In 1941 before the US entered World War II, US authorities seized her and started converting her into a United States Navy stores ship.

Arauca was one of three sister ships that Bremer Vulkan of Bremen-Vegesack, Germany built in 1939 for Hamburg Amerikanische Paketfahrt AG (HAPAG).

[2] German merchant ships now risked being seized or sunk by the Royal Navy, so Arauca remained in port for the next two and a half months.

[2][3] On 6 July 1941 US Presidential Executive Order 101 authorised the United States Maritime Commission to take over foreign ships lying idle in US ports.

[2] On 28 July 1941 the Commission took over Arauca and contracted her management to the South Atlantic Steamship Company of Savannah, Georgia,[2] which renamed her SS Sting.

[2] There both the Maritime Commission and the South Atlantic SS Co concluded that they did not have engine-room crews skilled enough to run her transmission and high-pressure boilers, so on 14 November they offered her to the US Navy Auxiliary Vessels Board.

[2] From March 1943 Saturn operated between east coast ports, mainly Norfolk, Virginia, and Baltimore, Maryland, and bases in the Caribbean such as Guantanamo and Trinidad.

[3] She was laid up in the National Defense Reserve Fleet in the James River, Virginia until 12 September 1972, when she was sold to Isaac Varela of Castellón de la Plana, Spain for scrap.