gandalf@pro-electric.cts.com (Ken Hollis) (03/06/91)
Greetings and Salutations: From: dione@atlas.lpl.arizona.edu (Matt Cheselka) >Does anyone know at least what the solid fuel in the SRB's is made of? I am >trying to find out the actual combustion process, and anything more than just >the makeup of the fuel would be appreciated. The propellant formulation is as follows: Ingredient Percent By Weight ---------- ----------------- Reference 1 Reference 2 Ammonium Perchlorate (Oxidizer) 69.81 69.60 Aluminium (Fuel) 16.00 16.00 Iron Oxide (Burning Rate Accelerator) 0.19 0.40 PBAN POLYMER (Binder & Fuel) 12.00 12.04 Epoxy Curing Agent (ECA) 2.00 1.96 This is mixed together at the factory in Utah by Morton Thiokol and cured in the case into an 11 point star-shaped perforation in the forward segment & a double-truncated-cone configuration in each of the aft segments and aft closure. Note that the fuel & oxidizer are both present. It is about the consistency of an eraser. There is a solid rocket motor (SRM) ignitor at the very top of the solid grain. It is essentially a little SRM itself with a initiator propellant having a 30 point star and the main propellant grain having a 40 point star. The solid rocket motor ignitor fire commands cause redundant NSD's (NASA Standard Detonators) to fire through a thin barrier seal down a flame tunnel. This ignites a pyro booster charge which then ignites the propellant in the ignitor initiator.; and combustion products of this propellant ignite the solid rocket motor initiator which fires down the length of the solid rocket motor igniting the SRM propellant. Ken Hollis ---- ProLine: gandalf@pro-electric Internet: gandalf@pro-electric.cts.com UUCP: crash!pro-electric!gandalf ARPA: crash!pro-electric!gandalf@nosc.mil