Bengaluru-based startup Astrobase Space on Friday unveiled 'Everest', India's first full-flow staged combustion (FFSC) rocket engine. Currently, SpaceX is the only company to have flown an FFSC engine in orbital rocket. The fully integrated 80-tonne-class engine uses liquid oxygen and liquid methane and is designed to produce about 800 kilonewtons of thrust in the vacuum of space.