How is a rocket not an engine?
Uli
'AS'

I have heard pedantic rocket ner.. er... "scientists" make the case that solid fuel rocket propulsion devices are "motors" not "engines". Liquid fuel rockets have "engines". So, since the Virgin Galactic ship has a hybrid solid/liquid fuel propulsion unit, one might say it has neither a motor or an engine. Definitely has a "MOP" though!

WB (not a rocket scientist)