Table 1
In response to the evolving geopolitical environment, the National Missile Defense program has been elevated from a technology effort to a Deployment Readiness Program. A Joint Program Office has been established under the Ballistic Missile Defense Organization and given a charter to develop a National Missile Defense system for possible future deployment. The Department of Defense has also designated National Missile Defense as a Major Defense Acquisition Program (MDAP) to ensure that it receives an appropriate level of management attention and oversight.
The mission of the NMD system under development is to defend against an ICBM attack consisting of several missiles launched at the United States from a rogue nation or a small accidental launch, from China for example. The system development is to be completed within three years and an integrated system test conducted by the end of 1999 to demonstrate the system's capabilities. The decision to deploy this system will be deferred until after a successful demonstration and the validation of a rogue nation threat. If a decision to deploy were made in 2000, the system could achieve operational capability in another three years, i.e., by the end of 2003. This strategy is commonly referred to as the "3+3" program. If a decision to deploy is not made in 2000, the program will work to improve the NMD deployment readiness posture by advancing the technology of each element and adding new elements, all the while maintaining the capability to deploy the system within three years of a decision.
A National Missile Defense architecture needs systems called "elements" to perform a number of key functions during a ballistic missile defense engagement.
The functions performed by the elements in a typical ballistic missile defense engagement are as follows. First, an Early Warning Sensor element detects the launch of one or more ballistic missiles and forms initial estimates of the missiles' tracks and targets. These estimates are then passed to the Battle Management, Command, Control, and Communications System (BM/C3) element. This system notifies the Command Center of the launch and provides data supporting the time-critical decision on whether the launch is hostile. The BM/C3 element directs other Sensor elements to continue the tracking and threat identification function throughout the missile's trajectory. These elements provide data of two primary types: accurate tracking data to provide weapon engagement information; and detailed threat signature data to distinguish among warheads and other objects in the threat. The BM/C3 element processes these data and continually relays current information to the human-in-control. Under human control, the BM/C3 element provides specific threat and trajectory information to one or more ballistic missile defense Weapon elements and tasks the appropriate element to engage and destroy the threat warheads. The Sensor elements continue to provide improved observational data in support of ongoing engagements. Following each engagement, the Sensor elements observe the results of the engagement, providing "kill assessment" data with which to assess its success or failure.
The initial deployment BMDO is developing is being designed to defend all 50 states from a single, central United States site. It is being structured to defend effectively against small numbers of threatening warheads from rogue nations. The Ground Based interceptors and a Ground Based Radar will be located at Grand Forks, North Dakota, the single United States site permitted under the ABM Treaty. Space sensors are not likely to be available if this architecture is deployed by 2003, so the architecture includes the option to use forward-based radars, whose location would depend on the specific Third-World threat against which the system is deployed.
These elements are depicted as they might be deployed for a notional single-site architecture in Figure 1. Quantities and other deployment data for such a single-site deployment are shown in Table 1. The Early Warning satellites would detect the launch of one or more threat missiles and track their bright infrared plumes until booster burnout. They would pass an estimate of the threat trajectories via the Battle Management, Command, Control and Communications system to the command center, so that the decision maker can authorize the defense to engage the threat. The Early Warning Radars and any other forward based radars, if present, would gather tracking and threat assessment data to support commit of the interceptor and to provide guidance updates for the interceptor via the BM/C3 once it had been launched. Following weapon release authority, and upon command, one or more interceptors would be launched to engage the threat. Depending on the trajectory of the threat and the particulars of the defense deployment, the BM/C3 system would process the Ground Based Radar and the other radar systems data and provide further threat data to the interceptor during flight to support discrimination of warheads from penetration aids and for providing better interceptor guidance against the targets. As the interceptor approached the target, it would acquire the target objects via their infrared signatures with its on-board sensor, select a target from external and internal data, and be guided to a direct high-speed collision by its own computers and propulsion systems. The radars would continue to take data throughout the defense engagement in order to perform kill assessment. For some deployments and threats, there may be sufficient battle space to allow time for multiple waves of interceptors.
The NMD Systems Engineer, along with the Element engineering effort, plays a crucial role in providing the necessary integration and orderly development of an NMD System which meets the user's requirements. The NMD Systems Engineer must ensure the optimum system is developed which meets all requirements and provides the proper balance of system performance, life cycle cost, development schedule, and risk. Much of the technology that makes up the individual elements of the NMD program is mature. The largest challenge is the integration of all the elements as a system. This challenge is being worked aggressively and it is at the centerpiece of the 3+3 strategy. The Systems Engineering and Integration contractor is on track for a Systems Requirements Review (SRR) in 1996. Results from this review could result in modifications to the NMD Architecture and a rebalancing of the element requirements to meet the system performance thresholds. Such modifications, if required, could cause a cost increase and a possible schedule delay.
The development program that will be executed over the next three years will be compliant with the ABM Treaty. The system components that are ultimately fielded, should a deployment decision be made after three years, might comply with the current treaty, or might require modification of the Treaty, depending on what the threat situation required.
This system would provide excellent protection of the US for small numbers of simple threats (e.g., a few warheads from a rogue nation). It would also have some capability against a small accidental launch, from China for example. However, if the number of threats or the complexity of the threats increases then this basic system is likely to provide poor protection of the US. This poor protection is due partly to a lack of sufficient discrimination capability against complex threats, which will cause the interceptor inventory to be depleted by shooting at warhead decoys, allowing some real warheads to penetrate the defense. This deficiency could be mitigated when the Space and Missile Tracking System is introduced.
The system is not designed to protect against an unauthorized launch which might contain a large number of warheads (e.g., a full load of warheads from a Russian SSBN).
The estimated costs to develop, produce and deploy a notional single-site system as described above are shown in Table 2. Costs for development alone would be about $2.5 billion, for a total program cost of about $10 billion to deploy. Since the NMD program has just been designated a MDAP and is still in the process of developing the actual architecture for an NMD system there is a significant uncertainty associated with the costs shown in Table 2. For example, the actual booster selected for the NMD interceptor and the type and quantity of forward-based early warning radars, both which will have significant impact on the total system costs, have yet to be determined. A better estimate of the actual costs will be available by the end of the year.
To perform the functions described above, BMDO is developing, testing, and integrating the five major components listed on Table 1. The following paragraphs describe their individual functions and status.
The Ground Based Interceptor (GBI) and its associated components provide the "muscle" of the NMD system. Its mission is to engage high speed ballistic missile warheads in the midcourse (exo-atmospheric) phase of their trajectories and destroy them by force of impact. The Ground Based Interceptor consists of:
The Ground Based Interceptor launches on a commit message from the Battle Management, Command, Control and Communications element and flies towards the target's predicted location. Aided by one or more in-flight target updates, the motor kill vehicle acquires the target cluster using on-board sensors. It then uses on-board target selection algorithms or a target object map obtained from the sensor systems in the architecture to determine which object is the proper target. The GBI adjusts its ballistic trajectory to collide with the target. Both the interceptor and the target are demolished in the collision.
The Exoatmosphefic Kill Vehicle (EKV) is the intercept component of the Ground Based Interceptor. The EKV has its own sensors, propulsion, communications, guidance, and computing, with the following functions:
The major EKV component is a multiple-waveband infrared seeker which allows the EKV to acquire and track targets. The seeker consists of a focal plane array(s) and a cryogenic cooling assembly at the end of an optical telescope. The seeker is supported by processing hardware and software to support target acquisition, tracking, and discrimination.
Currently, the two EKV contractors utilizing two different sensor approaches are integrating sensor hardware in preparation for two sensor flight experiments. These experiments will demonstrate for the first time that our EKV sensors can operate in the flight environment. The data collected by the sensors will be transmitted to the ground and used after the flight to validate discrimination software and define any changes required.
The EKV contractors have also begun to procure kill-vehicle hardware for intercept flights scheduled for FY98. As the components arrive from the manufacturers, they will be integrated into systems and tested. Current plans include hardware-in-the-loop (HWIL) testing of the seekers and electronics, cold chamber testing and calibration of the seekers, and strap-down testing of the Divert and Attitude Control System. The assembled EKVs will be integrated with the Payload Launch Vehicle (PLV), a test surrogate for a dedicated booster. Additional HWIL tests will be conducted prior to flight testing to ensure that the air vehicle (EKV integrated with booster) will perform as intended. A down selection between the contractors is scheduled for FY1998 although it is also possible that both EKV concepts will be retained past that time.
The Ground Based Interceptor program will develop a new booster or modify an existing booster which can satisfy National Missile Defense coverage and time line requirements. To achieve 50-state coverage from a single central-United States interceptor site, interceptor velocities of at least 7.2 km/sec must be achieved. Until such a booster has been developed, Ground Based Interceptor tests are being supported by a Payload Launch Vehicle with significantly less boost velocity. When the full-capability booster has been tested to ensure proper operation and payload deployment, it will replace the Payload Launch Vehicle.
The Ground Based Interceptor booster will launch the EKV toward an intercept point in space estimated from available sensor data at the time of launch. While on the ground, the interceptor will be housed in a launcher, with its associated built-in test equipment and environmental support equipment. In order to increase reliability and reduce life cycle costs, the Ground Based Interceptor is designed to remain in a dormant state until a ballistic missile attack occurs.
There are three candidate booster approaches being considered:
Initiation of the decision and development of dedicated Ground Based Interceptor booster and launch equipment has been deferred until FY98. The National Missile Defense Joint Program Office will issue one or more requests for information for GBI element integration and/or booster development.
Until the dedicated booster is available, flight tests are being conducted using the Payload Launch Vehicle. The PLV consists of the second and third stages of retired Minuteman II boosters, modified as necessary to function as first and second stages. PLV performance is adequate for testing, but is insufficient for single-site coverage of all 50 states.
The Command and Launch Equipment consists of the hardware and software for BM/C3 interface, human-in-control oversight, interceptor storage (silos), launch and readiness functions. For a deployed system, Pecuilar Support Equipment such as test equipment, specialized software support, and transportation equipment will also be acquired to fully support the integrated logistics support functions.
As a primary fire control sensor for the National Missile Defense, the Ground Based Radar (GBR) would perform surveillance, acquisition, track, discrimination, fire control support, and kill assessment. Before the launch of an interceptor, the radar would search for threat objects, either autonomously or in response to information from other sensors on where to look. After acquiring one or more threat objects, the radar would track them estimate their trajectory parameters, and, based on threat-object signatures, attempt to classify them into categories such as "warheads" or "decoys." When the available information becomes sufficient, interceptors would be launched. During interceptor flight, the radar would continue to track the target to obtain improved target-trajectory and target-signature data. These data would be used to redirect the interceptor prior to its intercept attempt. Following the engagement, the radar would continue to collect data for assessing the intercept and the destruction of the target.
The National Missile Defense Ground Based Radar will be a phased array X-band radar with a radiating surface about 12 m in diameter. In its full-power configuration, it will have an acquisition range of 4,000 km or more against typical warheads. The radar will be built with a degree of hardening against nuclear effects, particularly against high-altitude electromagnetic pulse. Environmental conditions, including snow and ice and other natural or manmade environments unique to the deployment locale, will also affect the design of the radar. The prototype version designed for use in the testing program will have reduced range (2000 km or more) and reduced levels of nuclear effects hardening. The prototype radar can be modified if needed to give it objective-level performance.
The National Missile Defense Ground Based Radar Prototype is being procured through a "Family of Radars" acquisition approach that emphasizes commonality of hardware and software components to satisfy both theater-defense and national-defense radar requirements. Significant cost savings will result from this approach. The contract for the prototype ground based radar was executed in the first quarter of FY 96. The program builds on the ongoing development of the theater version of the ground based radar. It includes some aspects specific to the national missile defense radar: development of computer software for operating the radar and evaluating its signals; simulations that test the hardware and software together; and support of integration testing with the other National Missile Defense elements. The prototype radar will be emplaced at the National Missile Defense system test range at Kwajalein atoll in the Pacific in time for use in radar tests and the Integrated System Test in 1999.
Upgrades to America's Early Warning Radar network will provide existing forward-based attack warning system the capability to augment the operation of a National Missile Defense system. The specific advantage of utilizing upgraded early warning radars in the National Missile Defense architecture is that they can be modified on a very short schedule, and the cost of modifying these existing radars is significantly less than the cost of building and deploying new radars.
The Upgraded Early Warning Radars (UEWRs) will detect, track, and count the individual objects in a ballistic missile attack early in its trajectory. Their data will extend the detection capability of the ground based radars, by telling them accurately where to look; and the data will improve the performance of the ground based interceptors by permitting them to be launched early and to operate in a larger region of space. The increased battle space will support earlier intercept opportunities and, potentially, more intercept attempts per attacking warhead.
America's early warning radars are large, fixed, phased array surveillance radars used to detect and track ballistic missiles directed into the United States. The Upgraded Early Warning Radars operate by continually scanning the horizon in the direction from which attacks would come, although an alert from the Early Warning Satellite systems would improve their performance.
In their current configurations, these radars can detect and develop approximate impact-location data for objects associated with a missile launch, such as the last missile stage. This information is insufficient for use by a ballistic missile defense system, for two reasons: it does not track each missile long enough before returning to the search mode, and it does not permit the derivation of sufficiently accurate trajectory parameters to support intercepts. Upgrades in the system's software, and modest changes to the hardware, are needed to address these shortfalls and to make the data so obtained, available to the National Missile Defense Battle Management, Command, Control and Communications system.
A program is about to begin to prepare and demonstrate the needed upgrades to the existing early warning radars. Depending on the anticipated threat (east coast or west coast) at the time of a defense deployment decision, the appropriate BMEWS and/or PAVE PAWS radars will be upgraded for inclusion in the National Missile Defense architecture. If needed, other existing forward-based radars (such as Cobra Dane or HAVE STARE) could also be used to support National Missile Defense.
Significant risks are involved in the UEWR program. The radars are old, and spare parts are difficult to obtain. Their long term availability is by no means assured. These radars are costly to operate and maintain. A viable operations and maintenance program will have to be agreed to if these systems are to remain part of the architecture. Their removal would increase risk and reduce system performance.
Forward basing of a ground based radar places the radar where it can obtain accurate data from early parts of an ICBM's trajectory. The advanced technology associated with X-band radars provides high angular resolution, thereby permitting effective performance against closely spaced threat objects. Together these radar attributes provide for early and accurate target-tracking and signature data, permitting earlier launch of defense interceptors and a greater battle space within which they can operate. The overall defense performance is thereby maximized.
Through the (BM/C3) element, the Commander in Chief of the North America Air Defense Command would control and operate the system, and the elements will function together as an integrated system.
The Battle Management, Command, Control and Communications element is the "brains" of the National Missile Defense system. It has four main functions:
If it is determined by the Command Authority that a ballistic missile attack upon the United States is in progress, available space-based and ground-based surveillance and warning system assets would be queried for early track correlation data and impact point prediction. Under human direction, readiness postures would be upgraded to ensure the smooth transition of National Issue Defense assets from peacetime to wartime operating modes; and automated BM/C3 decision aid software would develop, from a range of predetermined response options, a battle plan that fully describes the Commander's operational strategy.
The operational battle plan developed would include sets of operating thresholds and strategies that control the selected National Missile Defense weapons, sensors and communications. The BM/C3 element's engagement planning software would apply these rules to the threat data from the sensors and would generate plans for aiming and using the sensors, weapons, and communications links. During the battle these plans would be adjusted as new information becomes available and as the early engagements take place.
The nature of the BM/C3 operational plan requires that the human commander monitor and evaluate the threat and the National Missile Defense system's performance. The BM/C3 system will provide the human in control with the capability to change the operational plan in real time to improve performance by adjusting his/her use of National Missile Defense resources.
The Battle Management, Command, Control and Communications element supports the user with extensive decision support systems, displays, and situation awareness information. It correlates the best available intelligence information, current National Missile Defense system status, and data from all sensors and sensor systems. In this way, it supplies the means to plan, select, and adjust rnissions and courses of action; and it provides the vehicle to disseminate Weapons Release and other Command decisions to the National Missile Defense system elements.
The communications component of the Battle Management, Command, Control and Communications element has two sub-components:
An evolutionary development approach based on a "build-a-little, test-a-little" philosophy has been adopted for the Battle Management, Command, Control and Communications element. This approach is appropriate for systems with heavy user interfaces because such systems require significant user involvement and feedback during requirements definition and in the implementation phase. This evolutionary approach capitalizes on current technology thereby reducing cost, schedule, and performance risks to the BM/C3 element. Furthermore, this approach will leverage off existing BMDO and Service resources and utilize proven Commercial-Off-The-Shelf (COTS) and Government-Off-The-Shelf (GOTS) software wherever possible.
In FY1995 BMDO awarded a Battle Management, Command, Control and Communications / System Engineering and Integration Contract for the implementation of BM/C3. The contractor has defined the BM/C3 element in terms of its critical performance requirements and key test parameters.
In addition to the elements being developed by BMDO, future NMD systems will significantly be enhanced by the sensing capability of the Space and Missile Tracking System (SMTS) which is being developed by the Air Force as part of the Space-based Infrared System (SBIRS). SMTS is allocated those mission requirements that are best met by a low-altitude system with long-wavelength infrared sensors, primarily the ballistic missile defense mission. The unique orbit and sensors on SMTS will also provide valuable technical intelligence and battle-space characterization data.
In support of defense of the United States against ballistic missile attack, SMTS would support the maximum possible defended area from whatever configuration of ground-based interceptor sites is available at the time of the attack. The SMTS constellation of sensors and satellites will acquire and track ballistic missiles throughout their trajectories. Unlike the DSP and SBIRS high satellites, SMTS will be able to continue tracking the warheads after the missile booster stages all burn out and the warheads are deployed. This information provides the earliest possible trajectory estimate of sufficient quality to launch interceptors for a midcourse intercept. By providing this over-the-horizon precision tracking data to the NMD system, the interceptors can be fired before the missiles come within range of the ground based radars at the defense sites. This maximization of their battle space:
Not only is it beneficial to get the interceptors in flight as early as possible, but once in flight, the interceptors must be supported with tracking updates and identification information on the correct target. The lethal ballistic rnissile warheads must be discriminated from associated debris, deployment hardware, and penetration aids, based on their emission and/or radar-reflection properties. The sensors on SMTS provide discrimination data that complement the radar data; together, they can determine optimally which objects are threatening and which can be ignored. Because SMTS uses the same kind of sensing that interceptors use, the information it provides to the NMD system is less ambiguous than that provided by radars alone, and improved performance is thereby offered against threat decoys.
Each SMTS satellite will carry a suite of passive sensors that will provide surveillance,
tracking, and discrimination data, including short-, medium-, and long-wavelength infrared
sensors, which detect objects by their heat emissions, and visible light sensors that use scattered
sunlight. These sensors, which can be instructed to look in different directions independently of
each other, will provide global (below-the-horizon and above-the-horizon) coverage of ballistic
missiles in their boost, post-boost, and midcourse phases. SMTS can detect and track objects at
very long distances by observing them against the cold background of space.
Table 1
