[Llarry]

In the post above I introduced the RIM-161 Standard missile SM-3 used for intercept of ballistic missiles. Here's the background and history of U.S. Navy air defense missiles...

The first Navy surface to air missile was the Terrier (RIM-2), which was first test-fired in the early 1950s. It was a large two-stage missile with a booster rocket that would fall away and send the missile with warhead and sustainer rocket to the target. Given that it was the 1950s there was a nuclear warhead version designed to take out massed formations of aircraft attacking the fleet, but the majority of missiles had conventional warheads. Given the large size of the missile, a sizeable warship (cruiser-size) was needed to accommodate the twin-arm launcher and missile magazine.

To allow smaller ships to have missile capability a version without the booster was introduced that could be carried by destroyers and frigates. This was the Tartar (RIM-24). The launchers were both single- and twin-arm.

The Terrier and Tartar got the nickname of the "Terrible Ts" as the reliability was poor, but over the years improved.

Although the appearance of the missile was nearly identical, the above two SAMs were succeeded from the 1960s by the long Standard-ER (extended range; RIM-67) and the shorter Standard-MR (RIM-66) missiles; performance and reliability were further improved. Missile range was often quoted as 20 miles for Terrier and 10 miles for Tartar; these have improved dramatically over the years.

Several aircraft carriers were built with twin-arm launchers for the RIM-24/66, but the missile magazines were bulky and the missiles were soon removed. While the carriers depended on accompanying surface combatants for air defense, a more compact solution that could be mounted on the carrier for last-ditch defense was desired. The solution was to adapt the Sparrow air to air missile for use abord ship in a compact launcher; the result was the Sea Sparrow (RIM-7), which became operational in 1969. The latest variants still serve in the fleet today.

Just to give you a sense of scale, a Terrier or RIM-67 weighed 3,000 lbs at launch, while a Tartar or RIM-66 weighed 1,300-plus and a Sea Sparrow was about 500 lbs.

An even more compact missile was ultimately developed and is now widely used in the fleet: The RAM (Rolling Airframe Missile; RIM-116) is truly a last-ditch solution with a launch weight of just 160+ lbs. and a range of just a few miles. It became operational in 1993.

All the above missiles require a separate radar and fire control systems; given that in the heat of battle there may be issues with that, a self-contained unit called SeaRAM was developed with its own radar and fire control; as long as it has electrical power it is functional.

Meanwhile, the Sea Sparrow was improved; the original missile was 8 inches in diameter. By increasing the diameter of the rocket motor to 10 inches, additional acceleration and range were obtained. This is the ESSM (Evolved Sea Sparrow Missile; RIM-162); it can be launched from the same launcher as the Sea Sparrow. This is now the longer-range defense option for aircraft carriers and can also be fitted to surface combatants.

The above-deck single- and twin-arm launchers were a perennial maintenance headache on surface combatants and in the 1980s an improved system was developed: Rather than a launcher for one or two missiles and a magazine storing reloads below decks, each missile had its own launch tube with a blast door above to provide protection, eliminating many moving parts and improving reliability. These vertical launching systems (VLSs) are now standard in U.S. and allied navies and the above-deck launchers have disappeared.

The Standard missile has been further developed into a series of ever more capable missiles. In 1998, the Standard-ER was introduced, but rather than the long booster of the 1950s, this missile had a short but larger diameter booster that increased range considerably.

The ultimate development of the Standard missile is the SM-3 (RIM-161) used to intercept ballistic missiles; this is covered in a previous post. The 10-mile range of the original Tartar has become 200+ miles in this latest iteration, despite the fact that the size and appearance of the missile is quite similar to its 1960s predecessor.

One additional brief note: If an attacking aircraft or missile manages somehow to survive the Standard missiles fired by escorting surface combatants and the ESSM fired by those ships or the carrier itself AND the RAM fired by those ships or the carrier itself, it still faces one final defense: The Phalanx close-in weapons system (CIWS) which uses a 20mm rotating-barrel cannon for targets within a mile or so. (The 20mm cannon fires a very heavy depleted-uranium 12.7mm bullet inside a jacket; the goal is to stop/break up the attacker.)