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

On Tue, Jun 08, 2004 at 06:31:55PM -0700, David Weinshenker wrote:

> I suppose that with sufficient throttling capability, it might be possible 
> to start each engine at reduced thrust, such that the total thrust stayed 
> below the vehicle's liftoff weight - then when they're all running at partial 
> power, bring them up to full thrust together.
> 
> -dave w

That's exactly what was planned for the Alpha and Bravo class vehicles
back when I first designed them in the late '80s. Bring the engines
online at reduced thrust until you had reliable "bouyancy" - i.e.
total thrust to 50% vehicle mass - and then throttle up from there. 
That part of the launch sequence goes:

	- Get clearance for departure from local tower
	- Captain give "Egines to idle" command
	- Bring engine thrust up to 50% of mass
	- Get arrival clearence from destination tower if SubOrbital
	- Captain gives "Up Ship!" command
	- "Boosting!" from Propulsion Engineer as you throttle up
	- Ship lifts from pad and leaps skyward

Ok ... it's a little dramatic, but I think visually and that's the way
I've always seen it.

    Michael

----------------------------------------------------------------------
Michael Wallis   KF6SPF       (408) 396-9037        [email protected]

"And I keep praying that this faith we hold in common keeps showing up
 in the good things we do, and that people recognize Christ in all of
 it."           Philemon 1:6