Tom Clancy's op-center_ acts of war - Tom Clancy [138]
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FORTY-SEVEN
Tuesday, 12:17 p.m.,
the Mediterranean Sea
The Tomahawk is a cruise missile which can be fired from torpedo tubes or from specially constructed vertical launch tubes. There are four kinds of Tomahawk: the TASM or antiship missile; the TLAM-N or land-attack missile equipped with a nuclear warhead; the TLAM-C, a land-attack missile with a conventional warhead; and the TLAM-D, a land-attack missle equipped with low-yield bomblets.
After the twenty-five-foot-long Tomahawk has been launched via rocket booster, small wings snap from the sides and lock into place. The rocket shuts down within a few seconds of firing and the missile's turbofan engine kicks in. By then, the Tomahawk has attained its flying speed of over five hundred miles an hour. As it scoots low over the land or ocean, its guidance unit keeps it on target with input from a radar altimeter. Following a computerized flight path, the Tomahawk quickly reaches its pre-landfall waypoint. This is the site which enables the missile to spot and lock on its first navigation point--typically a hill, a building, or some other fixed structure. After that, the onboard Terrain Contour Matching system or TERCOM carries the Tomahawk from point to point, often through sharp turns, sharp ascents, or dizzying dives. Corroboration of the course is provided by the Digital Scene Matching electro-optical system, a small television camera which compares the actual visuals to those stored in the TERCOM's memory. If there is any discrepancy, such as a parked truck or new structure, the DSMAC and TERCOM will quickly determine whether the rest of the image is correct and that the missile is on-target. If not, it sends a signal home which can be answered with one of two commands: continue or abort.
The TERCOM data is prepared by the Defense Mapping Agency and then forwarded to a Theater Mission Planning Center. From there, it is transmitted via satellite uplink to the launch site. When previously unmapped regions are targeted, up-to-the-minute satellite imagery is employed by the DMA. Depending upon the accuracy of the mapping, the Tomahawk is precise enough to destroy a car-sized target thirteen hundred miles away.
Presidential Directive M-98-13 was received by the communications shack of the USS Pittsburgh at 12:17 p.m. local time. The encrypted order was sent digitally, via secure satellite uplink, and was quickly decoded and hand-carried to the submarine's Captain George Breen.
The task directive gave Captain Breen his mission, his target, and his abort code. One of the twenty-four Tomahawks his submarine was carrying was to be launched of 12:30 p.m. local time toward a target in Lebanon's Bekaa Valley. The precise coordinates were provided, backed up by the DMA TERCOM data for the missile itself. If the target were moved, the Tomahawk would switch to a fallback guidance program. The missile would search to the horizon for visual, microwave, electromagnetic, and other characteristics which in combination could only describe the target. It would then lock onto the object and destroy it. The only way to order the missile to self-destruct before reaching its target was if the captain received the abort code HARDPLACE.
Captain Breen signed the directive and passed it to Weapons Officer E.B. Ruthay. Stationed in the control room, he worked with Console Operator Danny Max to load the flight data into the Tomahawk's computer. After it was downloaded and checked, the USS Pittsburgh slowed to a speed of four knots. It rose to periscope depth. Captain Breen gave the order to launch the missile. The hydraulically operated doors of one of the submarine's twelve forward-located vertical launch system tubes was opened. The pressure cap used to protect the missile was ordered withdrawn. The Tomahawk was ready for firing.
Captain Breen was informed of the missile's status. After making sure that there were no hostile aircraft or surface ships within detection range, he ordered Ruthay