Blue Origin, a private space company owned by Mr. Bezos, said on Wednesday that it had agreed to work with a joint venture run by Boeing and Lockheed Martin to build new engines for their Atlas 5 rockets.

That venture, called United Launch Alliance, has sent nearly all United States spy and military satellites into space in the last decade, but a rise in tensions with Russia this year after its annexation of Crimea has forced the venture to look for a replacement. In May, Russia threatened to stop delivering the engines, known as RD-180s, in response to American sanctions against top Russian officials, though there has been no evidence yet that it will follow through.

News that Blue Origin would assume a bigger role in space launches came as NASA on Tuesday announced it had picked Boeing and SpaceX to ferry astronauts to the International Space Station and replace the retired space shuttle program. Boeing plans to use Atlas 5 rockets for its manned spacecraft, while SpaceX will use its existing rocket, the Falcon 9, to propel its new capsule. The first flights could take place as early as 2017.

By working with Blue Origin to build new American-made engines, Boeing and Lockheed sidestep the politically sensitive issue of the Russian RD-180 engines on the Atlas 5 for NASA and military missions in the future.