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Iowa-class battleship

The Iowa class was a class of six fast battleships ordered by the United States Navy in 1939 and 1940. They were initially intended to intercept fast capital ships such as the Japanese Kongō-class battlecruiser and serve as the "fast wing" of the U.S. battle line. The Iowa class was designed to meet the Second London Naval Treaty's "escalator clause" limit of 45000 LT standard displacement. Beginning in August 1942, four vessels, USS Iowa (BB-61), USS New Jersey (BB-62), USS Missouri (BB-63), and USS Wisconsin (BB-64), were completed; two more, USS Illinois (BB-65) and USS Kentucky (BB-66), were laid down but canceled in 1945 and 1958, respectively, before completion, and both hulls were scrapped in 1958–1959.

The four Iowa-class ships were the last battleships commissioned in the U.S. Navy. All older U.S. battleships were decommissioned by 1947 and stricken from the Naval Vessel Register (NVR) by 1963. Between the mid-1940s and the early 1990s, the Iowa-class battleships fought in four major U.S. wars. In the Pacific Theater of World War II, they served primarily as fast escorts for Essex-class aircraft carriers of the Fast Carrier Task Force and also shelled Japanese positions. During the Korean War, the battleships provided naval gunfire support (NGFS) for United Nations forces, and in 1968, New Jersey shelled Viet Cong and Vietnam People's Army forces in the Vietnam War. All four were reactivated and modernized at the direction of the United States Congress in 1981, and armed with missiles during the 1980s, as part of the 600-ship Navy initiative. During Operation Desert Storm in 1991, Missouri and Wisconsin fired missiles and 16 in guns at Iraqi targets.

Costly to maintain, the battleships were decommissioned during the post-Cold War drawdown in the early 1990s. All four were initially removed from the Naval Vessel Register, but the United States Congress compelled the Navy to reinstate two of them on the grounds that existing shore bombardment capability would be inadequate for amphibious operations. This resulted in a lengthy debate over whether battleships should have a role in the modern navy. Ultimately, all four ships were stricken from the Naval Vessel Register and released for donation to non-profit organizations. With the transfer of Iowa in 2012, all four are museum ships part of non-profit maritime museums across the US.

Background
The vessels that eventually became the Iowa-class battleships were born from the U.S. Navy's War Plan Orange, a Pacific war plan against Japan. War planners anticipated that the U.S. fleet would engage and advance in the Central Pacific, with a long line of communication and logistics that would be vulnerable to high-speed Japanese cruisers and capital ships. The chief concern was that the U.S. Navy's traditional 21-knot battle line of "Standard-type" battleships would be too slow to force these Japanese task forces into battle, while faster aircraft carriers and their cruiser escorts would be outmatched by the Japanese Kongō-class battlecruiser battlecruisers, which had been upgraded in the 1930s to fast battleships. As a result, the U.S. Navy envisioned a fast detachment of the battle line that could bring the Japanese fleet into battle. Even the new standard battle line speed of 27 knots, as the preceding North Carolina-class battleship and South Dakota-class battleship (1939) battleships were designed for, was not considered enough and during their development processes, designs that could achieve over 30 knots in order to counter the threat of fast "big gun" ships were seriously considered. At the same time, a special strike force consisting of fast battleships operating alongside carriers and destroyers was being envisaged; such a force could operate independently in advance areas and act as scouts. This concept eventually evolved into the Fast Carrier Task Force, though initially the carriers were believed to be subordinate to the battleship.

Another factor was the "escalator clause" of the Second London Naval Treaty, which reverted the gun caliber limit from 14 in to 16 in. Japan had refused to sign the treaty and in particular refused to accept the 14-inch gun caliber limit or the 5:5:3 ratio of warship tonnage limits for Britain, the United States, and Japan, respectively. This resulted in the three treaty powers, the United States, Britain, and France, invoking the caliber escalator clause after April 1937. Circulation of intelligence evidence in November 1937 of Japanese capital ships violating naval treaties caused the treaty powers to expand the escalator clause in June 1938, which amended the standard displacement limit of battleships from 35000 LT to 45000 LT.

Early studies
Work on what would eventually become the Iowa-class battleship began on the first studies in early 1938, at the direction of Admiral Thomas C. Hart, head of the General Board, following the planned invocation of the "escalator clause" that would permit maximum standard capital ship displacement of 45000 LT. Using the additional 10000 LT over previous designs, the studies included schemes for 27 knot "slow" battleships that increased armament and protection as well as "fast" battleships capable of 33 knot or more. One of the "slow" designs was an expanded South Dakota class carrying either twelve 16-inch/45 caliber Mark 6 guns or nine 18 in/48 guns and with more armor and a power plant large enough to drive the larger ship through the water at the same 27-knot maximum speed as the South Dakotas. While the "fast" studies would result in the Iowa class, the "slow" design studies would eventually settle on twelve 16-inch guns and evolve into the design for the 60500 LT Montana-class battleship after all treaty restrictions were removed following the start of World War II. Priority was given to the "fast" design in order to counter and defeat Japan's 30 knot Kongō-class fast battleships, whose higher speed advantage over existing U.S. battleships might let them "penetrate U.S. cruisers, thereby making it 'open season' on U.S. supply ships", and then overwhelm the Japanese battle line was therefore a major driving force in setting the design criteria for the new ships, as was the restricting width of the Panama Canal.

For "fast" battleships, one such design, pursued by the Design Division section of the Bureau of Construction and Repair, was a "cruiser-killer". Beginning on 17 January 1938, under Captain A.J. Chantry, the group drew up plans for ships with twelve 16-inch and twenty 5 in guns, Panamax capability but otherwise unlimited displacement, a top speed of 35 kn and a range of 20000 nmi when traveling at the more economical speed of 15 kn. Their plan fulfilled these requirements with a ship of 50940 LT standard displacement, but Chantry believed that more could be done if the ship were to be this large; with a displacement greater than that of most battleships, its armor would have protected it only against the 8 in weapons carried by heavy cruisers.

Three improved plans – "A", "B", and "C" – were designed at the end of January. An increase in draft, vast additions to the armor, and the substitution of twelve 6 in guns in the secondary battery were common among the three designs. "A" was the largest, at 59060 LT standard, and was the only one to still carry the twelve 16-inch guns in four triple turrets (3-gun turrets according to US Navy). It required 277000 shp to make 32.5 knot. "B" was the smallest at 52707 LT standard; like "A" it had a top speed of 32.5 knots, but "B" only required 225000 shp to make this speed. It also carried only nine 16-inch guns, in three triple turrets. "C" was similar but added 75000 shp (for a total of 300000 shp) to meet the original requirement of 35 knot. The weight required for this and a longer belt – 512 ft, compared with 496 ft for "B" – meant that the ship was 55771 LT standard.

Design history
In March 1938, the General Board followed the recommendations of the Battleship Design Advisory Board, which was composed of the naval architect William Francis Gibbs, William Hovgaard (then president of New York Shipbuilding), John Metten, Joseph W. Powell, and the long-retired Admiral and former Chief of the Bureau of Ordnance Joseph Strauss. The board requested an entirely new design study, again focusing on increasing the size of the 35000 LT South Dakota class. The first plans made for this indicated that 30 kn was possible on a standard displacement of about 37600 LT. 33 kn could be bought with 220000 shp and a standard displacement of around 39230 LT, which was well below the London Treaty's "escalator clause" maximum limit of 45000 LT.

These designs were able to convince the General Board that a reasonably well-designed and balanced 33-knot "fast" battleship was possible within the terms of the "escalator clause". However, further studies revealed major problems with the estimates. The speed of the ships meant that more freeboard would be needed both fore and amidships, the latter requiring an additional foot of armored freeboard. Along with this came the associated weight in supporting these new strains: the structure of the ship had to be reinforced and the power plant enlarged to avoid a drop in speed. In all, about 2400 LT had to be added, and the large margin the navy designers had previously thought they had – roughly 5000 LT – was suddenly vanishing. The draft of the ships was also allowed to increase, which enabled the beam to narrow and thus reduced the required power (since a lower beam-to-draft ratio reduces wave-making resistance). This also allowed the ships to be shortened, which reduced weight.

With the additional displacement, the General Board was incredulous that a tonnage increase of 10000 LT would allow only the addition of 6 kn over the South Dakotas. Rather than retaining the 16-inch/45 caliber Mark 6 guns used in the South Dakotas, they ordered that the preliminary design would have to include the more powerful but significantly heavier 16-inch/50 caliber Mark 2 guns left over from the canceled Lexington-class battlecruisers and South Dakota-class battleship (1920) battleships of the early 1920s.

The 16"/50 turret weighed some 400 LT more than the 16"/45 turret already in use and also had a larger barbette diameter of 39 ft compared to the latter's barbette diameter of 37 ft, so the total weight gain was about 2000 LT. This put the ship at a total of 46551 LT – well over the 45000 LT limit. An apparent savior appeared in a Bureau of Ordnance preliminary design for a turret that could carry the 50-caliber guns and also fit in the smaller barbette of the 45-caliber gun turret. Other weight savings were achieved by thinning some armor elements and substituting construction steel with armor-grade Special Treatment Steel (STS) in certain areas. The net savings reduced the preliminary design displacement to 44560 LT standard, though the margin remained tight. This breakthrough was shown to the General Board as part of a series of designs on 2 June 1938.

However, the Bureau of Ordnance continued working on the turret with the larger barbette, while the Bureau of Construction and Repair used the smaller barbettes in the contract design of the new battleships. As the bureaus were independent of one another, they did not realize that the two plans could not go together until November 1938, when the contract design was in the final stages of refinement. By this time, the ships could not use the larger barbette, as it would require extensive alterations to the design and would result in substantial weight penalties. Reverting to the 45-caliber gun was also deemed unacceptable. The General Board was astounded; one member asked the head of the Bureau of Ordnance if it had occurred to him that Construction and Repair would have wanted to know what turret his subordinates were working on "as a matter of common sense". A complete scrapping of plans was avoided only when designers within the Bureau of Ordnance were able to design a new 50-caliber gun, the Mark 7, that was both lighter and smaller in outside diameter; this allowed it to be placed in a turret that would fit in the smaller barbette. The redesigned 3-gun turret, equipped as it was with the Mark 7 naval gun, provided an overall weight saving of nearly 850 LT to the overall design of the Iowa class. The contract design displacement subsequently stood at 45155 LT standard and 56088 LT full load.

In May 1938, the United States Congress passed the Second Vinson Act, which "mandated a 20% increase in strength of the United States Navy". The act was sponsored by Carl Vinson, a Democratic Congressman from Georgia who was Chairman of the House Naval Affairs and Armed Services Committee. The Second Vinson Act updated the provisions of the Vinson-Trammell Act of 1934 and the Naval Act of 1936, which had "authorized the construction of the first American battleships in 17 years", based on the provisions of the London Naval Treaty of 1930; this act was quickly signed by President Franklin D. Roosevelt and provided the funding to build the Iowa class. Each ship cost approximately US$100 million.

As 1938 drew to a close, the contract design of the Iowas was nearly complete, but it would continuously evolve as the New York Navy Yard, the lead shipyard, conducted the final detail design. These revisions included changing the design of the foremast, replacing the original 1.1 in/75-caliber guns that were to be used for anti-aircraft (AA) work with 20 mm/70 caliber Oerlikon cannons and 40 mm/56 caliber Bofors guns, and moving the combat information center into the armored hull. Additionally, in November 1939, the New York Navy Yard greatly modified the internal subdivision of the machinery rooms, as tests had shown the underwater protection in these rooms to be inadequate. The longitudinal subdivision of these rooms was doubled, and the result of this was clearly beneficial: "The prospective effect of flooding was roughly halved and the number of uptakes and hence of openings in the third deck greatly reduced." Although the changes meant extra weight and increasing the beam by 1 ft to 108 ft, this was no longer a major issue; Britain and France had renounced the Second London Naval Treaty soon after the beginning of the Second World War. The design displacement was 45873 LT standard, approximately 2% overweight, when Iowa and New Jersey were laid down in June and September 1940. By the time the Iowas were completed and commissioned in 1943–44, the considerable increase in anti-aircraft armament – along with their associated splinter protection and crew accommodations – and additional electronics had increased standard displacement to some 47825 LT, while full load displacement became 57540 LT.

General characteristics

The Iowa-class battleships are 860 ft long at the waterline and 887 ft long overall with a beam of 108 ft. During World War II, the draft was 37 ft at full load displacement of 57540 LT and 34 ft at design combat displacement of 54889 LT. Like the two previous classes of American fast battleships, the Iowas have a double bottom hull that becomes a triple bottom under the armored citadel and armored skegs around the inboard shafts. The dimensions of the Iowas were strongly influenced by speed. When the Second Vinson Act was passed by the United States Congress in 1938, the U.S. Navy moved quickly to develop a 45,000-ton-standard battleship that would pass through the 110 ft wide Panama Canal. Drawing on a 1935 empirical formula for predicting a ship's maximum speed based on scale-model studies in flumes of various hull forms and propellers and a newly developed empirical theorem that related waterline length to maximum beam, the Navy drafted plans for a battleship class with a maximum beam of 108 ft which, when multiplied by 7.96, produced a waterline length of 860 ft. The Navy also called for the class to have a lengthened forecastle and amidship, which would increase speed, and a bulbous bow.

The Iowas exhibit good stability, making them steady gun platforms. At design combat displacement, the ships' (GM) metacentric height was 9.26 ft. They also have excellent maneuverability in the open water for their size, while seakeeping is described as good, but not outstanding. In particular, the long fine bow and sudden widening of the hull just in front of the foremost turret contributed to the ships being rather wet for their size. This hull form also resulted in very intense spray formations, which led to some difficulty refueling escorting destroyers.

Main battery
The primary guns used on these battleships are the nine 16 in/50-caliber Mark 7 naval guns, a compromise design developed to fit inside the barbettes. These guns fire high explosive- and armor-piercing shells and can fire a 16-inch shell approximately 23.4 nmi. The guns are housed in three 3-gun turrets: two forward of the battleship's superstructure and one aft, in a configuration known as "2-A-1". The guns are 66 ft long (50 times their 16-inch bore, or 50 calibers from breechface to muzzle). About 43 ft protrudes from the gun house. Each gun weighs about 239000 lb without the breech, or 267900 lb with the breech. They fired 2700 lb armor-piercing projectiles at a muzzle velocity of 2500 ft/s, or 1900 lb high-capacity projectiles at 2690 ft/s, up to 24 mi. At maximum range, the projectile spends almost $1 1⁄2$ minutes in flight. The maximum firing rate for each gun is two rounds per minute.

Each gun rests within an armored turret, but only the top of the turret protrudes above the main deck. The turret extends either four decks (Turrets 1 and 3) or five decks (Turret 2) down. The lower spaces contain rooms for handling the projectiles and storing the powder bags used to fire them. Each turret required a crew of between 85 and 110 men to operate. The original cost for each turret was US$1.4 million, but this figure does not take into account the cost of the guns themselves. The turrets are "three-gun", not "triple", because each barrel is individually sleeved and can be elevated and fired independently. The ship could fire any combination of its guns, including a broadside of all nine. The fire control was performed by the Mark 38 Gun Fire Control System (GFCS); the firing solutions were computed with the Mark 8 rangekeeper, an analog computer that automatically receives information from the director and Mark 8/13 fire control radar, stable vertical, ship pitometer log and gyrocompass, and anemometer. The GFCS uses remote power control (RPC) for automatic gun laying.

The large-caliber guns were designed to fire two different conventional 16-inch shells: the 2700 lb Mk 8 "Super-heavy" APC (Armor Piercing, Capped) shell for anti-ship and anti-structure work, and the 1900 lb Mk 13 high-explosive round designed for use against unarmored targets and shore bombardment. When firing the same conventional shell, the 16-inch/45 caliber Mark 6 used by the fast battleships of the North Carolina and South Dakota classes had a slight advantage over the 16-inch/50 caliber Mark 7 gun when hitting deck armor – a shell from a 45 cal gun would be slower, meaning that it would have a steeper trajectory as it descended. At 35000 yd, a shell from a 45 cal would strike a ship at an angle of 45.2 degrees, as opposed to 36 degrees with the 50 cal. The Mark 7 had a greater maximum range over the Mark 6: 23.64 mi vs 22.829 mi.

In the 1950s, the W23, an adaptation of the W19 nuclear artillery shell was developed specifically for the 16-inch guns. The shell weighed 1900 lb had an estimated yield of 15 to 20 ktonTNT, and its introduction made the Iowa-class battleships' 16-inch guns the world's largest nuclear artillery and made these four battleships the only US Navy ships ever to have nuclear shells for naval guns. Although developed for exclusive use by the battleship's guns it is not known if any of the Iowas actually carried these shells while in active service due to the United States Navy's policy of refusing to confirm or deny the presence of nuclear weaponry aboard its ships. In 1991, the United States unilaterally withdrew all of its nuclear artillery shells from service, and the dismantling of the US nuclear artillery inventory is said to have been completed in 2004.

Secondary battery
The Iowas carried twenty 5 in/38 caliber Mark 12 guns in ten Mark 28 Mod 2 enclosed base ring mounts. Originally designed to be mounted upon destroyers built in the 1930s, these guns were so successful that they were added to many American ships during the Second World War, including every major ship type and many smaller warships constructed between 1934 and 1945. They were considered to be "highly reliable, robust and accurate" by the Navy's Bureau of Ordnance.

Each 5-inch/38 gun weighed almost 4000 lb without the breech; the entire mount weighed 156295 lb. It was 223.8 in long overall, had a bore length of 190 in, and a rifling length of 157.2 in. The gun could fire shells at about 2500 –; about 4,600 could be fired before the barrel needed to be replaced. Minimum and maximum elevations were −15 and 85 degrees, respectively. The guns' elevation could be raised or lowered at about 15 degrees per second. The mounts closest to the bow and stern could aim from −150 to 150 degrees; the others were restricted to −80 to 80 degrees. They could be turned at about 25 degrees per second. The mounts were directed by four Mark 37 fire control systems primarily through remote power control (RPC).

The 5-inch/38 gun functioned as a dual-purpose gun (DP); that is, it was able to fire at both surface and air targets with a reasonable degree of success. However, this did not mean that it possessed inferior anti-air abilities. As proven during 1941 gunnery tests conducted aboard USS North Carolina (BB-55) the gun could consistently shoot down aircraft flying at 12000 –, twice the effective range of the earlier single-purpose 5-inch/25 caliber AA gun. As Japanese airplanes became faster, the gun lost some of its effectiveness in the anti-aircraft role; however, toward the end of the war, its usefulness as an anti-aircraft weapon increased again because of an upgrade to the Mark 37 Fire Control System, Mark 1A computer, and proximity-fused shells.

The 5-inch/38 gun would remain on the battleships for the ships' entire service life; however, the total number of guns and gun mounts was reduced from twenty guns in ten mounts to twelve guns in six mounts during the 1980s' modernization of the four Iowas. The removal of four of the gun mounts was required for the battleships to be outfitted with the armored box launchers needed to carry and fire Tomahawk missiles. At the time of the 1991 Persian Gulf War, these guns had been largely relegated to littoral defense for the battleships. Since each battleship carried a small detachment of Marines aboard, the Marines would man one of the 5-inch gun mounts.

Anti-air battery

At the time of their commissioning, all four of the Iowa-class battleships were equipped with 20 quad 40 mm mounts and 49 single 20 mm mounts. These guns were respectively augmented with the Mk 14 range sight and Mk 51 fire control system to improve accuracy.

The Oerlikon 20 mm gun, one of the most heavily produced anti-aircraft guns of the Second World War, entered service in 1941 and replaced the 0.50 in M2 Browning MG on a one-for-one basis. Between December 1941 and September 1944, 32% of all Japanese aircraft downed were credited to this weapon, with the high point being 48.3% for the second half of 1942; however, the 20 mm guns were found to be ineffective against the Japanese Kamikaze attacks used during the latter half of World War II and were subsequently phased out in favor of the heavier Bofors 40 mm AA gun.

When the Iowa-class battleships were commissioned in 1943 and 1944, they carried twenty quad 40 mm AA gun mounts, which they used for defense against enemy aircraft. These heavy AA guns were also employed in the protection of Allied aircraft carriers operating in the Pacific Theater of World War II, and accounted for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945. Although successful in this role against WWII aircraft, the 40 mm guns were stripped from the battleships in the jet age – initially from New Jersey when reactivated in 1968 and later from Iowa, Missouri, and Wisconsin when they were reactivated for service in the 1980s.

Propulsion
The powerplant of the Iowas consists of eight Babcock & Wilcox boilers and four sets of double reduction cross-compound geared turbines, with each turbine set driving a single shaft. Specifically, the geared turbines on Iowa and Missouri were provided by General Electric, while the equivalent machinery on New Jersey and Wisconsin was provided by Westinghouse. The plant produced 212000 shp and propelled the ship up to a maximum speed of 32.5 kn at full load displacement and 33 kn at normal displacement. The ships carried 8841 LT of fuel oil which gave a range of 15900 nmi at 17 kn. Two semi-balanced rudders gave the ships a tactical turning diameter of 814 yard at 30 kn and 760 yard at 20 kn.

The machinery spaces were longitudinally divided into eight compartments with alternating fire and engine rooms to ensure adequate isolation of machinery components. Four fire rooms each contained two M-Type boilers operating at 600 psi with a maximum superheater outlet temperature of 850 °F. The double-expansion engines consist of a high-pressure (HP) turbine and a low-pressure (LP) turbine. The steam is first passed through the HP turbine which turns at up to 2,100 rpm. The steam, largely depleted at this point, is then passed through a large conduit to the LP turbine. By the time it reaches the LP turbine, it has no more than 50 psi of pressure left. The LP turbine increases efficiency and power by extracting the last little bit of energy from the steam. After leaving the LP turbine, the exhaust steam passes into a condenser and is then returned as feed water to the boilers. Water lost in the process is replaced by three evaporators, which can make a total of 60,000 US gallons per day (3 liters per second) of fresh water. After the boilers have had their fill, the remaining fresh water is fed to the ship's potable water systems for drinking, showers, hand washing, cooking, etc. All of the urinals and all but one of the toilets on the Iowa class flush with salt water in order to conserve fresh water. The turbines, especially the HP turbine, can turn at 2,000 rpm; their shafts drive through reduction gearing that turns the propeller shafts at speeds up to 225 rpm, depending upon the desired speed of the ship. The Iowas were outfitted with four screws: the outboard pair consisting of four-bladed propellers 18.25 ft in diameter and the inboard pair consisting of five-bladed propellers 17 ft in diameter. The propeller designs were adopted after earlier testing had determined that propeller cavitation caused a drop in efficiency at speeds over 30 kn. The two inner shafts were housed in skegs to smooth the flow of water to the propellers and improve the structural strength of the stern.

Each of the four engine rooms has a pair of 1,250 kW Ship's Service Turbine Generators (SSTGs), providing the ship with a total non-emergency electrical power of 10,000 kW at 450 volts alternating current. Additionally, the vessels have a pair of 250 kW emergency diesel generators. To allow battle-damaged electrical circuits to be repaired or bypassed, the lower decks of the ship have a Casualty Power System whose large 3-wire cables and wall outlets called "biscuits" can be used to reroute power.

Electronics (1943–69)
The earliest search radars installed were the SK air-search radar and SG surface-search radar during World War II. They were located on the mainmast and forward fire-control tower of the battleships, respectively. As the war drew to a close, the United States introduced the SK-2 air-search radar and SG surface-search radar; the Iowa class was updated to make use of these systems between 1945 and 1952. At the same time, the ships' radar systems were augmented with the installation of the SP height finder on the main mast. In 1952, AN/SPS-10 surface-search radar and AN/SPS-6 air-search radar replaced the SK and SG radar systems, respectively. Two years later the SP height finder was replaced by the AN/SPS-8 height finder, which was installed on the main mast of the battleships.

In addition to these search and navigational radars, the Iowa class were also outfitted with a variety of fire control radars for their gun systems. Beginning with their commissioning, the battleships made use of a pair of Mk 38 gun fire control systems with Mark 8 fire control radar to direct the 16-inch guns and a quartet of Mk 37 gun fire control systems with Mark 12 fire control radar and Mark 22 height finding radar to direct the 5-inch gun batteries. These systems were upgraded over time with the Mark 13 replacing the Mark 8 and the Mark 25 replacing the Mark 12/22, but they remained the cornerstones of the combat radar systems on the Iowa class during their careers. The range estimation of these gunfire control systems provided a significant accuracy advantage over earlier ships with optical rangefinders; this was demonstrated off Truk Atoll on 16 February 1944, when the New Jersey engaged the JAPANESE DESTROYER Nowaki at a range of 35700 yd and straddled her, setting the record for the longest-ranged straddle in history.

In World War II, the electronic countermeasures (ECM) included the SPT-1 and SPT-4 equipment; passive electronic support measures (ESM) were a pair of DBM radar direction finders and three intercept receiving antennas, while the active components were the TDY-1 jammers located on the sides of the fire control tower. The ships were also equipped with the identification, friend or foe (IFF) Mark III system, which was replaced by the IFF Mark X when the ships were overhauled in 1955. When the New Jersey was reactivated in 1968 for the Vietnam War, she was outfitted with the ULQ-6 ECM system.

Armor

Like all battleships, the Iowas carried heavy armor protection against shellfire and bombs with significant underwater protection against torpedoes. The Iowas' "all-or-nothing" armor scheme was largely modeled on that of the preceding South Dakota class, and designed to give a zone of immunity against fire from 16-inch/45-caliber guns between 18000 and 30000 yd away. The protection system consists of Class A face-hardened Krupp cemented (K.C.) armor and Class B homogeneous Krupp-type armor; furthermore, special treatment steel (STS), a high-tensile structural steel with armor properties comparable to Class B, was extensively used in the hull plating to increase protection.

The citadel consisting of the magazines and engine rooms was protected by an STS outer hull plating 1.5 in thick and a Class A armor belt 12.1 in thick mounted on 0.875 in STS backing plate; the armor belt is sloped at 19 degrees, equivalent to 17.3 in of vertical class B armor at 19,000 yards. The armor belt extends to the triple bottom, where the Class B lower portion tapers to 1.62 in. The ends of the armored citadel are closed by 11.3 in vertical Class A transverse bulkheads for Iowa and New Jersey. The transverse bulkhead armor on Missouri and Wisconsin was increased to 14.5 in; this extra armor provided protection from raking fire directly ahead, which was considered more likely given the high speed of the Iowas. The deck armor consists of a 1.5 in STS weather deck, a combined 6 in Class B and STS main armor deck, and a 0.63 in STS splinter deck. Over the magazines, the splinter deck is replaced by a 1 in STS third deck that separates the magazine from the main armored deck. The powder magazine rooms are separated from the turret platforms by a pair of 1.5-inch STS annular bulkheads under the barbettes for flashback protection. The installation of armor on the Iowas also differed from those of earlier battleships in that the armor was installed while the ships were still "on the way" rather than after the ships had been launched.

The Iowas had heavily protected main battery turrets, with 19.5 in Class B and STS face, 9.5 in Class A sides, 12 in Class A rear, and 7.25 in Class B roof. The turret barbettes' armor is Class A with 17.3 in abeam and 11.6 in facing the centerline, extending down to the main armor deck. The conning tower armor is Class B with 17.3 in on all sides and 7.25 in on the roof. The secondary battery turrets and handling spaces were protected by 2.5 in of STS. The propulsion shafts and steering gear compartment behind the citadel had considerable protection, with 13.5 in Class A side strake and 5.6-6.2 in roof.

The armor's immunity zone shrank considerably against guns equivalent to their own 16-inch/50-caliber guns armed with the Mk 8 armor-piercing shell due to the weapon's increased muzzle velocity and improved shell penetration; increasing the armor would have increased weight and reduced speed, a compromise that the General Board was not willing to make.

The Iowas' torpedo defense was based on the South Dakotas' design, with modifications to address shortcomings discovered during caisson tests. The system is an internal "bulge" that consists of four longitudinal torpedo bulkheads behind the outer hull plating with a system depth of 17.9 ft to absorb the energy of a torpedo warhead. The extension of the armor belt to the triple bottom, where it tapers to a thickness of 1.62 in, serves as one of the torpedo bulkheads and was hoped to add to protection; the belt's lower edge was welded to the triple bottom structure and the joint was reinforced with buttstraps due to the slight knuckle causing a structural discontinuity. The torpedo bulkheads were designed to elastically deform to absorb energy and the two outer compartments were liquid loaded in order to disrupt the gas bubble and slow fragments. The outer hull was intended to detonate a torpedo, with the outer two liquid compartments absorbing the shock and slowing any splinters or debris while the lower armored belt and the empty compartment behind it absorb any remaining energy. However, the Navy discovered in caisson tests in 1939 that the initial design for this torpedo defense system was actually less effective than the previous design used on the North Carolinas due to the rigidity of the lower armor belt causing the explosion to significantly displace the final holding bulkhead inwards despite remaining watertight. To mitigate the effects, the third deck and triple bottom structure behind the lower armor belt were reinforced and the placement of brackets was changed. Iowas' system was also improved over the South Dakotas' through closer spacing of the transverse bulkheads, greater thickness of the lower belt at the triple bottom joint, and increased total volume of the "bulge". The system was further modified for the last two ships of the class, Illinois and Kentucky, by eliminating knuckles along certain bulkheads; this was estimated to improve the strength of the system by as much as 20%.

Based on costly lessons in the Pacific theater, concerns were raised about the ability of the armor on these battleships to withstand aerial bombing, particularly high-altitude bombing using armor-piercing bombs. Developments such as the Norden bombsight further fueled these concerns. While the design of the Iowas was too far along to adequately address this issue, experience in the Pacific theater eventually demonstrated that high-altitude unguided bombing was ineffective against maneuvering warships.

Aircraft (1943–69)
When they were commissioned during World War II, the Iowa-class battleships came equipped with two aircraft catapults designed to launch floatplanes. Initially, the Iowas carried the Vought OS2U Kingfisher and Curtiss SC Seahawk, both of which were employed to spot for the battleship's main gun batteries – and, in a secondary capacity, perform search-and-rescue missions.

By the time of the Korean War, helicopters had replaced floatplanes and the Sikorsky HO3S-1 helicopter was employed. New Jersey made use of the Gyrodyne QH-50 DASH drone for her Vietnam War deployment in 1968–69.

Conversion proposals
The Iowa class were the only battleships with the speed required for post-war operations based around fast aircraft carrier task forces. There were several proposals in the early Cold War to convert the class to take into account changes in technology and doctrine. These included plans to equip the class with nuclear missiles, add aircraft capability, and – in the case of Illinois and Kentucky – a proposal to rebuild both as aircraft carriers instead of battleships.

Initially, the Iowa class was to consist of only four battleships with hull numbers BB-61 to BB-64: Iowa, New Jersey, Missouri, and Wisconsin. However, changing priorities during World War II resulted in the battleship hull numbers BB-65 USS Montana (BB-67) and BB-66 USS Ohio (BB-68) being reordered as Illinois and Kentucky, respectively; Montana and Ohio were reassigned to hull numbers BB-67 and BB-68. At the time these two battleships were to be built a proposal was put forth to have them constructed as aircraft carriers rather than fast battleships. The plan called for the ships to be rebuilt to include a flight deck and an armament suite similar to that placed aboard the Essex-class aircraft carriers that were at the time under construction in the United States. Ultimately, nothing came of the design proposal to rebuild these two ships as aircraft carriers and they were cleared for construction as fast battleships to conform to the Iowa-class design, though they differed from the earlier four that were built. Eventually, the Cleveland-class cruiser light cruisers were selected for the aircraft-carrier conversion. Nine of these light cruisers would be rebuilt as Independence-class aircraft carrier light aircraft carriers.

After the surrender of the Empire of Japan, construction on Illinois and Kentucky stopped. Illinois was eventually scrapped, but Kentucky's construction had advanced enough that several plans were proposed to complete Kentucky as a guided missile battleship (BBG) by removing the aft turret and installing a missile system. A similar conversion had already been performed on the battleship USS Mississippi (BB-41) (BB-41/AG-128) to test the RIM-2 Terrier missile after World War II. One such proposal came from Rear Admiral W.K. Mendenhall, Chairman of the Ship Characteristics Board (SCB); Mendenhall proposed a plan that called for $15–30 million to be spent to allow Kentucky to be completed as a guided-missile battleship (BBG) carrying eight SSM-N-8 Regulus II guided missiles with a range of 1000 nmi. He also suggested Terrier or RIM-8 Talos launchers to supplement the AA guns and proposed nuclear (instead of conventional) shells for the 16-inch guns. This never materialized, and Kentucky was ultimately sold for scrap in 1958, although her bow was used to repair her sister Wisconsin after a collision on 6 May 1956, earning her the nickname WisKy.

In 1954, the Long Range Objectives Group of the United States Navy suggested converting the Iowa-class ships to BBGs. In 1958, the Bureau of Ships offered a proposal based on this idea. This replaced the 5- and 16-inch gun batteries with "two Talos twin missile systems, two RIM-24 Tartar twin missile systems, an RUR-5 ASROC antisubmarine missile launcher, and a Regulus II installation with four missiles", as well as flagship facilities, sonar, helicopters, and fire-control systems for the Talos and Tartar missiles. In addition to these upgrades, 8600 LT of additional fuel oil was also suggested to serve in part as ballast for the battleships and for use in refueling destroyers and cruisers. Due to the estimated cost of the overhaul ($178–193 million) this proposal was rejected as too expensive; instead, the SCB suggested a design with one Talos, one Tartar, one ASROC, and two Regulus launchers and changes to the superstructure, at a cost of up to $85 million. This design was later revised to accommodate the Polaris Fleet Ballistic Missile, which in turn resulted in a study of two schemes by the SCB. In the end, none of these proposed conversions for the battleships were ever authorized. Interest in converting the Iowas into guided-missile battleships began to deteriorate in 1960 because the hulls were considered too old and the conversion costs too high. Nonetheless, additional conversion proposals – including one to install the AN/SPY-1 Aegis Combat System radar on the battleships – were suggested in 1962, 1974, and 1977, but as before, these proposals failed to gain the needed authorization. This was due, in part, to the possibility that sensitive electronics within 200 ft of any 16-inch gun muzzle may be damaged from overpressure.

1980s Reactivation/Modernization

In 1980, Ronald Reagan was elected president on a promise to build up the US military as a response to the increasing military power of the Soviet Union. The Soviet Navy was commissioning the Kirov class of missile cruisers, the largest type of surface combatant since World War II. As part of Reagan's 600-ship Navy policy and as a counter to the Kirov class, the US Navy began reactivating the four Iowa-class units and modernizing them for service.

The Navy considered several proposals that would have removed the aft 16-inch turret. Martin Marietta proposed to replace the turret with servicing facilities for 12 AV-8B Harrier STOVL jump jets. Charles Myers, a former Navy test pilot turned Pentagon consultant, proposed replacing the turret with vertical launch systems for missiles and a flight deck for Marine helicopters. In July 1981, the US Naval Institute's Proceedings published a proposal by naval architect Gene Anderson for a canted flight deck with steam catapult and arrestor wires for F/A-18 Hornet fighters. Plans for these conversions were dropped in 1984.

Each battleship was overhauled to burn navy distillate fuel and modernized to carry electronic warfare suites, close-in weapon systems (CIWS) for self-defense, and missiles. The obsolete electronics and anti-aircraft armament were removed to make room for more modern systems. The Navy spent about $1.7 billion, from 1981 through 1988, to modernize and reactivate the four Iowa-class battleships, roughly the same as building four Oliver Hazard Perry-class frigates.

After modernization, the full load displacement was relatively unchanged at 57500 LT.

The modernized battleships operated as centerpieces of their own battle group (termed as a Battleship Battle Group or Surface Action Group), consisting of one Ticonderoga-class cruiser, one Kidd-class destroyer or Arleigh Burke-class destroyer, one Spruance-class destroyer, three Oliver Hazard Perry-class frigates and one support ship, such as a fleet oiler.

Armament
During their modernization in the 1980s, each Iowa was equipped with four of the US Navy's Phalanx CIWS mounts, two of which sat just behind the bridge and two which were next to the ship's aft funnel. Iowa, New Jersey, and Missouri were equipped with the Block 0 version of the Phalanx, while Wisconsin received the first operational Block 1 version in 1988. The Phalanx system is intended to serve as a last line of defense against enemy missiles and aircraft, and when activated can engage a target with a 20 mm M61 Vulcan 6-barreled Gatling cannon at a distance of approximately 4000 yd.

As part of their modernization in the 1980s, each of the Iowas received a complement of eight quad-cell Armored Box Launchers and four "shock hardened" Mk 141 quad-cell launchers. The former was used by the battleships to carry and fire the BGM-109 Tomahawk Land Attack Missiles (TLAMs) for use against enemy targets on land, while the latter system enabled the ships to carry a complement of RGM-84 Harpoon anti-ship missiles for use against enemy ships. With an estimated range of 675 to 1500 nmi for the Tomahawks and 64.5 to 85.5 nmi for the Harpoons, these two missile systems displaced the 16-inch guns and their maximum range of 42345 yd to become the longest-ranged weapons on the battleships during the 1980s; the ships' complement of 32 Tomahawk missiles was the largest until the Mk 41 VLS-equipped Ticonderoga-class cruiser cruisers entered service. It has been alleged by members of the environmental group Greenpeace that the battleships carried the TLAM-A (also cited, incorrectly, as the TLAM-N) – a Tomahawk missile with a variable yield W80 nuclear warhead – during their 1980s service with the United States Navy, but owing to the United States Navy's policy of refusing to confirm or deny the presence of nuclear weaponry aboard its ships, these claims can not be conclusively proved. Between 2010 and 2013, the US withdrew the BGM-109A, leaving only conventional munitions packages for its Tomahawk missile inventory, though the Iowas had been withdrawn from service at that point.

Owing to the original 1938 design of the battleships, the Tomahawk missiles could not be fitted to the Iowa class unless the battleships were rebuilt in such a way as to accommodate the missile mounts that would be needed to store and launch the Tomahawks. This realization prompted the removal of the anti-aircraft guns previously installed on the Iowas and the removal of four of each of the battleships' ten 5-inch/38 DP mounts. The mid and aft end of the battleships were then rebuilt to accommodate the missile launchers. At one point, the NATO Sea Sparrow was to be installed on the reactivated battleships; however, it was determined that the system could not withstand the overpressure effects of firing the main battery. To supplement the anti-aircraft capabilities of the Iowas, five FIM-92 Stinger surface-to-air missile firing positions were installed. These secured the shoulder-launched weapons and their rounds for ready use by the crew.

Electronics
During their modernization under the 600-ship Navy program, the Iowa-class battleships' radar systems were again upgraded. The foremast was of a new tripod design that was considerably reinforced to allow the AN/SPS-6 air-search radar system to be replaced with the AN/SPS-49 radar set (which also augmented the existing navigation capabilities on the battleships), and the AN/SPS-8 surface-search radar set was replaced by the AN/SPS-67 search radar. The new mast also incorporates a Tactical Air Navigation System (TACAN) antenna. The aft mast was changed to be placed in front of the aft funnel and mounts a circular SATCOM antenna while another one was mounted on the fire control mast.

By the Korean War, jet engines had replaced propellers on aircraft, which severely limited the ability of the 20 mm and 40 mm AA batteries and their gun systems to track and shoot down enemy planes. Consequently, the AA guns and their associated fire-control systems were removed when reactivated. New Jersey received this treatment in 1967, and the others followed in their 1980s modernizations. In the 1980s, each ship also received a quartet of Phalanx CIWS mounts which made use of a radar system to locate incoming enemy projectiles and destroy them with a 20 mm Gatling gun before they could strike the ship. With the added missile capacity of the battleships in the 1980s came additional fire-support systems to launch and guide the ordnance. To fire the Harpoon anti-ship missiles, the battleships were equipped with the SWG-1 fire-control system, and to fire the Tomahawk missiles the battleships used either the SWG-2 or SWG-3 fire-control system. In addition to these offensive-weapon systems, the battleships were outfitted with the AN/SLQ-25 Nixie to be used as a lure against enemy torpedoes; an SLQ-32 electronic warfare system that can detect, jam, and deceive an opponent's radar; and a Mark 36 SRBOC system to fire chaff rockets intended to confuse enemy missiles.

Aside from the electronics added for weaponry control, all four battleships were outfitted with a communications suite used by both cruisers and guided missile cruisers in service at the time. This communication suite included the OE-82 antenna for satellite communications but did not include the Naval Tactical Data System.

Aircraft (1982–1992)

During the 1980s these battleships made use of the RQ-2 Pioneer, an unmanned aerial vehicle employed in spotting for the guns. Launched from the fantail using a rocket-assist booster that was discarded shortly after takeoff, the Pioneer carried a video camera in a pod under the belly of the aircraft which transmitted live video to the ship so operators could observe enemy actions or fall of shot during naval gunnery. To land the UAV a large net was deployed at the back of the ship; the aircraft was flown into it. Missouri and Wisconsin both used the Pioneer UAVs successfully during Operation Desert Storm, and in one particularly memorable incident, a Pioneer UAV operated by Wisconsin received the surrender of Iraqi troops during combat operations. This particular Pioneer was later donated to the Smithsonian Institution and is now on public display. During Operation Desert Storm these Pioneers were operated by detachments of VC-6. In addition to the Pioneer UAVs, the recommissioned Iowas could support six types of helicopters: the Sikorsky HO3S-1, UH-1 Iroquois, SH-2 Seasprites, CH-46 Sea Knight, CH-53 Sea Stallion, and LAMPS III SH-60B Seahawk.

Gunfire support role
Following the 1991 Gulf War and the subsequent dissolution of the Soviet Union, the United States Navy began to decommission and mothball many of the ships it had brought out of its reserve fleet in the drive to attain a 600-ship Navy. At the height of Navy Secretary John F. Lehman's 600-ship Navy plan, nearly 600 ships of all types were active within the Navy. This included fifteen aircraft carriers, four battleships, and over 100 submarines, along with various other types of ships the overall plan specified. When the Soviet Union collapsed in 1991 the Navy sought to return to its traditional, 313-ship composition. While reducing the fleet created under the 600-ship Navy program, the decision was made to deactivate the four recommissioned Iowa-class battleships and return them to the reserve fleet.

In 1995, the decommissioned battleships were removed from the Naval Vessel Register after it was determined by ranking US Navy officials that there was no place for a battleship in the modern navy. In response to the striking of the battleships from the Naval Vessel Register a movement began to reinstate the battleships, on the grounds that these vessels had superior firepower over the 5-inch guns found on the Spruance, Kidd and Arleigh Burke-class destroyers and Ticonderoga-class cruisers. Citing concern over the lack of available gunfire to support amphibious operations, Congress required the Navy to reinstate two battleships to the Naval Vessel Register and maintain them with the mothball fleet, until the Navy could certify it had gunfire support within the current fleet that would meet or exceed the battleship's capability.

The debate over battleships in the modern navy continued until 2006, when the two reinstated battleships were stricken after naval officials submitted a two-part plan that called for the near-term goal of increasing the range of the guns in use on the Arleigh Burke-class destroyers with new Extended Range Guided Munition (ERGM) ammunition intended to allow a 5-inch projectile fired from these guns to travel an estimated 40 nmi inland. The long-term goal called for the replacement of the two battleships with 32 vessels of the Zumwalt-class destroyer of guided-missile destroyers. Cost overruns caused the class to be reduced to three ships. These ships are outfitted with an Advanced Gun System (AGS) that was to fire specially developed 6-inch Long Range Land Attack Projectiles for shore bombardment. LRLAP procurement was canceled in 2017 and the AGS is unusable. The long-term goal for the Zumwalt class is to have the ships mount railguns or free-electron lasers.

Cultural significance

The Iowa class became culturally symbolic in the United States in many different ways, to the point where certain elements of the American public – such as the United States Naval Fire Support Association – were unwilling to part with the battleships, despite their apparent obsolescence in the face of modern naval combat doctrine that places great emphasis on air supremacy and missile firepower. Although all were officially stricken from the Naval Vessel Register they were spared scrapping and were donated for use as museum ships.

Their service records added to their fame, ranging from their work as carrier escorts in World War II to their shore bombardment duties in North Korea, North Vietnam, and the Middle East, as well as their service in the Cold War against the expanded Soviet Navy. Their reputation combined with the stories told concerning the firepower of these battleships' 16-inch guns were such that when they were brought out of retirement in the 1980s in response to increased Soviet Naval activity – and in particular, in response to the commissioning of the Kirov-class battlecruisers – the United States Navy was inundated with requests from former sailors pleading for a recall to active duty so they could serve aboard one of the battleships.

In part because of the service length and record of the class, members have made numerous appearances in television shows, video games, movies, and other media, including appearances of the Kentucky and Illinois in the anime series Neon Genesis Evangelion, the History Channel documentary series Battle 360: USS Enterprise, the Discovery Channel documentary The Top 10 Fighting Ships (where the Iowa class was rated Number 1), the book turned movie A Glimpse of Hell, the 1989 music video for the song by Cher "If I Could Turn Back Time", the 1992 film Under Siege, the 2012 film Battleship, among other appearances. Japanese rock band Vamps performed the finale of their 2009 US tour on board Missouri on 19 September 2009.

Ships in class

When brought into service during the final years of World War II, the Iowa-class battleships were assigned to operate in the Pacific Theatre of World War II. By this point in the war, aircraft carriers had displaced battleships as the primary striking arm of both the United States Navy and the Imperial Japanese Navy. As a result of this shift in tactics, US fast battleships of all classes were relegated to the secondary role of carrier escorts and assigned to the Fast Carrier Task Force to provide anti-aircraft screening for Allied aircraft carriers and perform shore bombardment. Three were recalled to service in the 1950s with the outbreak of the Korean War, and they provided naval artillery support for U.N. forces for the entire duration of the war before being returned to mothballs in 1955 after hostilities ceased. In 1968, to help alleviate US air losses over North Vietnam, New Jersey was summoned to Vietnam, but she was decommissioned a year after arriving. All four returned in the 1980s during the drive for a 600-ship Navy to counter the new Soviet Kirov-class battlecruisers, only to be retired after the collapse of the Soviet Union on the grounds that they were too expensive to maintain.

Iowa

Iowa was ordered 1 July 1939, laid down 27 June 1940, launched 27 August 1942, and commissioned 22 February 1943. She conducted a shakedown cruise in Chesapeake Bay before sailing to Naval Station Argentia, Newfoundland, to be ready in case the GERMAN BATTLESHIP Tirpitz entered the Atlantic. Transferred to the Pacific Fleet in 1944, Iowa made her combat debut in February and participated in the campaign for the Marshall Islands. The ship later escorted US aircraft carriers conducting air raids in the Marianas campaign, and then was present at the Battle of Leyte Gulf. During the Korean War, Iowa bombarded enemy targets at Songjin, Hŭngnam and Kojo, North Korea. Iowa returned to the US for operational and training exercises before being decommissioned on 24 February 1958. Reactivated in the early 1980s, Iowa operated in the Atlantic Fleet, cruising in North American and European waters for most of the decade and participating in joint military exercises with European ships. On 19 April 1989, 47 sailors were killed following an explosion in her No. 2 turret. In 1990, Iowa was decommissioned for the last time and placed in the mothball fleet. She was stricken from the Naval Vessel Register on 17 March 2006. Iowa was anchored as part of the National Defense Reserve Fleet in Suisun Bay, California until October 2011, when she was towed from her mooring to Richmond, California for renovation as a museum ship. She was towed from Richmond in the San Francisco Bay on 26 May 2012, to San Pedro at the Los Angeles Waterfront to serve as a museum ship run by Pacific Battleship Center and opened to the public on 7 July 2012.

New Jersey

New Jersey was ordered 4 July 1939, laid down 16 September 1940, launched 7 December 1942, and commissioned 23 May 1943. New Jersey completed fitting out and trained her initial crew in the Western Atlantic and Caribbean before transferring to the Pacific Theatre in advance of the planned assault on the Marshall Islands, where she screened the US fleet of aircraft carriers from enemy air raids. At the Battle of Leyte Gulf, the ship protected carriers with her anti-aircraft guns. New Jersey then bombarded Iwo Jima and Okinawa. During the Korean War, the ship pounded targets at Wonsan, Yangyang, and Kansong. Following the Armistice, New Jersey conducted training and operation cruises until she was decommissioned on 21 August 1957. Recalled to duty in 1968, New Jersey reported to the gunline off the Vietnamese coast and shelled North Vietnamese targets before departing the line in December 1968. She was decommissioned the following year. Reactivated in 1982 under the 600-ship Navy program, New Jersey was sent to Lebanon to protect US interests and US Marines, firing her main guns at Druze and Syrian positions in the Beqaa Valley east of Beirut. Decommissioned for the last time 8 February 1991, New Jersey was briefly retained on the Naval Vessel Register before being donated to the Home Port Alliance of Camden, New Jersey for use as a museum ship in October 2001.

Missouri

Missouri was the last of the four Iowas to be completed. She was ordered 12 June 1940, laid down 6 January 1941, launched 29 January 1944, and commissioned 11 June 1944. Missouri conducted her trials off New York with shakedown and battle practice in the Chesapeake Bay before transferring to the Pacific Fleet, where she screened US aircraft carriers involved in offensive operations against the Japanese before reporting to Okinawa to shell the island in advance of the planned landings. Following the bombardment of Okinawa, Missouri turned her attention to the Japanese homeland islands of Honshu and Hokkaido, performing shore bombardment and screening US carriers involved in combat operations. She became a symbol of the US Navy's victory in the Pacific when representatives of the Empire of Japan boarded the battleship to sign the documents of unconditional surrender to the Allied powers in September 1945. After World War II, Missouri conducted largely uneventful training and operational cruises until suffering a grounding accident. In 1950, she was dispatched to Korea in response to the outbreak of the Korean War. Missouri served two tours of duty in Korea providing shore bombardment. She was decommissioned in 1956. She spent many years at Puget Sound Naval Shipyard in Bremerton, Washington. Reactivated in 1984, as part of the 600-ship Navy plan, Missouri was sent on operational cruises until being assigned to Operation Earnest Will in 1988. In 1991, Missouri participated in Operation Desert Storm, firing 28 Tomahawk Missiles and 759 16-inch shells at Iraqi targets along the coast. Decommissioned for the last time in 1992, Missouri was donated to the USS Missouri Memorial Association of Pearl Harbor, Hawaii, for use as a museum ship in 1999.

Wisconsin

Wisconsin was ordered 12 June 1940, laid down 25 January 1942, launched 7 December 1943, and commissioned 16 April 1944. After trials and initial training in the Chesapeake Bay, she transferred to the Pacific Fleet in 1944 and was assigned to protect the US fleet of aircraft carriers involved in operations in the Philippines until summoned to Iwo Jima to bombard the island in advance of the Marine landings. Afterward, she proceeded to Okinawa, bombarding the island in advance of the Allied amphibious assault. In mid-1945 Wisconsin turned her attention to bombarding the Japanese home islands until the surrender of Japan in August. Reactivated in 1950, for the Korean War, Wisconsin served two tours of duty, assisting South Korean and UN forces by providing call fire support and shelling targets. In 1956, the bow of the uncompleted Kentucky was removed and grafted on Wisconsin, which had collided with the destroyer USS Eaton (DD-510). Decommissioned in 1958, Wisconsin was placed in the reserve fleet at the Philadelphia Naval Shipyard until reactivated in 1986 as part of the 600-ship Navy plan. In 1991, Wisconsin participated in Operation Desert Storm, firing 24 Tomahawk Missiles at Iraqi targets and expending 319 16-inch shells at Iraqi troop formations along the coast. Decommissioned for the last time 30 September 1991, Wisconsin was placed in the reserve fleet until stricken from the Naval Vessel Register on 17 March 2006, so she could be transferred for use as a museum ship. Wisconsin is currently berthed at the Nauticus maritime museum in Norfolk, Virginia.

Illinois and Kentucky

Hull numbers BB-65 and BB-66 were originally intended as the first and second ships of the Montana-class of battleships; however, the passage of an emergency war building program on 19 July 1940 resulted in both hulls being reordered as Iowa-class units to save time on construction. The war ended before either could be completed, and work was eventually stopped. Initially, proposals were made to convert the hulls into aircraft carriers similar to the Essex class, but the effort was dropped.

USS Illinois was ordered on 9 September 1940 and initially laid down on 6 December 1942. However, work was suspended pending a decision on whether to convert the hull to an aircraft carrier. Upon determination the result would cost more and be less capable than building from scratch, construction resumed, but it was canceled for good approximately one-quarter complete on 11 August 1945. She was sold for scrap and broken up on the slipway in September 1958.

USS Kentucky was ordered on 9 September 1940 and laid down on 7 March 1942. Work on the ship was suspended in June 1942, and the hull floated out to make room for the construction of LSTs. The interruption lasted for two and a half years while a parallel aircraft carrier debate played out as with Illinois, reaching the same conclusion. Work resumed in December 1944, with completion projected for mid-1946. Further suggestions were made to convert Kentucky into a specialist anti-aircraft ship, and work was again suspended. With the hull approximately three-quarters completed, she was floated on 20 January 1950, to clear a dry dock for repairs to Missouri, which had run aground. During this period, plans were proposed to convert Kentucky into a guided missile battleship, which saw her reclassified from BB-66 to BBG-1. When these failed construction of any sort, work never resumed and the ship was used as a parts hulk; in 1956, her bow was removed and shipped in one piece across Hampton Roads and grafted onto Wisconsin, which had collided with the destroyer Eaton. In 1958, the engines installed on Kentucky were salvaged and installed on the Sacramento-class fast combat support ships USS Sacramento (AOE-1) and USS Camden (AOE-2). Ultimately, what remained of the hulk was sold for scrap on 31 October 1958.

title: Iowa-class battleship


text:
Task Force 90 (United States)

Task Force 90 was a United States Navy task force.

In 1945 it was Aircraft, North Pacific Force, under Major General D. Johnson USA, part of North Pacific Force under Vice Admiral Frank Fletcher.

In the Korean War it controlled the amphibious forces in theatre. It reported directly to Commander Naval Forces Far East. Its most high-profile operation was the Incheon amphibious assault, Operation Chromite.

It was later active during Operation Passage to Freedom after the Geneva Accords of 1955.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Task Force 90 (United States)


text:
Sophie Tucker

Sophie Tucker (born Sofia Kalish; January 13, 1886 – February 9, 1966) was an American singer, comedian, actress, and radio personality. Known for her powerful delivery of comical and risqué songs, she was one of the most popular entertainers in the U.S. during the first half of the 20th century. She was known by the nickname "the Last of the Red-Hot Mamas".

Early life and education
Tucker was born Sofiya "Sonya" Kalish (Ukrainian: Соня Калиш; Russian, Софья «Соня» Калиш; סאָפיאַ קאַליש) in 1886 to a Jewish family in Tulchyn, Russian Empire, now Vinnytsia Oblast, Ukraine. (Sonya is a pet name for Sofiya in both Russian and Ukrainian as well as for Sofya, the Yiddish form of the name Sophia.) They arrived in Boston on September 26, 1887. The family adopted the surname Abuza before immigrating, her father fearing repercussions for having deserted from the Imperial Russian Army. The family lived in Boston's North End for eight years, then settled in Hartford, Connecticut, and opened a restaurant.

At a young age, she began singing at her parents' restaurant for tips. Between taking orders and serving customers, Tucker recalled that she "would stand up in the narrow space by the door and sing with all the drama I could put into it. At the end of the last chorus, between me and the onions, there wasn't a dry eye in the place."

In 1903, around the age of 17, Tucker eloped with Louis Tuck, a beer cart driver, from whom she later derived her professional surname. When she returned home, her parents arranged an Orthodox wedding for the couple. In 1905, she gave birth to a son, Albert. However, shortly after Albert was born, the couple separated, and Tucker left the baby with her family and moved to New York City.

Career
After she left her husband, Willie Howard gave Tucker a letter of recommendation to Harold Von Tilzer, a composer and theatrical producer in New York. When it failed to bring her work, Tucker found jobs in cafés and beer gardens, singing for food and tips from the customers. She sent most of what she made back home to Connecticut to support her son and family.

Stage
In 1907, Tucker made her first theater appearance, singing at an amateur night in a vaudeville establishment. The producers thought that the crowd would tease her for being "so big and ugly." Early in her career, Tucker appeared in blackface as a minstrel singer, but she disliked this work and would sabotage the act by revealing that she was white at the end of the show, first removing a glove to reveal her white hand, then by pulling off her wig and exposing her blonde hair. Tucker also began integrating "fat girl" humor, which became a common thread in her acts. Her songs included "I Don't Want to Get Thin" and "Nobody Loves a Fat Girl, But Oh How a Fat Girl Can Love." In 1909, Tucker performed with the Ziegfeld Follies. Though she was a hit, the other female stars refused to share the spotlight with her, and the company was forced to let her go. This caught the attention of William Morris, a theater owner and future founder of the William Morris Agency. Two years later, Tucker released "Some of These Days" on Edison Records, written by Shelton Brooks. The title of the song was used as the title of Tucker's 1945 biography.

In 1921, Tucker hired pianist and songwriter Ted Shapiro as her accompanist and musical director, a position he would keep throughout her career. Besides writing a number of songs for her, Shapiro became part of her stage act, playing piano on stage while she sang, and exchanging banter and wisecracks with her in between numbers. Tucker remained a popular singer through the 1920s and became friends with stars such as Mamie Smith and Ethel Waters, who introduced her to jazz. Tucker learned from these women and became one of the early performers to introduce jazz to white vaudeville audiences.

In 1925, Jack Yellen wrote "My Yiddishe Momme", a song which became strongly identified with her and was performed in cities which had a significant Jewish audience. Tucker said "Even though I loved the song and it was a sensational hit every time I sang it, I was always careful to use it only when I knew the majority of the house would understand Yiddish. However, you didn't have to be a Jew to be moved by 'My Yiddishe Momme'." The song was banned in Nazi Germany.

Popularity
By the 1920s, Tucker's success had spread to Europe, and she began a tour of England, performing for King George V and Queen Mary at the London Palladium in 1926. Tucker re-released her hit song "Some of These Days", backed by Ted Lewis and his band, which stayed at the number 1 position of the charts for five weeks beginning November 23, 1926. It sold over one million copies and was awarded a gold disc by the RIAA.

Tucker was strongly affected by the decline of vaudeville. Speaking about performing in the final show at E.F. Albee's Palace Theater in New York City, she remarked "Everyone knew the theater was to be closed down, and a landmark in show business would be gone. That feeling got into the acts. The whole place, even the performers, stank of decay. I seemed to smell it. It challenged me. I was determined to give the audience the idea: Why brood over yesterday? We have tomorrow. As I sang, I could feel the atmosphere change. The gloom began to lift, the spirit which formerly filled the Palace and which made it famous among vaudeville houses the world over came back. That's what an entertainer can do."

In 1929, she made her first movie appearance in Honky Tonk. During the 1930s, Tucker brought elements of nostalgia for the early years of the 20th century into her show. She was billed as "the Last of the Red Hot Mamas" as her hearty sexual appetite was a frequent subject of her songs, unusual for female performers of the day after the decline of vaudeville.

The cartoon The Woods Are Full of Cuckoos caricatures Tucker as Sophie Turkey.

American Federation of Actors
In 1938, Tucker was elected president of the American Federation of Actors, an early actors' trade union. Originally formed for vaudeville and circus performers, the union expanded to include nightclub performers and was chartered as a branch of the Associated Actors and Artistes.

In 1939, the union was disbanded by the American Federation of Labor (AFL) for financial mismanagement. However, Tucker was not implicated in the proceedings. The AFL later issued a charter for the succeeding American Guild of Variety Artists, which remains active.

Later days
In 1938–1939, Tucker had her own radio show, The Roi Tan Program with Sophie Tucker, broadcast on CBS for 15 minutes on Monday, Wednesday and Friday. She made numerous guest appearances on such programs as The Radio Hall of Fame and The Andrews Sisters' Show: Eight-to-the-Bar Ranch hosted by the Andrews Sisters. In the 1950s and early 1960s Tucker, "the First Lady of Show Business", made frequent television appearances on many popular variety and talk shows of the day such as The Ed Sullivan Show and The Tonight Show. She remained popular abroad, performing for fanatical crowds in the music halls of London. On April 13, 1963, a Broadway musical titled Sophie, based on Tucker's early life until 1922, opened with Libi Staiger as the lead. It closed after eight performances.

Tucker continued to perform for the rest of her life. In 1962, she performed in the Royal Variety Performance, which was broadcast on the BBC. She appeared on the Ed Sullivan Show on October 3, 1965. For the color broadcast, her last television appearance, she performed "Give My Regards to Broadway", "Louise", and her signature song, "Some of These Days".

Personal life
Tucker was married three times. Her first marriage was to Louis Tuck, a beer cart driver, with whom she eloped in 1903. The marriage produced Tucker's only child, Albert. In 1906 the couple separated, and Tucker left Albert with her family, supporting them with money from her singing jobs in New York. They were divorced in May 1913. Albert was raised by his maternal aunt, Annie. Annie and Sophie had a close relationship and kept in touch with weekly letters.

Her second marriage, to Frank Westphal (1917–20), her accompanist, and her third marriage, to Al Lackey (1928–34), her manager, both ended in divorce and produced no children. She blamed the failure of her marriages on her being too adjusted to economic independence. She said "Once you start carrying your own suitcase, paying your own bills, running your own show, you've done something to yourself that makes you one of those women men like to call 'a pal' and 'a good sport,' the kind of woman they tell their troubles to. But you've cut yourself off from the orchids and the diamond bracelets except those you buy yourself."

Tucker died of lung cancer and kidney failure on February 9, 1966, aged 80, in her Park Avenue apartment. She continued working until her death, playing shows at the Latin Quarter just weeks before. Tucker is buried in Emanuel Cemetery in Wethersfield, Connecticut.

Theatre

 * Louisiana Lou (1911–1912) (Chicago and U.S. national tour)
 * Earl Carroll's Vanities of 1924 (1924) (Broadway)
 * Leave It to Me! (1938) (Broadway and U.S. national tour)
 * High Kickers (1941–1942) (Broadway and U.S. national tour)

Film

 * Honky Tonk (1929)
 * Gay Love (1934)
 * Paramount Headliner: Broadway Highlights No. 1 (1935, short subject)
 * Broadway Melody of 1938 (1937)
 * Thoroughbreds Don't Cry (1937)
 * Follow the Boys (1944)
 * Sensations of 1945 (1944)
 * Screen Snapshots: The Great Showman (1950, short subject)
 * Screen Snapshots: Hollywood's Great Entertainers (1953, short subject)
 * The Heart of Show Business (1957, short subject)
 * The Joker Is Wild (1957)

Radio

 * Desert Island Discs, BBC radio (September 2, 1963)

Recordings

 * "Life Begins at Forty", by Jack Yellen and Ted Shapiro, recorded by Tucker in 1937.

Compilations

 * Greatest Hits (1967) (Decca DL 4942)
 * Sophie Tucker: Origins of the Red Hot Mama, 1910–1922 (Archeophone, 2009)

Influences
Tucker's comic and singing styles are credited with influencing later female entertainers, including Mae West, Rusty Warren, Carol Channing, Totie Fields, Joan Rivers, Roseanne Barr, Ethel Merman, "Mama" Cass Elliot of the Mamas & the Papas, and Bette Midler, who has included Tuck as one of her stage characters. She also influenced Miami-based radio and television host-cum-singer Peppy Fields, sister of noted pianist Irving Fields, whom Variety and Billboard magazines called the "Sophie Tucker of Miami".

Probably the greatest influence on Tucker's later song delivery was Clarice Vance (1870–1961). They appeared many times on the same vaudeville bill. Sophie made her first recordings in 1910, and Clarice made her final records in 1909. Clarice had perfected and was known for her subtle narrative talk-singing style that Sophie later used to her advantage when her vocal range became increasingly limited. At the time that Clarice Vance was using the narrative style, it was unique to her among women entertainers.

Legacy
Tucker is briefly mentioned in the lyrics of the song "Roxie" from the musical Chicago ("And Sophie Tucker'll shit I know/To see her name get billed below/Foxy Roxie Hart") and was cited as the main influence for the character Matron "Mama" Morton.

A popular music revue, Sophie Tucker: The Last of the Red Hot Mamas, developed by Florida Studio Theatre (FST) in Sarasota, Florida, celebrates Tucker's brassy and bawdy behavior, songs, and persona. Developed in-house by artistic director Richard Hopkins in 2000, it has enjoyed several productions across the country, including theatres in New York City, Chicago, Atlanta, and Toronto. Kathy Halenda, who originated the role of Tucker in the production, returned to FST for a limited engagement of The Last of the Red Hot Mamas in March 2012.

William Gazecki produced the 2014 documentary The Outrageous Sophie Tucker.

During the Beatles' appearance at the Royal Variety Performance on November 4, 1963, Paul McCartney introduced the song "Till There Was You" as having been recorded "by our favourite American group, Sophie Tucker." McCartney likewise introduced the song "I Want to Hold Your Hand" on the Ed Sullivan Show, February 16, 1964 in the same manner.

title: Sophie Tucker


text:
Weather satellite

A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting (covering the entire Earth asynchronously), or geostationary (hovering over the same spot on the equator).

While primarily used to detect the development and movement of storm systems and other cloud patterns, meteorological satellites can also detect other phenomena such as city lights, fires, effects of pollution, auroras, sand and dust storms, snow cover, ice mapping, boundaries of ocean currents, and energy flows. Other types of environmental information are collected using weather satellites. Weather satellite images helped in monitoring the volcanic ash cloud from Mount St. Helens and activity from other volcanoes such as Mount Etna. Smoke from fires in the western United States such as Colorado and Utah have also been monitored.

El Niño and its effects on weather are monitored daily from satellite images. The Antarctic ozone hole is mapped from weather satellite data. Collectively, weather satellites flown by the U.S., Europe, India, China, Russia, and Japan provide nearly continuous observations for a global weather watch.

History

As early as 1946, the idea of cameras in orbit to observe the weather was being developed. This was due to sparse data observation coverage and the expense of using cloud cameras on rockets. By 1958, the early prototypes for TIROS and Vanguard (developed by the Army Signal Corps) were created. The first weather satellite, Vanguard 2, was launched on February 17, 1959. It was designed to measure cloud cover and resistance, but a poor axis of rotation and its elliptical orbit kept it from collecting a notable amount of useful data. The Explorer VI and VII satellites also contained weather-related experiments.

The first weather satellite to be considered a success was TIROS-1, launched by NASA on April 1, 1960. TIROS operated for 78 days and proved to be much more successful than Vanguard 2. TIROS paved the way for the Nimbus program, whose technology and findings are the heritage of most of the Earth-observing satellites NASA and NOAA have launched since then. Beginning with the Nimbus 3 satellite in 1969, temperature information through the tropospheric column began to be retrieved by satellites from the eastern Atlantic and most of the Pacific Ocean, which led to significant improvements to weather forecasts.

The ESSA and NOAA polar orbiting satellites followed suit from the late 1960s onward. Geostationary satellites followed, beginning with the ATS and SMS series in the late 1960s and early 1970s, then continuing with the GOES series from the 1970s onward. Polar orbiting satellites such as QuikScat and TRMM began to relay wind information near the ocean's surface starting in the late 1970s, with microwave imagery which resembled radar displays, which significantly improved the diagnoses of tropical cyclone strength, intensification, and location during the 2000s and 2010s.

The DSCOVR satellite, owned by NOAA, was launched in 2015 and became the first deep space satellite that can observe and predict space weather. It can detect potentially dangerous weather such as solar wind and geomagnetic storms. This is what has given humanity the capability to make accurate and preemptive space weather forecasts since the late 2010s.

In Europe, the first Meteosat geostationary operational meteorological satellite, Meteosat-1, was launched in 1977 on a Delta launch vehicle. The satellite was a spin-stabilised cylindrical design, 2.1 m in diameter and 3.2 m tall, rotating at approx. 100 rpm and carrying the Meteosat Visible and Infrared Imager (MVIRI) instrument. Successive Meteosat first generation satellites were launched, on European Ariane-4 launchers from Kourou in French Guyana, up to and including Meteosat-7 which acquired data from 1997 until 2017, operated initially by the European Space Agency and later, from 1995, by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).

The Meteosat Second Generation (MSG) satellites - also spin stabilised although physically larger and twice the mass of the first generation - were developed by ESA with European industry and in cooperation with EUMETSAT who then operate the satellites from their headquarters in Darmstadt, Germany with this same approach followed for all subsequent European meteorological satellites. Meteosat-8, the first MSG satellite, was launched in 2002 on an Ariane-5 launcher, carrying the Spinning Enhanced Visible and Infrared Imager (SEVIRI) and Geostationary Earth Radiation Budget (GERB) instruments, along with payloads to support the COSPAS-SARSAT Search and Rescue (SAR) and ARGOS Data Collection Platform (DCP) missions. SEVIRI provided an increased number of spectral channels over MVIRI and imaged the full-Earth disc at double the rate. Meteosat-9 was launched to complement Meteosat-8 in 2005, with the second pair consisting of Meteosat-10 and Meteosat-11 launched in 2012 and 2015, respectively.

The Meteosat Third Generation (MTG) programme launched its first satellite in 2022, and featured a number of changes over its predecessors in support of its mission to gather data for weather forecasting and climate monitoring. The MTG satellites are three-axis stabilised rather than spin stabilised, giving greater flexibility in satellite and instrument design. The MTG system features separate Imager and Sounder satellite models that share the same satellite bus, with a baseline of three satellites - two Imagers and one Sounder - forming the operational configuration. The imager satellites carry the Flexible Combined Imager (FCI), succeeding MVIRI and SEVIRI to give even greater resolution and spectral coverage, scanning the full Earth disc every ten minutes, as well as a new Lightning Imager (LI) payload. The sounder satellites carry the Infrared Sounder (IRS) and Ultra-violet Visible Near-infrared (UVN) instruments. UVN is part of the European Commission's Copernicus programme and fulfils the Sentinel-4 mission to monitor air quality, trace gases and aerosols over Europe hourly at high spatial resolution. Two MTG satellites - one Imager and one Sounder - will operate in close proximity from the 0-deg geostationary location over western Africa to observe the eastern Atlantic Ocean, Europe, Africa and the Middle East, while a second imager satellite will operate from 9.5-deg East to perform a Rapid Scanning mission over Europe. MTG continues Meteosat support to the ARGOS and Search and Rescue missions. MTG-I1 launched in one of the last Ariane-5 launches, with the subsequent satellites planned to launch in Ariane-6 when it enters service.

In 2006, the first European low-Earth orbit operational meteorological satellite, Metop-A was launched into a Sun-synchronous orbit at 817 km altitude by a Soyuz launcher from Baikonur, Kazakhstan. This operational satellite - which forms the space segment of the Eumetsat Polar System (EPS) - built on the heritage from ESA's ERS and Envisat experimental missions, and was followed at six-year intervals by Metop-B and Metop-C - the latter launched from French Guyana in a "Europeanised" Soyuz. Each carry thirteen different passive and active instruments ranging in design from imagers and sounders to a scatterometer and a radio-occultation instrument. The satellite service module is based on the SPOT-5 bus, while the payload suite is a combination of new and heritage instruments from both Europe and the US under the Initial Joint Polar System agreement between EUMETSAT and NOAA.

A second generation of Metop satellites (Metop-SG) is in advanced development with launch of the first satellite foreseen in 2025. As with MTG, Metop-SG will launch on Ariane-6 and comprise two satellite models to be operated in pairs in replacement of the single first generation satellites to continue the EPS mission.

Observation
Observation is typically made via different 'channels' of the electromagnetic spectrum, in particular, the visible and infrared portions.

Some of these channels include:

 * Visible and Near Infrared: 0.6–1.6 μm – for recording cloud cover during the day
 * Infrared: 3.9–7.3 μm (water vapor), 8.7–13.4 μm (thermal imaging)

Visible spectrum
Visible-light images from weather satellites during local daylight hours are easy to interpret even by the average person, clouds, cloud systems such as fronts and tropical storms, lakes, forests, mountains, snow ice, fires, and pollution such as smoke, smog, dust and haze are readily apparent. Even wind can be determined by cloud patterns, alignments and movement from successive photos.

Infrared spectrum
The thermal or infrared images recorded by sensors called scanning radiometers enable a trained analyst to determine cloud heights and types, to calculate land and surface water temperatures, and to locate ocean surface features. Infrared satellite imagery can be used effectively for tropical cyclones with a visible eye pattern, using the Dvorak technique, where the difference between the temperature of the warm eye and the surrounding cold cloud tops can be used to determine its intensity (colder cloud tops generally indicate a more intense storm). Infrared pictures depict ocean eddies or vortices and map currents such as the Gulf Stream which are valuable to the shipping industry. Fishermen and farmers are interested in knowing land and water temperatures to protect their crops against frost or increase their catch from the sea. Even El Niño phenomena can be spotted. Using color-digitized techniques, the gray shaded thermal images can be converted to color for easier identification of desired information.

Types
Each meteorological satellite is designed to use one of two different classes of orbit: geostationary and polar orbiting.

Geostationary
Geostationary weather satellites orbit the Earth above the equator at altitudes of 35,880 km (22,300 miles). Because of this orbit, they remain stationary with respect to the rotating Earth and thus can record or transmit images of the entire hemisphere below continuously with their visible-light and infrared sensors. The news media use the geostationary photos in their daily weather presentation as single images or made into movie loops. These are also available on the city forecast pages of www.noaa.gov (example Dallas, TX).

Several geostationary meteorological spacecraft are in operation. The United States' GOES series has three in operation: GOES-15, GOES-16 and GOES-17. GOES-16 and-17 remain stationary over the Atlantic and Pacific Oceans, respectively. GOES-15 was retired in early July 2019.

The satellite GOES 13 that was previously owned by the National Oceanic and Atmospheric Association (NOAA) was transferred to the U.S. Space Force in 2019 and renamed the EWS-G1; becoming the first geostationary weather satellite to be owned and operated by the U.S. Department of Defense.

Russia's new-generation weather satellite Elektro-L No.1 operates at 76°E over the Indian Ocean. The Japanese have the MTSAT-2 located over the mid Pacific at 145°E and the Himawari 8 at 140°E. The Europeans have four in operation, Meteosat-8 (3.5°W) and Meteosat-9 (0°) over the Atlantic Ocean and have Meteosat-6 (63°E) and Meteosat-7 (57.5°E) over the Indian Ocean. China currently has four Fengyun (风云) geostationary satellites (FY-2E at 86.5°E, FY-2F at 123.5°E, FY-2G at 105°E and FY-4A at 104.5 °E) operated. India also operates geostationary satellites called INSAT which carry instruments for meteorological purposes.

Polar orbiting
Polar orbiting weather satellites circle the Earth at a typical altitude of 850 km (530 miles) in a north to south (or vice versa) path, passing over the poles in their continuous flight. Polar orbiting weather satellites are in sun-synchronous orbits, which means they are able to observe any place on Earth and will view every location twice each day with the same general lighting conditions due to the near-constant local solar time. Polar orbiting weather satellites offer a much better resolution than their geostationary counterparts due their closeness to the Earth.

The United States has the NOAA series of polar orbiting meteorological satellites, presently NOAA-15, NOAA-18 and NOAA-19 (POES) and NOAA-20 (JPSS). Europe has the Metop-A, Metop-B and Metop-C satellites operated by EUMETSAT. Russia has the Meteor and RESURS series of satellites. China has FY-3A, 3B and 3C. India has polar orbiting satellites as well.

DMSP
The United States Department of Defense's Meteorological Satellite (DMSP) can "see" the best of all weather vehicles with its ability to detect objects almost as 'small' as a huge oil tanker. In addition, of all the weather satellites in orbit, only DMSP can "see" at night in the visual. Some of the most spectacular photos have been recorded by the night visual sensor; city lights, volcanoes, fires, lightning, meteors, oil field burn-offs, as well as the Aurora Borealis and Aurora Australis have been captured by this 450 mi high space vehicle's low moonlight sensor.

At the same time, energy use and city growth can be monitored since both major and even minor cities, as well as highway lights, are conspicuous. This informs astronomers of light pollution. The New York City Blackout of 1977 was captured by one of the night orbiter DMSP space vehicles.

In addition to monitoring city lights, these photos are a life saving asset in the detection and monitoring of fires. Not only do the satellites see the fires visually day and night, but the thermal and infrared scanners on board these weather satellites detect potential fire sources below the surface of the Earth where smoldering occurs. Once the fire is detected, the same weather satellites provide vital information about wind that could fan or spread the fires. These same cloud photos from space tell the firefighter when it will rain.

Some of the most dramatic photos showed the 600 Kuwaiti oil fires that the fleeing Army of Iraq started on February 23, 1991. The night photos showed huge flashes, far outstripping the glow of large populated areas. The fires consumed huge quantities of oil; the last was doused on November 6, 1991.

Uses
Snowfield monitoring, especially in the Sierra Nevada, can be helpful to the hydrologist keeping track of available snowpack for runoff vital to the watersheds of the western United States. This information is gleaned from existing satellites of all agencies of the U.S. government (in addition to local, on-the-ground measurements). Ice floes, packs, and bergs can also be located and tracked from weather spacecraft.

Even pollution whether it is nature-made or human-made can be pinpointed. The visual and infrared photos show effects of pollution from their respective areas over the entire earth. Aircraft and rocket pollution, as well as condensation trails, can also be spotted. The ocean current and low level wind information gleaned from the space photos can help predict oceanic oil spill coverage and movement. Almost every summer, sand and dust from the Sahara Desert in Africa drifts across the equatorial regions of the Atlantic Ocean. GOES-EAST photos enable meteorologists to observe, track and forecast this sand cloud. In addition to reducing visibilities and causing respiratory problems, sand clouds suppress hurricane formation by modifying the solar radiation balance of the tropics. Other dust storms in Asia and mainland China are common and easy to spot and monitor, with recent examples of dust moving across the Pacific Ocean and reaching North America.

In remote areas of the world with few local observers, fires could rage out of control for days or even weeks and consume huge areas before authorities are alerted. Weather satellites can be a valuable asset in such situations. Nighttime photos also show the burn-off in gas and oil fields. Atmospheric temperature and moisture profiles have been taken by weather satellites since 1969.

Non-imaging sensors
Not all weather satellites are direct imagers. Some satellites are sounders that take measurements of a single pixel at a time. They have no horizontal spatial resolution but often are capable or resolving vertical atmospheric layers. Soundings along the satellite ground track can still be gridded later to form maps.

International regulation

According to the International Telecommunication Union (ITU), a  meteorological-satellite service (also: meteorological-satellite radiocommunication service) is – according to Article 1.52 of the ITU Radio Regulations (RR) – defined as « An earth exploration-satellite service for meteorological purposes.»

Classification
This radiocommunication service is classified in accordance with ITU Radio Regulations (article 1) as follows:

Fixed service (article 1.20)
 * Fixed-satellite service (article 1.21)
 * Inter-satellite service (article 1.22)
 * Earth exploration-satellite service (article 1.51)
 * Meteorological-satellite service

Frequency allocation
The allocation of radio frequencies is provided according to Article 5 of the ITU Radio Regulations (edition 2012).

In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which is with-in the responsibility of the appropriate national administration. The allocation might be primary, secondary, exclusive, and shared.
 * primary allocation: is indicated by writing in capital letters (see example below)
 * secondary allocation: is indicated by small letters
 * exclusive or shared utilization: is within the responsibility of administrations

 * Example of frequency allocation:

title: Weather satellite