2014-10-202014-10-202014-07-13978-0-692-38220-2ICES-2014-203http://hdl.handle.net/2346/59669Tucson, ArizonaJonathan G. Metts, Sierra Nevada Corporation, USAStephen W. Miller, Sierra Nevada Corporation, USAJeff Johnson, Orbital Technologies (ORBITEC), USAGregory Quinn, Hamilton-Sundstrand Space Systems International, USAThe 44th International Conference on Environmental Systems was held in Tuscon, Arizona, USA on 13 July 2014 through 17 July 2014.The Dream Chaser® human spacecraft utilizes excess nitrous oxide propulsion oxidizer as an evaporant to provide heat rejection for the vehicle’s Active Thermal Control System. This capability is provided by a nitrous oxide boiler, currently in development. Performance analysis and test results indicate that a heat exchanger boiling nitrous oxide with a propylene glycol/water coolant fluid can provide the required heat rejection for Dream Chaser while preventing freezing or incomplete phase transition in the boiler unit. Integration of nitrous oxide boiler technology will result in a net system mass savings.engPresentation