How Aegis shore defenses will protect the US from missile threats
Defense Secretary James Mattis told lawmakers that the emerging Aegis Ashore ballistic missile defense system, established for Poland and Romania, could also now possibly help protect U.S. Pacific theater assets and allies from possible Chinese or North Korean attacks.
"We are looking at Aegis Ashore to protect our Pacific areas," Mattis told the House Armed Services Committee, suggesting a fixed site could augment existing BMD-capable Navy ships on patrol in the region.
Aegis Ashore technology builds upon the success of Aegis missile defense at-sea by establishing land sites that can detect and destroy incoming enemy ballistic missile attacks. An Aegis Ashore site became operational in Romania in 2015, and another is slated to stand up in Poland sometime later this year. The system uses Aegis radar in tandem with SM-3 interceptor missiles to track and destroy ballistic missile attacks.
Adding a land-based Aegis BMD technology brings a potential range and target envelope advantage, as it could defend areas less reachable to Navy ships. While ship-fired Aegis BMD does have quite a range and is able to destroy approaching threats from beyond the earth's atmosphere, a land site could naturally, in some circumstances, preclude a need for Aegis BMD capable ships from needing to patrol certain areas at certain times.
Thus far, going back to the Pentagon's previously established European Phased Adaptive Approach Aegis Ashore has primarily been oriented toward protecting the European continent from potential future ballistic missile threats such as Russia and Iran, among others. Secretary Mattis is now suggesting the shore-based SM-3 interceptors could migrate to Aegis as a compliment to the existing Terminal High Altitude Area Defense (THAAD) weapon now protecting the region.
The prospect for Aegis Ashore in the Pacific emerged during a HASC hearing on the Pentagon's newly released Nuclear Posture Review when Guam Congresswoman Rep. Madeleine Bordallo asked Mattis about plans to protect assets based in Guam such as B-2, B-52 and B-1 bombers.
"Guam holds vital strategic bases to aid our defense, and in your strategy, you call for investment in layered missile defense," Bordallo said.
Bordallo's concern resonates alongside of the consistently discussed threat that North Korean short and intermediate range ballistic missiles pose to the region; it is often cited as a reason to hesitate about striking North Korea given the knowledge that the North would be expected to immediately fire its arsenal of missiles toward South Korea and Guam.
The Aegis Ashore Weapon System launched an SM-3 Block IB guided missile from the land-based Vertical Launch System during a Missile Defense Agency and U.S. Navy test from Kauai, Hawaii. (DoD photo by Chris Szkrybalo)
It was in response to this that Mattis raised the prospect of bringing Aegis Ashore to the Pacific to, along with THAAD and Navy Aegis BMD ships, provide the layered defense system Bordallo referred to.
Missile Defense Agency developers explain that the Aegis Ashore program, which has been successful thus far, is preparing to fire a longer-range and more advanced SM-3 IIA missile for the first time in coming months.
A follow on to the SM-3, the SM-3 IIA is a larger and more high-tech interceptor missile able to destroy threatening targets at longer ranges; the weapon, being developed as part of a cooperative arrangement between the U.S. Missile Defense Agency and Japan, is designed to work in tandem with Aegis radar systems to track and destroy approaching enemy missiles – by knocking them out of the sky.
Aegis radar works by sending electromagnetic "pings" into space to identify the location and trajectory of an approaching missile threat – and then works with an integrated fire control system to guide the SM-3 interceptor to its target, with the intent of destroying it or knocking it out of the sky.
At sea, integrated technologies and electronics on the ship, including fire control systems, link information from the Aegis radar with a ship's vertical launch tubes able to fire out SM-3 interceptor missiles.
In existence since 2004, Aegis BMD is now operating on 28 Navy ships and with a number of allied nations. U.S. allies with Aegis capability include the Japan Self Defense Forces, Spanish Navy, the South Korean Navy, the Royal Australian Navy, Italy, Denmark and others, MDA officials said.
Using various guidance technologies, the SM-3 flies up into space to destroy approaching ballistic missile threats. The SM-3 missile uses an enhanced two-color infrared seeker and an upgraded steering and propulsion capability, Raytheon weapons developers have told Warrior Maven. These technologies use short bursts of precision propulsion to direct the missile toward incoming targets, they added.
A Missile Defense Agency official told Warrior Maven that "the SM-3 Block IIA missile is a larger version of the SM-3 IB in terms of boosters and the kinetic warhead, which allows for increased operating time. The second and third stage boosters on the SM-IIA are 21" in diameter, allowing for longer flight times and engagements of threats higher in the exo-atmosphere."
The Pentagon is hoping to increase production quantities of the SM-3 IIA as well; they are waiting to see whether Congress succeeds in allocating additional funding for the missiles.
SM-3 IIA Technology
Now that it is being prepared for Aegis Ashore, it seems clear that a longer-range SM-3 IIA weapon could prove relevant in any defense against North Korean or Chinese ballistic missile attacks. The Missile Defense Agency and Raytheon have configured the emerging SM-3 IIA missile with a more "sensitive" seeker and software designed to accommodate new threat information.
Amy Cohen, SM-3 Program Director, told Warrior Maven in an interview a few weeks ago that the SM-3 IIA program is on track.
"We've also brought in some capability advancements into our kinetic warhead, so we now have higher sensitivity," Cohen explained.
By adding new software, industry developers create the technical framework necessary to upgrade or "reprogram" new threat information into the missile over time, Cohen explained.
"We can improve the performance through software algorithms. We are not only able to increase the threat space but bring in new threats as they emerge through software upgrades," Cohen added. "We work with the MDA to define how we're going to make improvements and what threats we want to incorporate."
The SM-3 IIA also incorporates sensor technology improvements designed to enable the missile to see or detect targets farther into space, developers explained.
The SM-3 is a kinetic energy warhead able to travel at more than 600 miles per hour; it carries no explosive, but instead relies on the sheer force of impact and collision to destroy an enemy target. While many details of the advanced seeker are not available, Cohen did say it includes infrared technology.
"We can see a threat that we are engaging much sooner. As soon as we open our eyes, we can see threats much earlier and we have the ability to track them. This helps us with how we need to maneuver the kinetic warhead to ensure that we have a kinetic engagement with the threats that we are flying against," Cohen added.
The Aegis ashore deckhouse in Romania was engineered with Aegis BMD Weapons System 5.0 -- an integrated suite of technologies which provide multi-mission signal processing capability, Lockheed officials said.
For instance, the multi-mode signal processor provides the ability to simultaneously track air and cruise missile threats as well as ballistic missile threats, officials added.