Raptor has been claimed to be able to deliver "long life ... and more benign turbine environments".[1][2] Specifically, Raptor utilizes a full-flow staged combustion cycle, where all the oxidizer—with a low-fuel ratio—will power the oxygen turbine pump, and all the fuel—with a low-oxygen ratio—will power the methane turbine pump. Both streams—oxidizer and fuel—will be mixed completely in the gas phase before they enter the combustion chamber. Prior to 2014, only two full-flow staged-combustion rocket engines had ever progressed sufficiently to be tested on test stands: the Soviet RD-270 project in the 1960s and the Aerojet Rocketdyne Integrated Powerhead Demonstrator in the mid-2000s.[28][23][29]