Factbox: U.S. Air Force maps out plan to replace Russian rocket motor

WASHINGTON (Reuters) - The U.S. Air Force on Tuesday mapped out a four-step plan to end U.S. reliance on Russian-built rocket engines for launching key military and intelligence satellites. Air Force acquisition chief William LaPlante said the service hoped to get approval from the Pentagon in coming weeks for an approach that would leverage both government and private investment in new propulsion systems. LaPlante provided the Air Force's most detailed glimpse yet into its acquisition strategy for a program that offers opportunities to the United Launch Alliance, a joint venture of Lockheed Martin Corp and Boeing Co, privately held Space Exploration Technologies, or SpaceX, GenCorp Inc's Aerojet Rocketdyne unit, and Orbital ATK. - First, the Air Force would use fiscal 2014 and 2015 funding to complete technology work already under way by NASA and the Air Force Research Laboratory that is aimed at improving combustion stability in a high-performance engine. That technology work would be made available to industry. - Second, the Air Force would use the remainder of $220 million in funding from the fiscal 2015 budget to partner with companies as they worked on new rocket propulsion systems, with any resulting technology to be available to any launch provider. - In a third step, the Air Force would invest in U.S.-powered launch systems, beginning with fiscal 2016 funds, with a goal of eventually having two or more systems that are available for government or commercial launches. - Finally, the Air Force said it planned a full and open competition for national security launches to occur between 2020 and 2024, initially using existing systems but transitioning to the newly developed systems once they were certified. (Reporting by Andrea Shalal; Editing by Ken Wills)