Block 1A and Beyond
Written by Peter A. Buxbaum
Government/Industry team increases SM-3's lethality and
flexibility with an ambitious spiral development program.
FLEXIBILITY AND INTERCEPT OPTIONS
Sea-basing provides missile defense with inherent flexibility and multiple opportunities to intercept missiles in their ascent, midcourse and descent phases. The mobility of the ship also gives the operational commander the flexibility to respond to changing threat scenarios.
The first iteration of Standard Missile-3 (SM-3) has already been deployed to the Aegis ballistic missile defense system, with additional rollouts anticipated in short order. The SM-3 is compatible with the MK 41 vertical launching system deployed on many Navy vessels.
“The Aegis ballistic defense system is a development program of the Missile Defense Agency, but it is also a Navy field activity,” said Captain Randy Hendrickson, the Navy staff’s branch head for theater and missile defense. “Whenever the MDA puts a missile on a Navy ship, it’s our job to test it and to make sure it is integrated with our combat systems.”
“The Missile Defense Agency has made great progress in evolving the SM-3 architecture and delivering more robust capabilities to sea-based ballistic missile defense,” said Kevin Peppe, deputy of the naval weapons systems product line at Raytheon Missile Systems. Raytheon is the designer and builder of the SM-3.
SM-3 has been built on earlier standard missile versions and is itself being rolled out in a spiral development program. The phased rollout ensures that the Navy will be provided with missile advanced defense capabilities as they become available and that development is paced to counter emerging threats. Anticipated advances to SM-3 Block 1A, which has already been fielded, include changes in the design of the missile itself, as well as in its seeking and destroying capabilities.
The SM-3 is designed to work in concert with ship radar and remote BMDS sensors. Those sensors acquire and begin tracking ballistic missile threats as they rise above the horizon. The Aegis weapons system then calculates an engagement solution and commands the SM-3 to boost out of its launcher.
After booster burnout, a dual-thrust second-stage rocket motor and finally the third-stage rocket motor ignite, propelling the third stage out of the atmosphere. In-flight radio communications from the ship continue to guide the missile toward the predicted intercept point.
During third-stage flight, the missile nose cone is ejected, and the SM-3 kinetic warhead (KW) is exposed. Following third-stage burnout, the SM-3 KW searches and acquires the ballistic missile warhead with its long-wavelength imaging infrared seeker, then precisely maneuvers itself to enable the intercept.
U.S. Navy officers and crew have tested a variety of SM-3 engagement scenarios, including ascent and descent phase intercepts, aim point selection and guidance, and lethal aim point intercepts, all of which were performed under operationally realistic conditions. The test missiles have achieved a 90 percent hit ratio.
The SM-3 has a spiral upgrade path designed to counter the evolving ballistic missile threats. “Block 1A is in production and fielded today,” said Peppe. “In the course of the next 12 to 18 months, we will see Block 1B enter the field and eventually replace the Block 1A missiles.” Block 2 is still years away.
“Block 1A was built based on legacy systems with some obsolescent components removed after early testing,” Hendrickson said. “Block 1B will include a few new features and enhancements that will enable it to better home in on the target during the end game,” that stage in which the missile is zeroing in on its target. “Block 1B is well into design and development,” added Peppe.
The end game—in which the SM-3 finally homes into the precise anticipated location of the threat in order to make the kill—is the most difficult part of the missile defense concept of hitting a bullet with a bullet, noted Peppe. “It involves the ability of the missile seeker to be able to sense not only where the incoming threat is but to optically scan that threat in real time and with very fast closing rates to calculate where to maneuver to hit the right spot,” he said. “What we want to do is to destroy warheads. That might not be done with an improper placement of the kill vehicle.”
As the warhead closes in, it will identify the area on the target where it can achieve the greatest lethality and will shift its guidance aim point to ensure a lethal hit. The KW destroys its prey by releasing over 130 megajoules of kinetic energy, the equivalent of a 10-ton truck traveling at 600 miles per hour. Aiding in the precision hit will be the two-color, all-reflective infrared seeker, which will be incorporated in SM-3 Block IB. The advanced seeker enables longer-range acquisition and increased threat discrimination.
The infrared seeker, which will be equipped with Block 1B, allows tracking of the incoming missile throughout its flight, noted Hendrickson. “This represents a significant capability enhancement over the atmospheric radio frequency tracking provided in earlier versions of the standard missile,” he said. “The IR seeker will provide better divert and attitude control and better discrimination in the end game, which will allow the system to provide the last bit of guidance to ensure the kill vehicle collides with the incoming missile.”
BLOCK 2A TAKES FORM
Block 2A is slated to make an appearance around the middle of the next decade. “The idea is that we must keep pace with the threat,” said Peppe. “We are working to counter anticipated improvement to the ballistic threats, which make them harder to kill.”
Block 2A will see changes to the physical structure of the SM-3 while also making improvements to its sensor suite. “SM-3 Block 1 incorporated the booster and first-stage rocket motor of SM-2 Block 4,” Hendrickson noted.
That system featured a 21-inch booster riding on a 13-inch missile. The Block 2A iteration will have a booster and a missile both measuring 21 inches, so that the device will be distinguishable from its predecessor with the naked eye.
“Block 2A will also include improvements that make the missile more mobile at the end game,” said Peppe. “The missile will feature increased capabilities in terms of kinetics and in terms of range. It will also be more intelligent, in that it will be able to discern the right target to hit and will be able to distinguish the incoming threat from a decoy.” Block 2A is also distinguished by the fact that it is part of a larger co-development effort that is being undertaken by the U.S. Department of Defense with the Japanese Ministry of Defense. Japan is already currently buying Block 1A missiles from the United States, Hendrickson noted.
“Japan has some needs in terms of precision missile defense,” said Peppe. “The two governments have decided to co-develop Block 2A, which involves much more than co-production.”
Co-production essentially means dividing the work of providing components between two or more countries, according to Peppe. “In this case there is much more of an intimate collaboration in designing critical elements of the system,” he said. The result has been the development of government and industry development teams that work together on an equal basis.
“There is a seamless shuttling back and forth from the government side and the industrial side,” said Peppe. “We get all the cooperation and collaboration we need to make the program successful.” In the last two years, Peppe added, a sound government-to- government structure has been established in preparation of the design and development work.
Raytheon’s counterpart on the Japanese side is Mitsubishi Heavy Industries. “We are partnered with them,” said Peppe. “It is not the relationship of a prime contractor and a subcontractor. There is a co-equal relationship between Mitsubishi and Raytheon.”
That said, the emphasis of the work may fall on one company rather than the other. Peppe anticipates that Raytheon will be doing more of the sensor work while Mitsubishi is likely to be tackling propulsion issues to a greater extent.
Peppe anticipates continued opportunities for research and development work for future iterations of the SM-3. In the case of one ongoing project, Raytheon, Lockheed Martin and Northrop Grumman are working on an interceptor called the Stunner. “We’re trying to take all the things we’ve learned in working on missile intercepts and build an interceptor that can predict the target more readily and less expensively,” said Peppe.
Stunner is part of the David’s Sling weapons system, a terminal missile defense interceptor now under development by Raytheon Missile Systems and the missile division of Rafael Advanced Defense Systems Ltd., an Israeli concern, under the auspices of MDA. Stunner is being designed to counter short-range ballistic missiles, large caliber rockets, and cruise missiles and to be inserted into integrated air and missile defense systems.
The SM-3 missiles that are currently under development are also being considered for land-based missile defense systems, according to Peppe. “It is testimony to the fact that it is a wellproven system,” he said. “Our goal is that our interceptor will be able to marry up with any sensor suite and any command and control system that has been deployed or will be deployed.” Peppe believes a key future application of the SM-3 missile will be to protect key national security sites from ballistic missile threats. These could include not only military sites but cities under threat, or key pieces of national infrastructure, such as energy installations.
“I would not be surprised by a discussion and deployment of SM-3 missiles and its associated sensors and command and control system in critical places around the world,” said Peppe. “Industry has been a big partner with the Navy and the MDA,” said Hendrickson. “They are addressing and keeping pace with things our enemies are doing today as well as in trying to get in to their heads to anticipate what they will be doing in the future and making the necessary adjustments.”
“We believe that the Navy will continue to evolve the architecture it has in place,” said Peppe, “to continue to make improvements and modifications to interceptors, sensors, and command and control systems to counter threats that have yet to be determined.” ♦