Gun-launched non-lethal projectile with solid propellant rocket motor

1. A gun-launched, non-lethal, anti-personnel cartridge, comprising:

a casing with a base;

propellant disposed in the casing; and

a non-lethal projectile disposed in the casing forward of the propellant and having a central longitudinal axis;

the projectile including a soft nose and a variable thrust, solid propellant rocket motor disposed aft of the nose, the rocket motor having a variable thrust profile that maintains a substantially constant kinetic energy of the projectile below a lethal threshold from a range of about 5 meters to about 400 meters.

2. The projectile of claim 1 , wherein the rocket motor includes a nozzle at an aft end.

3. The projectile of claim 2 , wherein the nose is made of one of foam, rubber, and plastic.

4. The projectile of claim 3 , wherein a caliber of the projectile is 40 mm.

5. The projectile of claim 3 , wherein the rocket motor includes a cylindrical combustion chamber centered on the central longitudinal axis and concentrically surrounded by a first propellant in the form of a tube, the first propellant being concentrically surrounded by a second propellant in the form of a tube wherein a burn rate and thrust of the first propellant are less than a burn rate and thrust of the second propellant.

6. The projectile of claim 3 , wherein the rocket motor includes a cylindrical combustion chamber centered on the central longitudinal axis and surrounded by a first propellant in the form of a tube and a second propellant in the form of a tube, the first and second propellants being disposed axially adjacent each other and centered on the central longitudinal axis, wherein a burn rate and thrust of the first propellant are less than a burn rate and thrust of the second propellant.

7. The projectile of claim 3 , wherein the rocket motor includes a plurality of motor segments that are concentric with the central longitudinal axis and arranged in series along the central longitudinal axis, each motor segment being symmetric around the central longitudinal axis and each motor segment including solid rocket motor propellant disposed symmetrically around a respective motor segment combustion chamber, wherein each motor segment has a different burn rate and thrust.

8. The projectile of claim 7 , wherein each motor segment combustion chamber has a different cross-sectional area.

9. The projectile of claim 8 , wherein the solid rocket motor propellant of each motor segment has a same chemical composition.

10. The projectile of claim 7 , wherein the solid rocket motor propellant of each motor segment has a different chemical composition.

11. The projectile of claim 7 , wherein each motor segment combustion chamber has a different geometric shape.

12. The projectile of claim 7 , wherein an aft-most motor segment has a burn rate and a thrust that is less than burn rates and thrusts of all the other motor segments.

13. The projectile of claim 12 , wherein the burn rates and thrusts of each motor segment increase from the aft-most segment to a forward-most segment.

14. A method, comprising:

providing the gun-launched, non-lethal, anti-personnel cartridge of claim 1 ;

launching the non-lethal projectile; and

maintaining the substantially constant kinetic energy of the projectile below the lethal threshold from the range of about 5 meters to about 400 meters.

15. The method of claim 14 , wherein the step of providing includes providing the rocket motor with a plurality of motor segments that are concentric with the central longitudinal axis and arranged in series along the central longitudinal axis, each motor segment being symmetric around the central longitudinal axis and each motor segment including solid rocket motor propellant disposed symmetrically around a respective motor segment combustion chamber, wherein each motor segment has a different burn rate and thrust.

16. A gun-launched, non-lethal, anti-personnel cartridge, comprising:

a casing with a base;

propellant disposed in the casing; and

a non-lethal projectile disposed in the casing forward of the propellant and having a central longitudinal axis;

the projectile including a soft nose and a variable thrust, solid propellant rocket motor disposed aft of the nose, the rocket motor having a variable thrust profile that maintains a substantially constant kinetic energy of the projectile below a lethal threshold from a range of about 5 meters to about 400 meters;

the rocket motor including a plurality of motor segments that are concentric with the central longitudinal axis and arranged in series along the central longitudinal axis, each motor segment being symmetric around the central longitudinal axis and each motor segment including solid rocket motor propellant disposed symmetrically around a respective motor segment combustion chamber, wherein each motor segment has a different burn rate and thrust and the burn rates and thrusts of each motor segment increase from the aft-most segment to a forward-most segment.