Polar Satellite Launch Vehicle - Variants

Variants

ISRO has envisaged a number of variants of PSLV to cater to different mission requirements. There are currently three operational versions of the PSLV — the standard (PSLV), the core-alone (PSLV-CA) without the six strap-on booster motors, and the (PSLV-XL) version, which carries more solid fuel in its strap-on motors than the standard version. All the three versions have proved to be unalloyed successes. These configurations provide wide variations in payload capabilities ranging from 600 kg in LEO to 1900 kg in sun synchronous orbit.

PSLV (Operational)

The standard version of the PSLV has four stages using solid and liquid propulsion systems alternately and six strap-on boosters. It currently has capability to launch 1,678 kg to 622 km into sun synchronous orbit.

PSLV-CA (Operational)

The PSLV-CA, CA meaning "Core Alone", model premiered on April 23, 2007. The CA model does not include the six strap-on boosters used by the PSLV standard variant. Two small roll control modules and two first stage motor control injection tanks were still attached to the side of the first stage. The fourth stage of the CA variant has 400 kg less propellant when compared to its standard version. It currently has capability to launch 1,100 kg to 622 km sun synchronous orbit.

PSLV-XL (Operational)

PSLV-XL is the uprated version of Polar Satellite Launch Vehicle in its standard configuration boosted by more powerful, stretched strap-on boosters. Weighing 320 tonnes at lift-off, the vehicle uses larger strap-on motors (PSOM-XL) to achieve higher payload capability. PSOM-XL uses larger 13.5m, 12 tonnes of solid propellants instead of 9 tonnes used in the earlier configuration of PSLV. On 29 December 2005, ISRO successfully tested the improved version of strap-on booster for the PSLV. The first version of PSLV-XL was the launch of Chandrayaan-1 by PSLV-C11. The payload capability for this variant is 1800 kg compared to 1600 kg for the other variants. Other launches include the RISAT Radar Imaging Satellite and GSAT-12.

PSLV-HP (Under development / Proposed)

As reported on the website of The New Indian Express newspaper (April 26, 2007), PSLV project director N Narayanamoorthy spoke of another version being planned called the PSLV-HP, standing for ‘high performance.’ It will have improved strap-ons motors, and the payload capability will be raised to 2000 kg. The HP version will be used to launch a constellation of seven navigation satellites between 2010 and 2012. Among other things, the efficiency of the stage 4 engine will be improved in this version.

PSLV-3S (Under development / Proposed)

ISRO is also considering the development of a three-stage version of the rocket without six strap-on boosters (with the second stage of the four-stage version removed) which will be capable of placing 500 kg to LEO.