Abstract: An improved method of manufacture is provided for producing a channeled wall thrust nozzle (10) of the type used to define a thrust chamber (12) in a jet or rocket engine. The method utilizes a precision formed mandrel (20) having an external geometry conforming generally to the converging-diverging shape of the desired thrust chamber (12), and further including longitudinally extending slots (24) for receiving channel separation ribs (26) which may be formed by die cutting from sheet stock. The channel spaces (16) between the separator ribs (26) are filled with a removable casting material (30) such as wax, and an outer housing shell (32) for the thrust nozzle is mounted about and secured to the separator ribs. The mandrel (20), which is transversely split at the throat of the thrust chamber (12), is then removed to expose the radially inboard margins of the separator ribs (26) for precision machining, followed by mounting of an inner housing shell (34) to the separator ribs.

Abstract: A ball bearing assembly for operation immersed in liquid oxygen at pressures in excess of 1000 psi and at rotational speeds in excess of 10,000 revolutions per minute. A bearing assembly comprising an inner and outer race, a plurality of spherical ball bearings dispersed therebetween and a cage member for maintaining the bearings in spaced-apart relation with respect to one another. The improvement comprises forming the cage member from a liquid oxygen compatible porous metal impregnated with a liquid oxygen compatible polyhalogenated hydrocarbon for adding lubricity to the cage member. The preferred porous metal is a 300 series CRES alloy and the preferred polyhalogenated hydrocarbon is either fluorinated ethylenepropylene or polytrichlorotrifluoroethylene.

Abstract: A protective laminate has high impact and heat resistance suitable for use as an exterior shield for missile structures and substructures. The laminate includes one or more outer plies of a resin-impregnated woven fabric made from high tensile strength fibers in which a majority of the fibers in each ply extend in the same direction. The laminate also includes one or more sub-plies of a resin-impregnated woven fabric made from high tensile strength fibers woven in a generally uniform pattern. Each of the sub-plies is coated with a separate layer of finely divided hollow microspheres. The woven fabric plies overlie one another and the resin system bonds the plies together at the interface between them to form the protective laminate. In one embodiment the fibers are aramid fibers and the resin system contains an elastomer to bind the fabric plies together in a rubbery matrix. The microspheres are crushable to absorb energy upon impact.