Indian Space Research Organisation successfully hot tests additively manufactured PS4 rocket engine
The Indian Space Research Organisation (ISRO) has reported the successful hot testing of a liquid rocket engine manufactured through Additive Manufacturing technology. The PS4 engine is used in the upper stage of the Polar Satellite Launch Vehicle (PSLV), and was tested for a duration of 665 seconds.
The PS4 engine, when manufactured in the conventional machining and welding route, has been in use for the fourth stage of PSLV and has a thrust of 7.33 kN in vacuum conditions. The same engine is also used in the Reaction Control System (RCS) of the first stage (PS1) of the PSLV. The engine uses the earth-storable bipropellant combinations of Nitrogen Tetroxide as oxidiser and Mono Methyl Hydrazine as fuel in pressure-fed mode and was developed by the Liquid Propulsion Systems Centre (LPSC), ISRO.
For this project, LPSC redesigned the PS4 engine specifically for the Additive Manufacturing process, thereby gaining considerable advantages. The Laser Beam Powder Bed Fusion (PBF-LB) technique employed has brought down the number of parts from 14 to a single-piece, and eliminated 19 weld joints, saving significantly on the raw material usage per engine (13.7 kg of metal powder compared to the 565 kg of forgings and sheets for conventional manufacturing process), reducing the overall production time by 60%.
As part of the development programme, detailed flow and thermal modelling, structural simulation, and cold flow characterisation of the proto hardware were carried out to gain confidence for the hot test. Consequently, four successful development hot tests of integrated engines were conducted for a cumulative duration of 74 seconds, which validated the engine performance parameters.
It is planned to use the additively manufactured PS4 engine in the regular PSLV programme.
