Boeing completes silo increase for Ground Based Midcourse Defense

The US Ground Based Midcourse Defense System at Fort Greely, Alaska now has 20 new missile silos as part of an upgrade to the site led by Boeing, according to an article originally published by Defense News on 4th March.  

The US base at Fort Greely originally held 40 silos for the Ground Based Interceptor (GBI) missiles, this has now been increased to 60 silos distributed across four missile fields, however, the new silos are yet to be filled. An infographic on the Boeing website states that the company was expecting to have 64 interceptors deployed by 2023, indicating that the programme is behind schedule. 

The Ground Based Midcourse Defense System is designed to intercept inter-continental ballistic missiles (ICBMs) fired from North Korea or Iran. It is generally assumed that the system is not intended to, or capable of intercepting large complex strikes that would likely come from China or Russia. 

As a system, it consists of a variety of sensors including large ground-based radar arrays like the AN/FPS-108 Cobra Dane located at Eareckson Air Station on the island of Shemya, Alaska or the AN/FPS-126 Upgraded Early Warning Radar in the UK at RAF Fylingdales. They are supported by space-based detection systems that are focused on the infrared spectrum and hope to detect the significant heat generated by a missile launch, as well as Sea-based X-Band Radar-1; A unique radar housed on a decommissioned oil rig that is designed to provide high-resolution images of incoming threats so that the Ground Based Midcourse Defense System and its interceptors can discriminate between targets and debris. 

Various other air defence assets tie into the system, like the Aegis systems on board US ships and the radars used by Patriot and THAAD batteries. This is designed to provide as much warning as possible of a missile launch so that several interceptors can be launched and meet the ICBM in the mid-course of their flight, when interception is most likely. 

Calibre comment

President Trump initiated expansion of the Ground Based Midcourse Defense System during his first term as president and announced a new project that he terms the Golden Dome during the first week of his second presidency. Golden Dome aims to extend protection against ICBMs to all of America, in an joint session of Congress on the 4th March, he said he was asking Congress to, “fund a state-of-the-art golden dome missile defence shield to protect our homeland…Ronald Reagan wanted to do it long ago, but the technology just wasn’t there…but now we have the technology and it’s incredible. Other places have it, Israel has it, and the United States should have it too,” he said. 

However, the principle of providing ICBM defence over such a large area is a contentious one. The US is estimated to have spent $53 billion on the Ground Based Midcourse Defense System by 2020, according to a Government Accountability Office report, with a further $5 billion scheduled for the following five years. With that investment, the system has a patchy record of interceptions during tests and there have been issues with reliability in the design of the interceptors. However, the Missile Defense Agency (MDA) is working on a next generation interceptor designed to improve the probability of a successful intercept against multiple re-entry vehicles. The MDA originally envisaged buying 20 of the new missiles for the new silos at Fort Greely, and 11 for test flights. The cost of this procurement alone was estimated at $18 billion in 2021.