For a gear train GL including a drive gear 33 and an idler gear 34 engaged with each other and a lock gear 35, provided are a first drive means 3A configured to linearly drive the lock gear 35 in forward and backward directions, a second drive means 3B configured to rotationally drive the drive gear 33 in normal and reverse directions, and a controller C configured to control the both drive means 3A and 3B. The controller C starts driving the lock gear 35 at the time of an unlocking operation, from an engagement position toward the disengagement position through the first drive means 3A, and when the drive is started, the controller C drives the drive gear 33 into one of normal and reverse directions and into the other direction through the second drive means 3B with a polarity reversal in a predetermined cycles T1 and T2.

A method and concept for employing a T-sin-alpha kill vehicle with energy flexibility is disclosed. The energy flexibility method applies divert pulses at multiple phases of the kill vehicle flight time and allows for range extension to increase the kill vehicle coverage of targets outside the normal reach, reaction to target updates, removal of navigation error, and homing divert to intercept the target. Each of these capabilities is essential to the successful intercept of exo-atmospheric ballistic targets in their midcourse phase of flight. A flight vehicle includes a main body, a number of attitude control mechanisms, a control unit, a divert system, a sensor unit, and an attitude control system. The divert system provides acceleration of the flight vehicle in a desired direction. The sensor unit tracks a target along a line of sight (LOS) of the sensor unit. The attitude control system maintains an orientation of the main body.

For a gear train GL including a drive gear 33 and an idler gear 34 engaged with each other and a lock gear 35, provided are a first drive means 3A configured to linearly drive the lock gear 35 in forward and backward directions, a second drive means 3B configured to rotationally drive the drive gear 33 in normal and reverse directions, and a controller C configured to control the both drive means 3A and 3B. The controller C starts driving the lock gear 35 at the time of an unlocking operation, from an engagement position toward the disengagement position through the first drive means 3A, and when the drive is started, the controller C drives the drive gear 33 into one of normal and reverse directions and into the other direction through the second drive means 3B with a polarity reversal in a predetermined cycles T1 and T2.

A drag reduction system, more specifically a forward mounted drag reduction system for use on an extended range artillery shell, includes a forward end comprising a fuse, an aft located base unit and located therebetween a shell body defining a cavity which comprises a payload, a forwardly located gas generator capable of generating a gas flow, and an ignition device to ignite the gas generator after the shell is launched.