Watch as HMS Astute fires Tomahawk missiles as part of a test firing exercise.
Footage shows the Tomahawk weapons, which launched from HMS Astute at up to 550 miles per hour (885kph) across the Gulf of Mexico.
The Tomahawk is a long-range, all-weather, subsonic cruise missile named after the Native American axe.
Introduced by McDonnell Douglas in the 1970s, it was initially designed as a medium to long-range, low-altitude missile that could be launched from a surface platform.
It has been improved several times, and due to corporate divestitures and acquisitions, is now made by Raytheon. Some Tomahawks were also manufactured by General Dynamics (now Boeing Defense, Space & Security).
In 1995 the US agreed to sell 65 Tomahawks to the UK for torpedo-launch from her nuclear attack submarines. The first missiles were acquired and test-fired in November 1998; all Royal Navy fleet submarines are now Tomahawk capable, including the new Astute class.
The Kosovo War in 1999 saw the Swiftsure-class HMS Splendid become the first British submarine to fire the Tomahawk in combat. It has been reported that seventeen of the twenty Tomahawks fired by the British during that conflict hit their targets accurately; the UK subsequently bought 20 more Block III to replenish stocks.
The Royal Navy has since fired Tomahawks during the 2000s Afghanistan War, in Operation Telic as the British contribution to the 2003 Iraq War, and during Operation Ellamy in Libya in 2011.