Barry E Kerrigan

US Patent:

48194263, Apr 11, 1989

Filed:

May 8, 1987

Appl. No.:

7/047760

Inventors:

Victor Singer - Newark DE
Barry E. Kerrigan - Newark DE

Assignee:

Morton Thiokol, Inc. - Chicago IL

International Classification:

F02K 906

US Classification:

60250

Abstract:

A rocket propelled vehicle includes a lower stage solid propellant rocket motor and at least one upper stage solid propellant rocket motor. Each of the rocket motors includes a case, a nozzle and a solid propellant having a central combustion chamber, with the case of the lower stage motor, in a preferred embodiment, being open at the forward end and the case of the upper stage motor being open at the aft end and forming a continuation of the open end of the lower stage case, with a layer of slow burning material cast on the surface defining the central combustion chamber of the upper stage solid propellant, and with ignition of all stages being accomplished approximately simultaneously through operation of a single ignition system. Pressurization of the lower and upper stages during burning of the lower stage propellant counteracts and substantially eliminates compressive stresses in the upper stage vessel membranes, which compressive stresses are induced by transmission of lower stage thrust to the upper stages and the payload beyond by superimposing tensile stresses therein, and additionally provides a source for the secondary discharge of gases. Such gaseous discharge may be used to create a boundary layer surrounding the skin of the vehicle for diminishing friction with the medium through which the vehicle flies, and may also be used for thrust vector control to steer the vehicle.