A successful first flight of the Tactical Tomahawk cruise missile has brought the Navy close to the point of starting mass production. Also known as the Block 4 Tomahawk, the primary improvement is a two-way satellite datalink allowing the US to retarget the missile while it is in flight and to watch the target through the missile during the final seconds of its flight. The Tactical Tomahawk has a range of over 1000 kilometers, costs half as much as the previous model (which cost up to $1.4 million). The low cost comes at a price, the new Tomahawk cannot be fired from submarines.--Stephen V Cole