The Indian Space Research Orgainsation (ISRO) built its first Polar Satellite Launch Vehicle (PSLV) in the early 90s. The 45 m tall PSLV with a lift-off mass of 295 tonne, had its maiden success on October 15, 1994, when it launched India’s IRS-P2 remote sensing satellite into a Polar Sun Synchronous Orbit (SSO) of 820 km altitude. Since its first successful launch in 1994, PSLV has launched nine Indian Remote Sensing satellites as well as two micro satellites HAMSAT and IMS-1 built by ISRO, as recoverable space capsule SRE-1, and fourteen small satellites for foreign customers into polar Sun Synchronous Orbits. Besides, it has launched one Indian meteorological satellite Kalpana-1 into geosynchronous Transfer orbit (GTO). PSLV has emerged as ISRO’s workhorse launch vehicle and proved its reliability and versatility by scoring continuous successes in launching multiple payloads to both SSO as well as GTO.
Considering the maturity of Polar Satellite Launch Vehicle (PSLV) demonstrated through various performances, PSLV is chosen for the first lunar mission. The upgraded version of PSLV viz., PSLV-XL (PSLV – C11) has been used to inject the 1380 kg mass spacecraft into a 257 X 22,858 km orbit.
PSLV has four stages, using solid and liquid propulsion systems alternately. Six starp-on motors augment the first stage thrust. PSLV-XL is the upgraded version of PSLV. In PSLV-XL, the six strap-on motors carry 4 tonne more propellant compared to PSLV; there is also an increase in the length of each strap-on.