In 1918 Amundsen sailed in the ship Maud to study the Arctic, hoping to freeze the ship into the ice and drift like an earlier explorer did. The Maud became stuck many times near places such as the New Siberian Islands and Wrangel Island. The crew spent several winters trapped, and Amundsen was hurt when he broke his arm and had a dangerous encounter with a polar bear. The ship reached Seattle for repairs in 1921.
Amundsen also tried flying in the Arctic. In 1923 a plane trip failed, but in 1925 he flew to 87°44′ north with flying boats. In 1926 he flew over the North Pole in the airship Norge, a trip that may be the first clearly proven crossing of the Pole. Scientists on the Maud collected valuable data, and some records were later recovered. These journeys mixed brave exploration, hard winters, and some disputes about who reached the Pole first.