
- Solid propellant: These are the simplest of all rocket designs. They consist of a casing, usually steel, filled with a mixture of solid compounds (fuel and oxidizer) that burn at a rapid rate, expelling hot gases from a nozzle to produce thrust. When ignited, a solid propellant burns from the center out towards the sides of the casing.
What is a Geostationary Orbit, and what the other types of Orbits?
Geostationary orbit
- A geostationary orbit, often referred to as a GEO orbit, circles the Earth above the equator from west to east at a height of 36 000 km. As it follows the Earth’s rotation, which takes 23 hours 56 minutes and 4 seconds, satellites in a GEO orbit appear to be ‘stationary’ over a fixed position. Their speed is about 3 km per second.
- As satellites in geostationary orbit continuously cover a large portion of the Earth, this makes it an ideal orbit for telecommunications or for monitoring continent-wide weather patterns and environmental conditions. It also decreases costs as ground stations do not need to track the satellite. A constellation of three equally spaced satellites can provide full coverage of the Earth, except for the polar regions.
Geostationary transfer orbit
- This is an elliptical Earth orbit used to transfer a spacecraft from a low altitude orbit or flight trajectory to geostationary orbit. The apogee is at 36,000 km. When a spacecraft reaches this point, its apogee kick motor is fired to inject it into geostationary orbit.
Low Earth orbits
- A low Earth orbit is normally at an altitude of less than 1000 km and could be as low as 160 km above the Earth. Satellites in this circular orbit travel at a speed of around 7.8 km per second. At this speed, a satellite takes approximately 90 minutes to circle the Earth.
- In general, these orbits are used for remote sensing, military purposes and for human spaceflight as they offer close proximity to the Earth’s surface for imaging and the short orbital periods allow for rapid revisits. The International Space Station is in low Earth orbit.
Medium low Earth orbit
- This orbit takes place at an altitude of around 1000 km and is particularly suited for constellations of satellites mainly used for telecommunications. A satellite in this orbit travels at approximately 7.3 km per second.
Polar orbits
- As the name suggests, polar orbits pass over the Earth’s polar regions from north to south. The orbital track of the satellite does not have to cross the poles exactly for an orbit to be called polar, an orbit which passes within 20 to 30 degrees of the poles is still classed as a polar orbit.
- These orbits mainly take place at low altitudes of between 200 to 1000 km. Satellites in polar orbit look down on the Earth’s entire surface and can pass over the North and South Poles several times a day.
- Polar orbits are used for reconnaissance and Earth observation. If a satellite is in polar orbit at an altitude of 800 km, it will be travelling at a speed of approximately 7.5 km per second.
Sun synchronous orbits
- These are polar orbits which are synchronous with the Sun. A satellite in a sun synchronous orbit would usually be at an altitude of between 600 to 800 km. Generally, these orbits are used for Earth observation, solar study, weather forecasting and reconnaissance, as ground observation is improved if the surface is always illuminated by the Sun at the same angle when viewed from the satellite.
Click Here to read more about Earth Observation Satellites EOS-03
-Source: Indian Express
