ISRO’s PSLV: PS4 Engine Reimagined with 3-D Printing Tech

financialexpress.com:

Earlier this week (May 9, 2024), Indian Space Research Organisation (ISRO) accomplished the significant achievement of conducting a successful hot test of a liquid rocket engine that was produced using additive manufacturing (AM) technology. The test lasted 665 seconds and involved the utilization of the PS4 engine, which is part of the PSLV upper stage. AM, also known as 3D printing, involves layer-by-layer material addition to create objects from digital models, allowing for complex designs and efficient material usage.

“The PS4 stage is the fourth, and topmost, stage of the PSLV rocket, featuring two liquid engines. Each engine can produce 7.3 kiloNewtons (kN) of thrust in vacuum conditions, achieving a combined total of 14.6 kN. The PS4 engine employs Earth-storable bipropellants—nitrogen tetroxide as the oxidizer and monomethylhydrazine as the fuel, in a pressure-fed set-up. It was developed by ISRO’s Liquid Propulsion Systems Centre (LPSC),” explains Girish Linganna, Defence, and Aerospace analyst.

According to him, “Until now, the PS4 engine has been manufactured using traditional, or conventional, machining and welding methods. The PS4 engine is also utilized in the Reaction Control System (RCS) of the initial stage (PS1) of the PSLV rocket. The RCS controls a rocket, or spacecraft’s orientation, ensuring stability and manoeuvring using small thrusters, enabling precise control for such tasks as attitude control during ascent, precise trajectory adjustments for stage separation, payload deployment and docking manoeuvres.”

The engine was manufactured by M/s WIPRO 3D in India and underwent hot testing at the ISRO Propulsion Complex at Mahendragiri. The LPSC revamped the engine to align with the Design for Additive