With the demise of its big-gun cruiser and battleship fleet in the 1950s, the U.S. Navy looked for a replacement weapon for providing ship-to-shore fire support for landing troops. The LFSW (Landing Force Support Weapon) requirement of August 1961 called for a non-nuclear missile to be used against unprotected troops and unarmoured vehicles. The requirement called for missiles with ranges up to 55 km (30 nm) for beach assaults, and ultimately up to 370 km (200 nm) for long-range fire support. The efficiency of the LFSW against the intended targets was to be at least as good as guns and unguided rockets.
The Applied Physics Laboratory (APL), which had also developed the U.S. Navy's surface-to-air missiles, studied numerous types of warheads, missile sizes, and guidance systems to determine the best design to fulfill the requirements. All-inertial guidance was potentially accurate, but would always suffer from errors in the determination of the positions of the target and the launching ship. Electro-optical (TV) guidance, then a new and promising option for missile homing, was impractical, because the intended targets did not usually present sufficient optical contrast. APL eventually decided for a simple and inexpensive inertial navigation system for midcourse guidance, with terminal accuracy provided by a missile tracking beacon pointed at the target by the forward troops. APL's design was named Taurus, and the designation ZRGM-59A was allocated in June 1963.
By 1964, the planned characteristics of the ZRGM-59A had been established in some detail. The Taurus was to fit on existing Terrier launchers, have a range between 31 km (17 nm) and 93 km (50 nm), and carry a 450 kg (1000 lb) warhead. The CEP of the missile was expected to be 190 m (210 yds) with inertial-only guidance, and 27 m (30 yds) with the forward homing beacon system. The Taurus design featured a Terrier-sized solid-fueled rocket booster, and an unpowered tail-controlled missile.
Initial tests of the inertial guidance system aboard U.S. Army MGM-29 Sergeant missiles were planned for early 1965. However, Taurus was effectively cancelled that year, with no hardware having been built. A few other proposals were made for an LFSW, including a naval version of the Army's MGM-52 Lance, but these came to nothing. The U.S. Navy did not have any long-range shipborne tactical ground attack missiles until the introduction of the conventionally-armed versions of the RGM-109 Tomahawk cruise missile.
Specifications
Except for the range and warhead data given in the main text, I have no data about the physical characteristics of the planned ZRGM-59A missile.
Main Sources
[1] Norman Friedman: "US Naval Weapons", Conway Maritime Press, 1983
