Stage separation and thrust reduction apparatus

An apparatus for use with a multi-stage missile, the missile having an upper stage detachably connected to a forward end of a lower stage rocket motor, the lower stage rocket motor including a combustion chamber and configured with a piston orifice at its forward end, the apparatus comprising:

• a piston positioned in the forward end of the lower stage rocket motor, the piston being in fluid communication with the combustion chamber of the lower stage rocket motor and being configured with a plurality of venting passages, the piston being further configured for deployment from a stowed position, in which the piston is held in place by the connected upper stage and in which the venting passages are sealed, to an extended position, in which the venting passages are unsealed for venting the combustion chamber;
• a piston guide attached within the piston orifice of the lower stage rocket motor, the piston guide being aligned to guide the piston from the stowed position toward the extended position;
• and
• means for detaching the upper stage from the lower stage rocket motor to thereby permit deployment of the piston from the stowed position toward the extended position.

An apparatus for use with a multi-stage missile, the missile having an upper stage detachably connected to a forward end of a lower stage rocket motor, the lower stage rocket motor being disposed about a combustion chamber and being configured with a piston orifice at its forward end, the apparatus comprising:

• a piston positioned in the forward end of the lower stage rocket motor, the piston including a substantially cylindrical metal shell configured with a plurality of venting passages, the metal shell disposed about heat-resistant material, the piston being in fluid communication with the combustion chamber, the piston being further configured for deployment from a stowed position, in which the piston is held in place by the connected upper stage and in which the venting passages are sealed, to an extended position, in which the venting passages are unsealed for venting the combustion chamber;
• a piston guide attached within the piston orifice of the lower stage rocket motor, the piston guide being aligned to guide the piston from the stowed position toward the extended position;
• an attachment bolt connecting the upper stage and the lower stage rocket motor;
• an explosive detachment charge near the attachment bolt, the charge configured such that detonation of the charge causes the attachment bolt to break into fragments, thereby releasing the upper stage from the lower stage rocket motor to permit deployment of the piston from the stowed position toward the extended position;
• and
• an energy absorbing material positioned in the lower stage rocket motor to receive and retain any fragments of the attachment bolt not retained in the upper stage.