Posted: Tue, Jun 17, 2014, 2:14 PM ET (1814 GMT)

United Launch Alliance (ULA) said Monday that it has signed contracts with "multiple" US companies to study designs for a new engine that could replace the Atlas 5's RD-180. ULA said those contracts, with companies it declined to name, will cover feasibility analysis of the proposed engines as well as schedule, cost, and technical risks. ULA said it is also working with RD AMROSS, the US-Russian joint venture that provides the RD-180 engines for ULA, on long-term solutions that could include US production of the engine. In the statement, ULA said it plans to select an engine design in the fourth quarter of this year and have that engine ready for service by 2019. The future of the RD-180 has been in question since earlier this year, when Russian officials indicated that it would ban the use of the engine for launches of military payloads. ULA and other industry and government officials have said in the following weeks that Russia has made no attempt to ban or restrict access to the RD-180. Congress is, though, considering legislation that would call for a "full and open competition" to develop a replacement engine, providing as much as $220 million towards that effort for fiscal year 2015.