Used in Shuttle Orbiter Orbital Maneuvering System (OMS); proposed for Shuttle C OMS. The Shuttle Orbiter carries two OMS pods (name coined by Aerojet), each housing a single Aerojet OM Engine for orbit insertion, maneuvering, and re-entry initiation. They are capable of 100 missions and 500 starts in space.. Manufacturer: AeroJet Propulsion Division. First Flown: April 12th, 1981, on the Orbiter Columbia. Mounting: gimballed ( 7 degrees yaw, 6 pitch by two electromechanical actuators for thrust vector control. Engine Cycle: pressure-fed (improvement underway for pump-fed). Oxidizer: 6743 kg nitrogen tetroxide in each pod (pods can be cross-linked). Fuel: 4087 kg of monomethyl hydrazine in each pod (pods can be cross-linked). Mixture Ratio: 1.65:1. Cooling Method: fuel regenerative for chamber, radiative for nozzle. Burn Time: qualified for 500 starts, 15 hr/100 mission life, longest firing 1250 sec, de-orbit. burn typically 150-250 secs.