Improved igniter compositions for rocket motors are provided which, when cured, are non-volatile and are capable of igniting under vacuum conditions and burning steadily at reduced pressures. Said igniter compositions comprise: (a) about 11% to about 13% hydroxyl terminated polybutadiene binder prepolymer; (b) about 0.7% to about 2.0% polyfunctional isocyanate curing agent for said binder prepolymer; (c) about 2.0% to about 20% metallic powder fuel; (d) about 20% to about 40% large particle size ammonium perchlorate; (e) about 30% to about 50% small particle size ammonium perchlorate; (f) about 0.05% to about 5.0% non-volatile burning rate catalyst; (g) about 0.05% to about 0.50% bonding agent capable of wetting the solids in the composition by said binder prepolymer and of chemically coupling with said ammonium perchlorate; and (h) about 0.01% to about 0.20% ammonia scavenger wherein all percentages are by weight based on the total weight of the compositions.

Igniting rocket propellants under vacuum conditions

A consumable sealed plastic cup containing ignition pellets is assembled into end cap at the forward end of a solid fuel rocket motor with sufficient clearance to allow leak test gas to bypass it and thereby expose the port seals of the through bulkhead initiators for leak checking.

Igniter pellet cup

The present invention relates to a mechanical and insulating connection between, on the one hand, a filament-wound casing, constituting a wall for the combustion chamber of a solid propellant rocket motor, and on the other hand, a hot nozzle made from a heat-conducting refractory material wherein said connection consists of a single connecting ring fixed to the nozzle and resiliently connected to the wound casing, which ring is made from a low density insulating material, resistant to mechanical forces, as well as to mechanical shocks and thermal stresses, preferably a composite material with multidirectional reinforcements and a ceramic matrix.

Mechanical and insulating connection between a nozzle and the filament-wound casing of the combustion chamber of a solid propellant rocket motor

A rocket motor nozzle has a nozzle core that defines a nozzle passage through which combustion products travel during flight. The erosive forces created by the combustion products are longitudinally distributed over the nozzle core so that the nozzle's smallest area remains substantially constant in spite of the erosion. An inner surface of the nozzle core defines the nozzle passage. The inner surface includes an entry region which defines a nozzle entry, an exit region which defines an exit, and an elongate erosion region which defines an erosion passage between the entry and exit. The erosion region length is greater than the average smallest passage diameter, thereby allowing the location of the erosion focus along the erosion region to vary over time as a result of erosion of the erosion region. The nozzle core is formed of a fibrous composite material which is selected according to the type of propellant used and which includes fibers oriented transverse to the erosion passage to resist erosion.

Distributed erosion region rocket motor nozzle

A nozzle for use in a hot gas valve is provided that includes a housing, an insert, and a throat retainer. The housing is constructed of an insulating material and has a flow path formed therein. The flow path has a throat section. The insert is made of material capable of maintaining structural integrity at a temperature up to about 5000° F. and is disposed at least partially in the throat section and has a flow path extending therethrough in fluid communication with the housing flow path. The throat retainer is constructed of material having insulating and ablative properties and is coupled between the housing and the insert and configured to retain the insert within the housing throat section.

Throat retention apparatus for hot gas applications

A solid propellant rocket motor having a controlled rate of thrust buildup to a desired thrust level by the combined utilization of a regressive-burning controlled flow solid propellant igniter and a progressive-burning main solid propellant charge wherein the igniter is capable of operating in a vacuum and sustaining the burning of the propellant below its normal L* combustion limit until the burning propellant surface and motor chamber pressure has increased sufficiently to provide a stable motor chamber pressure.

https://ntrs.nasa.gov/api/citations/19730016057/downloads/19730016057.pdf

Fletcher J

Papers

Solid propellant rocket motor