In order to investigate the vacuum plume effects of a large-thrust hydrogen/oxygen engine

a shrink ratio gaseous hydrogen/oxygen engine of 60N-thrust with torch igniting method was designed. The mass flow rate was controlled by a sonic nozzle with ball-end seal

such that 3 sealing faces were reduced in every assembly compared to the traditional one. The vacuum igniting scheme was designed

and the feasibility of igniting with electric spark was confirmed in theory. The experiment system was devised and the heat test run was conducted in both ground and vacuum conditions. The results show that when the chamber pressure reaches nominal 0.6MPa

the thermal protective structure of the engine works well

the experiment system is reasonable

and the scheme of igniting with electric spark in vacuum is feasible

laying a solid foundation for the vacuum plume effect investigation.