🚀 go-pugleaf

In article <8796@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) writes:
> Engines, like lightbulbs, generally do not have a single specific setting
> for which they are designed, in the sense that all other settings work
> poorly or not at all.  

Sorry, but I don't believe this is true.  The Shuttle engine is rather rare
in that it can be throttled over almost a 2:1 range.  Most rocket engines
are, in fact, designed to run at a particular setting.  This is primarily
because most rocket engines were designed before flexible control systems
were available.  They use pneumatic/hydraulic/fluidic controls (the
pinnacle of late-50's technology) which are fussy about their set-points.

This fact is what got the early OSCARs into space.  They couldn't throttle
down their boosters to match the weight of the primary payload; instead,
they had to carry ballast.  Don Stoner had the bright idea to carry
interesting ballast, which led to the OSCARs.

Stu