The Indian Space Research Organisation (ISRO) has announced a significant milestone, confirming the successful completion of a hot test for a liquid rocket engine produced using additive manufacturing (AM) technology, also known as 3D printing. This engine is designated for use in the PS4, the upper stage of ISRO's Polar Satellite Launch Vehicle (PSLV).

The conventionally manufactured PS4 engine underwent a redesign by ISRO to align it with additive manufacturing techniques, a process referred to as Design for Additive Manufacturing (DfAM). The Times of India reported that this innovative approach has resulted in significant advantages.

ISRO reported that the manufacturing process utilised the Laser Powder Bed Fusion technique, resulting in a reduction of engine components from 14 to a single piece and the elimination of 19 weld joints. This streamlined design significantly reduced raw material usage per engine from 565kg to just 13.7 kg of metal powder. Additionally, it reduced overall production time by 60%.

ISRO's Liquid Propulsion Systems Centre (LPSC) developed the PS4 engine, which uses a bipropellant combination of nitrogen tetroxide as the oxidizer and monomethyl hydrazine as the fuel. The manufacturing of the additively manufactured engine was undertaken by the Indian industry partner, Wipro 3D. ISRO conducted the hot testing at its Propulsion Complex in Mahendragiri.

Before the successful 665-second hot test, ISRO executed a comprehensive development program. This program encompassed detailed flow and thermal modeling, structural simulations, cold flow characterisation of the proto hardware, and four successful developmental hot tests of the integrated engine, totalling 74 seconds in duration. These rigorous tests, as reported by The Times of India, validated the engine's performance parameters.

The successful hot testing of the 3D-printed PS4 engine marks a significant advancement in utilising additive manufacturing technology for rocket engines in the future. ISRO stated that this development lays the groundwork for integrating the additively manufactured PS4 engine into the regular PSLV program, introducing a new era of advanced manufacturing techniques for India's space missions.

Image source: The Economic Times