PS0M-XL Strap-on Booster Motor Cases (PSLV / GSLV Mk II)

The PS0M-XL is the solid-propellant strap-on booster motor casing used on ISRO’s Polar Satellite Launch Vehicle (PSLV) and GSLV Mk II, six of which are clustered around the first stage core to augment lift-off thrust. Walchandnagar Industries (WIL) has fabricated strap-on booster casings for these vehicles since the 1980s, when the first hardware was delivered for the ASLV programme, continuing seamlessly into series production for PSLV from 1987 onward. As of the current production run, WIL has supplied 141 strap-on booster units for the PSLV/GSLV Mk II programme. The casings are large-diameter, pressure-vessel structures fabricated from aerospace-grade high-strength steel and formed, welded and heat-treated to exacting ISRO specifications, then precision-machined and pressure-tested before dispatch to ISRO’s Vikram Sarabhai Space Centre / Satish Dhawan Space Centre integration facilities. This hardware has enabled the launch of ROHINI, SROSS, IRS and G-SAT series satellites as well as India’s Chandrayaan-1 lunar mission and the Mangalyaan Mars Orbiter Mission. WIL’s current manufacturing capacity supports delivery of strap-on booster hardware for up to 12 PSLV flights per year, produced using established process control for metal forming, joining, heat treatment, fabrication and precision machining of large, complex-geometry rocket motor cases.