This document summarizes the cryogenic engine used for India's first geo-synchronous satellite launch vehicle. The engine used liquid oxygen and liquid hydrogen propellants, providing an high specific impulse of 450 seconds for improved efficiency. Key specifications of the cryogenic engine are provided such as its thrust rating, chamber pressure, nozzle area ratio, and mass. While cryogenic engines offer benefits like non-toxic propellants and high performance, they also pose challenges including the need for complex low-temperature storage and transfer systems as well as ignition challenges. The launch discussed ultimately failed, but future success is hoped for to help launch increasingly heavier satellites.