Finland is buying a hundred American RGM-84Q-4 Harpoon anti-ship missiles to replace the older RBS-15 anti-ship missiles on its four Hamina class corvettes and to equip four new corvettes. Most of the Harpoon missiles will equip coastal artillery units. RGM-84Q-4 is the latest version of Harpoon and has range of 248 kilometers and an all-weather radar homing guidance system and new, lighter but more lethal warhead. The 663 kg (1,460 pound) ship launched Harpoon has a 140 kg (308 pound) warhead and a range of 220 kilometers. It approaches the target low, at about 860 kilometers an hour. GPS gets the missile to the general vicinity of the target, then onboard radar takes over to identify and hit the target.
Harpoon has a successful combat experience going back two decades. Block II Harpoons have an INS backup guidance system along with several improvements to the software that make it useful against land targets as well as in coastal areas where there are a lot of islands and other geographical clutter. Each RGM-84Q-4 costs about $1.4 million. Finland is also buying over $20 million worth of maintenance, training and support for the Harpoons.
Finland is also buying 68 RIM-162 ESSM (Evolved Sea Sparrow Missiles) to provide its four new corvettes with anti-aircraft/missile capability. ESSM is a modified version of the standard Sea Sparrow shipboard anti-aircraft missile, which has been around since the late 1970s. Sea Sparrow was based on the 1950s era U.S. Air Force AIM-7 Sparrow radar guided air-to-air missile. That weapon, much modified and upgraded, is still in use. ESSM is basically a new missile, being different in shape and capabilities from the original Sparrow. ESSM can track and destroy high-speed anti-ship missiles and small, fast attack boats, as well as aircraft. ESSM is 3.7 meters (12 feet) long, has a diameter of 254mm, and weighs 280 kg (620 pounds). It carries a 39 kg (86 pound) blast fragmentation warhead and a range of 50 kilometers. Guidance is provided by the firing ship's radar, which directs the missile to the general area of the target. At that point the ESSM missile uses its own guidance system, which homes in on the ship's radar signals bouncing off the target. The land version will be able to use one of various ground based radars. The ESSM on ships is usually stored and fired from a MK25 Quad Pack canister, each holding four missiles. Each of these MK25s will fit into one VLS (Vertical Launch Systems) cell. Each ESSM costs about $500,000.