PFS Polarstern (meaning pole star) is a German research icebreaker of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven. The Polarstern was put into commission in 1982 and is mainly used for research in the Arctic and Antarctica.
Polarstern was built by the Howaldtswerke/Deutsche Werft at Kiel and the Werft Nobiskrug at Rendsburg. The ship has a length of 118 metres (387 feet).
Polarstern is a double-hulled icebreaker. It is operational at temperatures as low as -50 °C. (-58°F) Polarstern can break through ice 1.5 metres thick at a speed of 5 knots. Thicker ice must be broken by ramming.