I don't think developing a decent performance RD-180 sized gas generator kerosene engine would take *that long*. Maybe 5 years. But it would be a relatively sure thing to produce something, it's known territory. Of course, its performance would suck compared to the RD-180. So it would have to have some other advantages to be able to exist...
There's been considerable discussion of how single-engine stages provide better LOM stats for LVs. is there a comparison between single-chamber vs. multichamber engines in that regard?
William Barton - 11/2/2008 8:15 AM
There's been considerable discussion of how single-engine stages provide better LOM stats for LVs. is there a comparison between single-chamber vs. multi chamber engines in that regard?
multi chamber would allow for roll control The differences between an RD-180 and RS-68 as far as nozzles would be 1 less actuator (RD-180 has 2 each pitch and yaw, RS-68, has 1 each pitch, yaw and roll). this would be mean an RS-68 nozzle setup would be more reliable. Now take an SSME type engine: single nozzle and no generator output available for roll control. This means an additional roll control system would be needed. All these comparisons assume single engine installations.
Bottom line, it has to be evaluated at propulsion system level and not at the engine level