Blue Origin

But Blue Origin isn't the only company working on taking back America's role as a leader in rocket propulsion systems.

In direct competition is the rocket propulsion manufacturer company Aerojet Rocketdyne, which just got a major vote of confidence.

The rest of that $738 million the Air Force is willing to invest — which equates to a whopping $536 million — was dedicated to Aerojet Rocketdyne.

Right now, Aerojet is constructing its AR1 rocket engine, which the company says could be used to propel the Atlas V, Vulcan, as well as other rockets currently under development.

While ULA has contracted with Blue Origin to build its BE-4 rocket engines for the Vulcan rocket, ULA also has a contract with Aerojet, as back up.

If Blue Origin's efforts to build the BE-4 rocket engine falter, then ULA will turn to Aerojet's AR1 to power the Vulcan.

ULA and Aerojet have until Dec. 31, 2019 to design, build, and test its new engines.

"While the RD-180 engine has been a remarkable success with more than 60 successful launches, we believe now is the right time for American investment in a domestic engine," Tory Bruno, ULA's president and chief executive officer, said in a release.