Mark 54 MAKO Lightweight Torpedo

The Mark 54 Lightweight Hybrid Torpedo (LHT) is a standard 12.75 inch (324 mm) antisubmarine warfare (ASW) torpedo used by the United States Navy.

Development
The Mark 54 was co-developed by Raytheon Integrated Defense Systems and the U.S. Navy under the U.S. Navy's Lightweight Hybrid Torpedo program in response to perceived problems with the extant Mark 50 and Mark 46 torpedoes.

The Mk 50, having been developed to counter very high performance nuclear submarines such as the Soviet Alfa class, was seen as too expensive to use against relatively slow conventional submarines.

The older Mk 46, designed for open-ocean use, performed poorly in the littoral areas, where the Navy envisioned itself likely to operate in the future.

The Mk 54 was created by combining the homing and warhead portions of the Mk 50 and the propulsion unit of the Mk 46, improved for better performance in shallow water, and with the addition of commercial off-the-shelf (COTS) technology to further reduce costs. It shares a lot of the software and computer hardware of the Mk48 ADCAP heavy torpedo, based around a custom PowerPC 603e chip.

Developmental testing began in July, 1999, and a successful critical design review was completed in November, 1999.

In April 2003, Raytheon was awarded a sole source contract for the production of the Mk 54. Full rate production began in October, 2004. In March 2010 the Fifth Fleet requested improvements in the Mk 54's performance against diesel-electric submarines via an Urgent Operational Need Statement (UONS). This led to a software Block Upgrade (BUG) program which began testing in August 2011 and which continues, having been criticised by the DOT&E for using unrealistic proxies for threat submarines.

The Mk 54 can be fired from surface ships via the Mark 32 surface vessel torpedo tubes or the vertical launch anti-submarine rocket (ASROC) systems, and also from most ASW aircraft, although they are slightly different lengths and weights. The P-8 Poseidon uses the High-Altitude Anti-Submarine Warfare Weapons Capability (HAAWWC) GPS-guided parachute kit to drop torpedoes from high altitude.

Users
The Mark 54 is carried by the U.S. Navy and the Royal Australian Navy. In October 2010, Australia ordered 200 more torpedoes. In June 2011, it was reported that India might buy 32 Mk 54 All-Up-Round Lightweight Torpedoes and associated equipment, parts, training and logistical support for an estimated cost of $86 million through U.S. government's Foreign Military Sales program.