September 28, 2005
Tactical Tomahawk: The Next Generation of Precision Strike
Able to change targets while flying and communicate with operators through satellite data streams, Tactical Tomahawk is the nation's most advanced precision weapons system. And APL is helping the Navy guide this next-generation asset to the fleet.
This year Tactical Tomahawk successfully completed its Operational Evaluation—the Navy's final assessment—paving the way for the Navy to replenish depleted Tomahawk inventories and giving it a faster-responding, more accurate, and lower-cost option for long-range precision strike.
Tactical Tomahawk offers launch platform mission planning, a loitering link. Known as the Tomahawk Strike Network (TSN), this communications link will allow Navy operators to redirect missiles to new targets in flight, thereby using them more efficiently.
For two decades, trusted by both government and industry as the "technical conscience" of the Tomahawk Cruise Missile program, APL has provided critical technical solutions to the program's toughest challenges.
The Tomahawk Weapons System consists of three segments: the missiles and associated components, mission planning and command and control facilities ashore and afloat, and weapons control systems aboard the launch platforms. Although each segment was developed separately, the Laboratory successfully integrated them into an operational system.
When the mission planning contractor needed a simplified navigation simulation, the Laboratory developed, tested, and delivered the simulation. By providing simulation management, APL reduced the number of required flight tests and lowered program costs by verifying system performance with accredited simulations. APL also chaired the board that validated each simulation and accredited the organizations that would execute them.
Like earlier versions of Tomahawk, Tactical Tomahawk is a long-range, precision weapon launched from surface ships and submarines. Following a preplanned route, it can travel hundreds of miles at subsonic speeds.
Dating back to Operation Desert Storm in 1991, Tomahawk has been used in nine engagements, with more than 1,800 missiles fired. APL assessments show that success exceeded expectations: no friendly forces were lost or captured, most targets were destroyed or damaged, and there was low collateral damage.
Still, the Navy needed a faster and less costly way to attack time-critical targets. In 1997, the Navy challenged the Tomahawk program office to "develop a capability for Tomahawk to react to time-sensitive, emerging, and relocatable targets." This capability would include launch platform mission planning, in-flight retargeting, and the ability to "loiter" over an area while waiting for a target. APL was asked to lead development of these concepts and played a significant role in helping the Tomahawk program office to accommodate these new requirements.
Building on its predecessors, Tactical Tomahawk features reduced alignment time, a better anti-jam Global Positioning System (GPS), a longer service life, steeper dive angles, improved weapon delivery accuracy, and two-way in-flight communications using ultra-high frequency (UHF) satellites. The missile can transmit health and status messages and send a battle damage indication message just before it hits the target.
APL led or participated on several government/contractor teams that developed various missile components. Among APL's contributions were guidance equations for the missile's terminal dive maneuver and proving the resistance of the missile's GPS system to jamming.
Planning, Command, and Control
Tomahawk missions are planned both on shore and aboard aircraft carriers. Using extensive terrain and threat databases, planners create overland routes to selected targets and distribute these missions to all Tomahawk ships and submarines.
The mission planning system has been upgraded to plan both single- and multiple-outcome missions; to plan, task, and coordinate strikes; and to monitor and control the missiles in flight. APL developed many of the algorithms and processes for the planning systems that predict the probability of each mission's success, and played a major role in developing the processes and procedures for providing precision aim-points to mission planners. The work included specifications and quality control for critical planning databases produced by the National Geospatial-Intelligence Agency.
APL also led the government/contractor team that developed details for implementing the satelite data link. Together, the Tactical Tomahawk missiles, Tomahawk strike controllers, and the Navy's UHF satellite control stations are called the Tomahawk Strike Network (TSN).
Weapons Control System
Aboard launch platforms, the Tomahawk weapons control system prepares and executes the launch by identifying the appropriate missile, applying power, transferring alignment and mission data, and firing the missile. During preparation, the operator establishes way-points to create the over-water portion of the route.
The Tactical Tomahawk Weapons Control System receives tasking and strike plans and can plan GPS-aided missions for the earlier Block III version of Tomahawk as well as the Tactical Tomahawk missiles. The system can monitor all missiles in flight and control the missiles that it launches. The Laboratory provided detailed software engineering to integrate new features —such as launch platform mission planning and strike monitoring and control—into legacy systems.
APL is also providing the rigorous systems engineering needed to adapt the weapons control system and its interfaces to other Navy systems to the new missile. And, using its detailed knowledge of Tomahawk's capabilities and limitations, APL has made major contributions to tactics and doctrine necessary for successful employment of Tomahawk. APL also publishes the Tomahawk Technical Description Document, the textbook used to train Tomahawk staff officers and shipboard operators.
With Tactical Tomahawk now going into production, three new efforts are under way:
- The missile's airframe is being strengthened to accommodate torpedo tube launch to allow the United Kingdom to purchase Tactical Tomahawks.
- The Navy is modifying four of its ballistic missile submarines to launch Tomahawks.
- Tactical Tomahawk will be launched from DD(X), the Navy's 21st century destroyer. APL has a systems engineering role for integrating Tomahawk weapons control capability into the DD(X) command and control system.
Tactical Tomahawk flight tests were divided into two phases: the Technical Evaluation (TECHEVAL) and the Operational Evaluation (OPEVAL). The TECHEVAL was preceded by a functional ground test and two missile flights by the prime contractor. APL led the successful ground test team—providing test planning, execution, and results analysis—and defined the test objectives for the two subsequent contractor tests, which were also successful. By this time, several organizations were monitoring the flight tests as members of the TSN.
Throughout the entire test period, APL served as TSN test coordinator for all participants, providing each with satellite channel information, conducting dry runs, and giving technical assistance when required.
The TECHEVAL of Tactical Tomahawk involved four missile tests, including two with live warheads. Again, APL participated in the test planning, execution, and data analysis. Preceding one of the tests, problems with GPS almanac data were discovered, but APL was able to quickly confirm a proposed fix and the program remained on schedule. All four tests were successful.
The OPEVAL tests brought the first flight failures; APL served on the failure review team that identified the problems. The contractor made the right design changes, and the OPEVAL was completed with three successful flights.
During both TECHEVAL and OPEVAL, the Navy wanted to test the end-to-end Tomahawk Weapons System, including use of the TSN with multiple missiles in the air, but the cost was prohibitive. So APL developed a way to simulate the communications of multiple Tactical Tomahawks in flight—a capability that met test objectives and helped to identify and resolve several TSN issues.
All Tactical Tomahawk flight tests were subject to a preflight review by an executive-level panel convened by the Program Executive Office managing the Tomahawk program. APL, as technical direction agent, is a standing member of this panel.