As the second half of the 20th century arrived, the United States had been at peace for 5 years, and the Navy  was  involved  in  many  scientific  pursuits. However,  scientific  and  exploratory  pursuits  were interrupted by the outbreak of the Korean Conflict. THE KOREAN CONFLICT Supported by the United Nations, the United States agreed to give the Republic of Korea air and naval assistance.  Three  days  after  that  decision,  June  29, 1950, the cruiser USS  Juneau  and the destroyer USS Dehaven  fired the first shots of the war. When  North  Korea  attacked  south  of  the  38th parallel, the Navy was called on for close air support to knock out bridges and block enemy supply routes. Navy jets  flew  from  carriers  for  the  first  time  in  a  war situation. Unlike World War II, the enemy didn’t have the capability to strike our carriers, so pilots launched their  Corsairs  and  Banshees  on  the  first  sustained ground-support missions in history. The helicopter also came of age during the Korean Conflict. First studied and developed in 1942 when the Navy  received  four  Sikorskys,  the  choppers  were spotters for artillery. In Korea, they flew emergency supply runs and took part in direct combat duties. Later, the helicopter was used as a cargo transport between ships  during  underway  replenishment,  search  and rescue missions, and ASW exercises. Korea was the testing  ground  for  the  helicopter  and  many  other innovations our forces currently use. On  September  15,  1950,  under  massive  shore bombardment  by  U.S.  Navy  ships,  the  amphibious landings at Inchon began. The successful operation cut enemy  communications,  split  enemy  forces,  and dissolved enemy resistance in that area. The shelling of supply roads far inland by the battleship USS  Missouri demonstrated a new tactical concept. That concept was the Navy’s ability to intervene successfully in a ground operation far ashore. The Korean Conflict (fig. 5-13 and fig. 5-14) lasted until July 1953. Other events were happening in the Navy while the war was being waged. For example, a program was established giving outstanding enlisted women the opportunity to receive commissions in the Regular Navy. KOREA TO VIETNAM The 1950s was a time of change. By the end of the decade,  most  operational  aircraft  in  the  attack  and fighter arsenals of the sea service were jets. More and more angled-deck carriers were authorized, and new deck-edge elevators allowed simultaneous takeoffs and landings. The USS Nautilus, the first nuclear submarine, was first put to sea on January 17, 1955. Under Commander Eugene P. Wilkinson, the USS  Nautilus  transmitted the historic signal, “Underway on nuclear power.” On its shakedown  cruise  in  May  1955,  the  USS   Nautilus steamed submerged from New London, Connecticut, to San Juan, Puerto Rico. It traveled over 1,300 miles in 84 hours—a distance 10 times greater than the record for continuously  submerged  travel  by  any  previous submarine. After more than 2 years of operation and evaluation, the USS Nautilus was refueled in April 1957. On its first nuclear core, it steamed a total of 62,562 miles; it made more than half of that cruise while totally submerged. A conventionally powered submarine the size of the USS Nautilus  would have required over 2 million gallons of fuel oil to duplicate that feat. A train of tank cars over a mile and a half long would have been necessary to transport that amount of fuel. On August 12, 1958, the USS Nautilus completed a history-making transpolar voyage from Pearl Harbor, Hawaii, to Portland, England. After diving under the ice near  Point  Barrow,  Alaska,  on  August  1,  1958,  it became the first submarine to reach the geographic North Pole. Nuclear  submarines  produced  after  the  USS Nautilus  continued to pioneer new areas of submarine operations.  The  USS    Seawolf,  the  Navy’s  second nuclear-powered submarine, operated as an active unit of the Atlantic Fleet. On October 6, 1958, it completed a record-breaking  60-day  run,  traveling  a  distance  of 13,761 miles submerged. While  the  USS    Nautilus    was  still  undergoing operational testing, the Navy began development of a ballistic missile of intermediate range. Brought from conception to initial operation in 5 years’ time, the Polaris fleet ballistic missile (FBM) weapons system 5-25 Student Notes: