The Indian Space Research Organisation (ISRO) celebrated a remarkable milestone on Wednesday as it achieved its 100th mission and laid out an ambitious plan to complete another 100 launches in the next five years. Commencing its journey with the Satellite Launch Vehicle (SLV) in 1979, ISRO has reached this significant milestone in just 46 years. A standout feature of this achievement is the impressive performance of the Polar Satellite Launch Vehicle (PSLV), which has been pivotal with a total of 62 missions.
The PSLV has grown into ISRO's most reliable rocket, known for its consistent performance and unmatched reliability. Following the PSLV, the Geosynchronous Satellite Launch Vehicle (GSLV), equipped with an indigenous cryogenic upper stage, has conducted 17 missions. The LVM3, also known as the Geosynchronous Satellite Launch Vehicle MkIII and ISRO's heaviest rocket, has completed 7 missions, while the Small Satellite Launch Vehicle (SSLV) follows with 3.
Other notable vehicles include the Reusable Launch Vehicle, Test Vehicle (TV), and Pad Abort Test (PAT).
Often referred to as ISRO’s “trusted workhorse,” the PSLV has effectively been used to place various satellites into precise Low Earth Orbits. Standing at 44.4 meters tall, it can carry payloads of up to 1,750 kg to Sun-Synchronous Polar Orbits at an altitude of 600 km. Due to its reliability, the PSLV has also been instrumental in launching satellites into Geostationary and Geosynchronous orbits, including those from the IRNSS constellation.
The PSLV comes in four different variants: PSLV-CA, PSLV-DL, PSLV-QL, and PSLV-XL. Its first flight, PSLV-D1, took place on September 20, 1993, although it ended in failure. However, the rocket quickly turned its fortunes around with its first successful launch in October 1994, establishing itself as ISRO's most reliable and versatile launch vehicle.
Some of its notable missions include the groundbreaking Chandrayaan-1 in 2008 and the Mars Orbiter Mission in 2013, which scientists proudly refer to as “feathers in the hat” for the PSLV.
The Sriharikota spaceport, situated around 135 km east of Chennai, boasts two launch pads. The first pad entered service in September 1993 with the PSLV/IRS-P1 mission, while the second began operations in May 2005 with the PSLV-Cartosat-1 launch, as confirmed by ISRO officials.
The GSLV has posed its own set of challenges for ISRO due to the complexities of its technology. At one point, it earned the nickname “naughty boy” due to some repeated failures. Fortunately, recent successful launches, such as the flawless weather observation satellite INSAT-3DS mission last year, have allowed ISRO to breathe a sigh of relief. One scientist humorously remarked that the “naughty boy has matured into an obedient, disciplined boy.”
Inputs from PTI