PSLV-XL is the upgraded version of Polar Satellite Launch Vehicle in its standard configuration boosted by more powerful, stretched strap-on boosters with 12 tonne propellant load. Weighing 320t at lift-off, the vehicle uses larger strap-on motors (PSOM-XL or S12) to achieve higher payload capability. On 29 December 2005, ISRO successfully tested the improved version of strap-on booster for the PSLV. The first use of PSLV-XL was the launch of Chandrayaan-1 by PSLV C11. The payload capability for this variant is 1,800 kg to SSO.