Country of Origin: Germany
3-D Test: 19.1 x 12.1 x 19.1cm (7 1/2 x 4 3/4 x 7 1/2 in.)
The V-2, the world's first ballistic missile, was aimed in part by this device. During launch, a component of this device sensed the rocket's acceleration, and from that measurement the device computed the missile's velocity. When the V-2 reached the velocity predetermined to hit a given target, its engine was commanded to shut down. For the rest of the mission, the V-2 coasted to its target in a free-fall, or "ballistic" trajectory.