These pods also contained the Orbiter's aft set of reaction control system (RCS) engines, and so were referred to as OMS/RCS pods. The OM engine and RCS systems both burned monomethylhydrazine (MMH) as fuel, which was oxidized with dinitrogen tetroxide (N2O4), with the propellants being stored in tanks within the OMS/RCS pod, alongside other fuel and engine management systems. When full, the pods together carried around kilogram (lb) of MMH and kilogram (lb) of N2O4, allowing the OMS to produce a total of around foot per second (m/s) of delta-v with a 65,000-pound (29,500 kg) payload. File:OMS Pod schematic.png|OMS/RCS pod schematic File:OMS pod.jpg|An OMS pod detached from an Orbiter for maintenance