Re: Re: Multiple engines (was RE: Liquox)

On Tue, 2004-06-08 at 09:32, David Weinshenker wrote:

> I'm not John, and he'd be the one to speak definitively, but I'm not sure 
> that I agree with your assessment of these relative difficulties: what is 
> the new "hard engine problem"? The single engine is using the same propellant
> system as the four-engine setup, and requires less plumbing - and it reduces
> the influence of the engine characteristics on the control problem.

	I suspect that the small variations in thrust characteristics of the
four engines will require some constant deflection of the jet vanes.
This will in turn increase the power requirements and increase the
steering losses, not to mention wear on the jet vanes themselves. I
think it would be more efficient to go to 1-axis gimballing on each
engine; it's easy enough with a single room-temp propellant.

	-p