US Missile Defence Agency and Boeing have completed the construction of the second interceptor test silo for the ground-based midcourse defence (GMD) system at Vandenberg Air Force Base.

The GMD, an integral component of the global ballistic missile defence system, consists of radars, sensors, command-and-control facilities, communications terminals and a 20,000-mile fibre-optic communications network that links to the silo.

The new underground silo will provide additional test capability for the US Defence against long-range ballistic missile threats.

Boeing vice president and GMD programme director Norm Tew said that the second test silo to launch interceptors will enable quicker testing upgrades to the GMD, improving the MDA’s ability to stay ahead of evolving threats.

A silo needs to be refurbished after its hot-burning interceptor is fired, hence the two silos will allow one to support testing when the other is being refurbished.

The new silo can be configured for testing or tactical operations offering greater flexibility.

The air force base’s first test silo has served in tests since 2006 and will support future flight test operations.