United Space Alliance (USA) was a spaceflight operations company. USA was a joint venture which was established in August 1995 as a Limited Liability Company (LLC), equally owned by Rockwell International and Lockheed Martin. The sale of Rockwell's aerospace and defense assets, including the Rockwell Space Operations Company (RSOC) and the Space Transportation System Operations Contract (STSOC) to Boeing in December 1996 made Boeing the co-owner along with Lockheed for the rest of the company's corporate existence.