public void makeMissile() {
        Vector3f pos = spaceCraft.getWorldTranslation().clone();
        Quaternion rot = spaceCraft.getWorldRotation();
        Vector3f dir = rot.getRotationColumn(2);

        Spatial missile = assetManager.loadModel("Models/SpaceCraft/Rocket.mesh.xml");
        missile.scale(0.5f);
        missile.rotate(0, FastMath.PI, 0);
        missile.updateGeometricState();

        BoundingBox box = (BoundingBox) missile.getWorldBound();
        final Vector3f extent = box.getExtent(null);

        BoxCollisionShape boxShape = new BoxCollisionShape(extent);

        missile.setName("Missile");
        missile.rotate(rot);
        missile.setLocalTranslation(pos.addLocal(0, extent.y * 4.5f, 0));
        missile.setLocalRotation(hoverControl.getPhysicsRotation());
        missile.setShadowMode(ShadowMode.Cast);
        RigidBodyControl control = new BombControl(assetManager, boxShape, 20);
        control.setLinearVelocity(dir.mult(100));
        control.setCollisionGroup(PhysicsCollisionObject.COLLISION_GROUP_03);
        missile.addControl(control);


        rootNode.attachChild(missile);
        getPhysicsSpace().add(missile);
    }
initial orientation of the tank (in world/physics-space coordinates)
jme3-examples/src/main/java/jme3test/bullet/TestHoveringTank.java