Evolution of Indian Launch Vehicles
A launch vehicle, commonly known as a rocket, is a powerful machine used to carry satellites or spacecraft from the Earth’s surface into space. The Indian Space Research Organisation (ISRO) did not build its most powerful rockets overnight. The development of Indian launch vehicles occurred in a step-by-step, evolutionary process, starting from simple experimental rockets to today’s heavy lifters.
The Stages of Evolution
- Satellite Launch Vehicle (SLV-3): This was India’s first experimental satellite launch vehicle. It was a simple, four-stage solid-propellant rocket. In 1980, SLV-3 successfully placed the Rohini satellite into Low Earth Orbit (LEO), making India the sixth member of the exclusive club of space-faring nations.
- Augmented Satellite Launch Vehicle (ASLV): Designed to increase the payload capacity of the SLV-3, the ASLV was a five-stage solid-propellant rocket. It served as a crucial stepping stone to test new technologies, such as strap-on boosters, which are extra rockets attached to the side for more thrust.
- Polar Satellite Launch Vehicle (PSLV): Known as the “Workhorse of ISRO,” the PSLV is India’s most reliable and famous rocket. It was the first Indian launch vehicle to be equipped with liquid stages. The PSLV has successfully launched hundreds of Indian and foreign satellites, including historic missions like Chandrayaan-1 (Moon) and Mangalyaan (Mars).
- Geosynchronous Satellite Launch Vehicle (GSLV Mk II): To launch heavier communication satellites higher into space (Geosynchronous Transfer Orbit), India needed more power. The GSLV uses a complex Cryogenic Upper Stage (using liquid oxygen and liquid hydrogen at extremely low temperatures), which was successfully developed indigenously by Indian scientists.
- Launch Vehicle Mark-3 (LVM3): Formerly known as GSLV Mk III, this is currently ISRO’s heaviest and most powerful rocket. It is designed to carry very heavy satellites (up to 4,000 kg) into high orbits. LVM3 was the launch vehicle used for the successful Chandrayaan-2 and Chandrayaan-3 missions, and it is the designated rocket for India’s upcoming human spaceflight mission, Gaganyaan.
- Small Satellite Launch Vehicle (SSLV): This is the newest addition to ISRO’s fleet. It is a cost-effective, quickly assembled rocket designed specifically to launch smaller commercial satellites into Low Earth Orbit on demand.
