Chennai-based spacetech startup Agnikul Cosmos has developed a single piece, fully 3D printed rocket engine called Agnilet, which can be directly used in a rocket. The engine will be used in the second stage of Agnikul's launch vehicle Agnibaan, CEO and Co-founder Srinath Ravichandran said. Launched in 2017, the startup is involved in building India's private small satellite launch vehicle.