Editing UGM-27 Polaris (section)

=== Project Nobska ===
{{Main|Project Nobska}}
The U.S. Navy began work on nuclear-powered submarines in 1946. They launched the first one, the [[USS Nautilus (SSN-571)|USS Nautilus]] in 1955. Nuclear powered submarines were the least vulnerable to a first strike from the Soviet Union. The next question that led to further development was what kind of arms the nuclear-powered submarines should be equipped with.<ref>Istvan Hargittai. p. 357. ''Judging Edward Teller: A Closer Look at One of the Most Influential Scientists of the Twentieth Century'' {{ISBN?}}</ref> In the summer of 1956, the navy sponsored a study by the National Academy of Sciences on anti-submarine warfare at Nobska Point in Woods Hole, Massachusetts, known as [[Project Nobska|Project NOBSKA]]. The navy's intention was to have a new missile developed that would be lighter than existing missiles and cover a range up to fifteen hundred miles. A problem that needed to be solved was that this design would not be able to carry the desired one-megaton thermonuclear warhead.

This study brought [[Edward Teller]] from the recently formed nuclear weapons laboratory at Livermore and [[J. Carson Mark]], representing the Los Alamos nuclear weapons laboratory. Teller was already known as a nuclear salesman, but this became the first instance where there was a big betting battle where he outbid his Los Alamos counterpart. The two knew each other well: Mark was named head of the theoretical division of Los Alamos in 1947, a job that was originally offered for Teller. Mark was a cautious physicist and no match for Teller in a bidding war.<ref>Istvan Hargittai. p. 358. ''Judging Edward Teller: A Closer Look at One of the Most Influential Scientists of the Twentieth Century''</ref>

At the NOBSKA summer study, Edward Teller made his famous contribution to the FBM program. Teller offered to develop a lightweight warhead of one-megaton strength within five years. He suggested that nuclear-armed torpedoes could be substituted for conventional ones to provide a new anti-submarine weapon. Livermore received the project. When Teller returned to Livermore, people were astonished by the boldness of Teller's promise. It seemed inconceivable with the current size of nuclear warheads, and Teller was challenged to support his assertion. He pointed out the trend in warhead technology, which indicated reduced weight to yield ratios in each succeeding generation.<ref name="ReferenceA">Graham Spinardi. p. 30. ''From Polaris to Trident: The Development of U.S. Fleet Ballistic Missile Technology'' {{ISBN?}}</ref> When Teller was questioned about the application of this to the FBM program, he asked, ‘Why use a 1958 warhead in a 1965 weapon system?’<ref>William F. Whitmore, Lockheed Missiles and Space Division (Whitemore 1961, p. 263)</ref>

Mark disagreed with Teller's prediction that the desired one-megaton warhead could be made to fit the missile envelope within the timescale envisioned. Instead, Mark suggested that half a megaton would be more realistic and he quoted a higher price and a longer deadline. This simply confirmed the validity of Teller's prediction in the Navy's eyes. Whether the warhead was half or one megaton mattered little so long as it fitted the missile and would be ready by the deadline.<ref name="ReferenceA" /> Almost four decades later, Teller said, referring to Mark's performance, that it was “an occasion when I was happy about the other person being bashful.”<ref name="ReferenceA" />
When the Atomic Energy Commission backed up Teller's estimate in early September, Admiral Burke and the Navy Secretariat decided to support SPO in heavily pushing for the new missile, now named Polaris by Admiral Raborn.

There is a contention that the Navy's "Jupiter" missile program was unrelated to the Army program. The Navy also expressed an interest in Jupiter as an SLBM, but left the collaboration to work on their Polaris. At first, the newly assembled SPO team had the problem of making the large, liquid-fuel Jupiter IRBM work properly. Jupiter retained the short, squat shape intended to fit in naval submarines. Its sheer size and volatility of its fuel made it very unsuited to submarine launching and was only slightly more attractive for deployment on ships. The missile continued to be developed by the Army's German team in collaboration with their main contractor, Chrysler Corporation. SPO's responsibility was to develop a sea-launching platform with necessary fire control and stabilization systems for that very purpose. The original schedule was to have a ship-based IRBM system ready for operation evaluation by January 1, 1960, and a submarine-based one by January 1, 1965.<ref>Graham Spinardi. p. 27. ''From Polaris to Trident: The Development of US Fleet Ballistic Missile Technology'' {{ISBN?}}</ref>
However, the Navy was deeply dissatisfied with the liquid fuel IRBM. The first concern was that the cryogenic liquid fuel was not only extremely dangerous to handle, but launch-preparations were also very time-consuming. Second, an argument was made that liquid-fueled rockets gave relatively low initial acceleration, which is disadvantageous in launching a missile from a moving platform in certain sea states. By mid-July 1956, the Secretary of Defense's Scientific Advisory Committee had recommended that a solid-propellant missile program be fully instigated but not using the unsuitable Jupiter payload and guidance system.
By October 1956, a study group comprising key figures from Navy, industry and academic organizations considered various design parameters of the Polaris system and trade-offs between different sub-sections. The estimate that a 30,000-pound missile could deliver a suitable warhead over 1500 nautical miles was endorsed. With this optimistic assessment, the Navy now decided to scrap the Jupiter program altogether and sought out the Department of Defense to back a separate Navy missile.<ref>Graham Spinardi. p. 28. ''From Polaris to Trident: The Development of US Fleet Ballistic Missile Technology''</ref>
A huge surfaced submarine would carry four "Jupiter" missiles, which would be carried and launched horizontally.<ref>[https://www.usna.com/NetCommunity/SSLPage.aspx?pid=659&srcid=502 1946:1<!-- Bot generated title -->]{{dead link|date=December 2016}}</ref> This was probably the never-built [[SSM-N-2 Triton]] program.<ref>Friedman, p. 183</ref> However, a history of the Army's Jupiter program states that the Navy was involved in the Army program, but withdrew at an early stage.<ref name="heroicrelics.org" />

Originally, the Navy favored cruise missile systems in a strategic role, such as the [[Regulus missile]] deployed on the earlier {{USS|Grayback|SSG-574|6}} and a few other submarines, but a major drawback of these early cruise missile launch systems (and the Jupiter proposals) was the need to surface, and remain surfaced for some time, to launch. Submarines were very vulnerable to attack during launch, and a fully or partially fueled missile on deck was a serious hazard. The difficulty of preparing a launch in rough weather was another major drawback for these designs, but rough sea conditions did not unduly affect Polaris' submerged launches.

It quickly became apparent that solid-fueled ballistic missiles had advantages over cruise missiles in range and accuracy, and could be launched from a submerged submarine, improving submarine survivability.

The prime contractor for all three versions of Polaris was [[Lockheed Missiles and Space Company]] (now [[Lockheed Martin]]).
[[File:1960-07-21 First Polaris Firing By Submerged U-Boat.ogv|thumb|thumbtime=57|Universal International Newsreel of first Polaris submerged firing on 20 July 1960]]
The Polaris program started development in 1956. {{USS|George Washington|SSBN-598|6}}, the first U.S. missile submarine, successfully launched the first Polaris missile from a submerged submarine on July 20, 1960. The A-2 version of the Polaris missile was essentially an upgraded A-1, and it entered service in late 1961. It was fitted on a total of 13 submarines and served until June 1974. Ongoing problems with the [[W47|W-47 warhead]], especially with its mechanical arming and safing equipment, led to large numbers of the missiles being recalled for modifications, and the U.S. Navy sought a replacement with either a larger yield or equivalent destructive power. The result was the [[W58|W-58 warhead]] used in a "cluster" of three warheads for the Polaris A-3, the final model of the Polaris missile.

One of the initial problems the Navy faced in creating an SLBM was that the sea moves, while a launch platform on land does not. Waves and swells rocking the boat or submarine, as well as possible flexing of the ship's hull, had to be taken into account to properly aim the missile.

The Polaris development was kept on a tight schedule and the only influence that changed this was the USSR's launching of [[Sputnik]] on October 4, 1957.<ref name=":2" /> This caused many working on the project to want to accelerate development. The launch of a second Russian satellite and pressing public and government opinions caused Secretary Wilson to move the project along more quickly.<ref name=":2" />

The Navy favored an underwater launch of an IRBM, although the project began with an above-water launch goal. They decided to continue the development of an underwater launch, and developed two ideas for this launch: wet and dry. Dry launch meant encasing the missile in a shell that would peel away when the missile reached the water's surface.<ref name=":2" />  Wet launch meant shooting the missile through the water without a casing.<ref name=":2" /> While the Navy was in favor of a wet launch, they developed both methods as a failsafe.<ref name=":2" /> They did this with the development of gas and air propulsion of the missile out of the submerged tube as well.

The first Polaris missile tests<ref name=":2" /> were given the names “AX-#” and later renamed “A1X-#”. Testing of the missiles occurred:

*September 24, 1958: AX-1, at Cape Canaveral from a launch pad; the missile was destroyed, after it failed to turn into the correct trajectory following a programming-error.

*October 1958: AX-2, at Cape Canaveral from a launch pad; exploded on the launch pad.

*December 30, 1958: AX-3, at Cape Canaveral from a launch pad; launched correctly, but was destroyed because of the fuel overheating.

*January 19, 1959: AX-4, at Cape Canaveral from launch pad: launched correctly but began to behave erratically and was destroyed.

*February 27, 1959: AX-5, at Cape Canaveral from launch pad: launched correctly but began to behave erratically and was destroyed.

*April 20, 1959: AX-6, at Cape Canaveral from launch pad: this test was a success. The missile launched, separated, and splashed into the Atlantic 300 miles off shore.

It was in between these two tests that the inertial guidance system was developed and implemented for testing.

*July 1, 1959: AX-11 at Cape Canaveral from a launch pad: this launch was successful, but pieces of the missile detached causing failure. It did show that the new guidance systems worked.