India 

ISRO achieves breakthrough in rocket engine technology with successful hot testing of Additively Manufactured PS4 engine for PSLV, reducing parts and welds, saving material and time.

India's space agency, the Indian Space Research Organisation (ISRO), has marked a significant achievement in rocket engine technology. On May 9, 2024, ISRO successfully conducted hot testing of a liquid rocket engine, manufactured using Additive Manufacturing (AM) technology. This milestone heralds a new era in space propulsion systems, particularly for the PS4 engine of the Polar Satellite Launch Vehicle (PSLV) upper stage.

Traditionally, the PS4 engine has been fabricated through conventional machining and welding methods. However, by embracing the Design for Additive Manufacturing (DfAM) concept, ISRO's Liquid Propulsion Systems Centre (LPSC) revamped the engine's design, making it conducive to AM techniques. The engine, which previously comprised 14 parts and necessitated 19 weld joints, has now been consolidated into a single-piece structure through Laser Powder Bed Fusion technology.

The advantages of this transition are manifold. Not only has it significantly reduced the number of components and weld joints, but it has also led to substantial savings in raw material usage. For instance, while the conventional manufacturing process required 565 kg of forgings and sheets, the AM approach consumes only 13.7 kg of metal powder per engine. Moreover, the overall production time has been slashed by 60%.

Crucially, the manufacturing of this innovative engine was entrusted to the Indian industry, with M/s WIPRO 3D playing a pivotal role. The engine underwent rigorous testing at the ISRO Propulsion Complex in Mahendragiri, where it demonstrated exceptional performance characteristics.

Prior to the hot test, ISRO conducted thorough simulations and characterizations to ensure the engine's readiness. This included detailed flow and thermal modeling, structural simulations, and cold flow characterizations. Subsequently, a series of developmental hot tests, totaling 74 seconds, validated the engine's performance parameters. Encouraged by these successes, ISRO proceeded with the full qualification test, which lasted 665 seconds. The results confirmed that all performance parameters met expectations.

Looking ahead, ISRO plans to integrate the AM PS4 engine into its regular PSLV program. This transition not only underscores ISRO's commitment to innovation but also paves the way for enhanced efficiency and reliability in space missions.

In summary, ISRO's achievement in hot testing the AM PS4 engine signifies a paradigm shift in rocket engine manufacturing. By leveraging cutting-edge AM technology and meticulous testing protocols, ISRO has demonstrated its prowess in advancing space propulsion systems, setting a precedent for future endeavors in space exploration.