Henry Spencer wrote:

In article ,
John Pelchat wrote:


Thanks for a great reply, one follow-one: Part of your reply spoke of
dumping exhaust overboard. In photos of some launch vehicles, you see
a rather non-propulsive flame to one side of the engine exhaust,
especially the older Atlas vehicles . . . is that the same exhaust?



No, the side flames on the old Atlases (there are two, 180deg apart) are
its vernier engines, used for roll control after booster-engine jettison,
and for final velocity trim after sustainer-engine cutoff.


I think he was referring to the big flame from the turbopump exhaust, it was very noticeable on Atlas; speaking of which, was it Jupiter that swiveled the turbopump exhaust pipe for roll control? I know some launch vehicle did this.

Pat