In 1932, a Soviet expedition on the icebreaker "A. Sibiryakov" led by Professor Otto Yulievich Schmidt was the first to sail all the way from Arkhangelsk to the Bering Strait in the same summer without wintering en route. After trial runs in 1933 and 1934, the "Northern Sea Route" was officially defined and open and commercial exploitation began in 1935. The next year, part of the Baltic Fleet made the passage to the Pacific where armed conflict with Japan was looming.