Dec 232012
In order to aid separation of the S-IB first stage and the interstage (the connector between the S-IB and the S-IVb second stage) from the upper stage of the Saturn Ib, the interstage was equipped with 4 solid rocket motors that fired “upwards.” This would push the ring-shaped structure aft and away from the S-IVb quickly, reducing the risk to the aft-protruding J-2 engine. Each Thiokol “Recruit” motor produced an average thrust of 36,720 pounds for 1.52 seconds, burning 267 pounds of propellant.
