Science & Technology
ISRO’s Launch Vehicles
- 19 Feb 2022
- 7 min read
For Prelims: Launch Vehicles, Satellites.
For Mains: Space Technology.
Why in News?
Recently, the Indian Space Research Organization (ISRO) launched an Earth Observation Satellite (EOS-04) along with two other smaller satellites into space using a PSLV (Polar Satellite Launch Vehicle) rocket. This was the 54th flight of the PSLV rocket.
What are Launch Vehicles and Satellites?
- The rockets have powerful propulsion systems that generate the huge amount of energy required to lift heavy objects like satellites into space, overcoming the gravitational pull of the earth.
- Satellites carry one or more instruments that do the scientific work for which they are sent into space. Their operational life sometimes extends up to decades.
- But rockets, or launch vehicles, become useless after the launch. Rockets’ only job is to take the satellites to their intended orbits.
- Rockets have several detachable energy-providing parts.
- They burn different kinds of fuels to power the rocket. Once their fuel is exhausted, they detach from the rocket and fall off, often burning off in the atmosphere due to air-friction, and getting destroyed.
- Only a small part of the original rocket goes till the intended destination of the satellite. Once the satellite is finally ejected, this last part of the rocket either becomes part of space debris, or once again burns off after falling into the atmosphere.
What are the Types of Launch Vehicles?
- For Lower Earth Orbits:
- Several satellites need to be deposited only in the lower earth orbits, which starts from about 180 km from earth’s surface and extends up to 2,000 km.
- Most of the earth-observation satellites, communication satellites, and even the International Space Station, a full-fledged laboratory in space that hosts astronauts, function in this space.
- It takes a smaller amount of energy to take the satellites to low-earth orbits, and accordingly smaller, less powerful, rockets are used for this purpose.
- Several satellites need to be deposited only in the lower earth orbits, which starts from about 180 km from earth’s surface and extends up to 2,000 km.
- For Higher Orbits:
- There are other satellites which need to go much deeper in space.
- Geostationary satellites, for example, have to be deposited in orbits that are about 36,000 km from earths’ surface.
- The planetary exploration missions also need their rockets to leave them much deeper in space.
- For such space missions, much more powerful rockets are used.
- In general, there is a trade-off between the weight of the satellite that needs to be launched, and the distance it needs to be taken to. The same rocket can take smaller satellites much deeper into space compared to a heavier satellite.
What are the Launch vehicles used by ISRO? |
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Satellite Launch Vehicle (SLV): |
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Augmented Satellite Launch Vehicle (ASLV): |
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Polar Satellite Launch Vehicle (PSLV): |
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Geosynchronous Satellite Launch Vehicle (GSLV): |
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Small Satellite Launch Vehicle (SSLV): |
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Reusable Rockets/ Future Rockets: |
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