Everything you never knew you wanted to know about the Mercury Project
Posigrade rocket system
From RixWiki
This article is organized like the Posigrade Rocket System section of the SEDR-104 Mercury familiarization manual except that the descriptions of the variations for the test capsules have been incorporated into the relevant sections.
System Description
System Operation
Posigrade Rocket
The three posigrade rockets provided for positive separation between the spacecraft and the launch vehicle.
Many modelers paint the nozzles of the posigrade rockets red. For most if not all of the Mercury spacecraft this is incorrect. The nozzles themselves appear to have been a dull aluminum color towards the ends, but more polished near the throat of the nozzle. A bronze color ring was at the base.
Figures PRS-SC18-1 through PRS-SC18-4 show the posigrade nozzles installed in the retro package of spacecraft 18. Note the colors. Click on the thumbnails to see the full size photos which are clearer.

