The U.S. Air Force has awarded $160 million worth of contracts to two companies on Monday. These two firms are engaged in the development of the latest rocket engines and will help the United States end its dependence on Russian-made rocket motors for the country's space launches.

The bigger contract, amounting to $115 million, was awarded to Aerojet Rocketdyne Holdings Inc. It is tasked to develop its AR1 rocket propulsion system prototype.

The other contract worth $46.6 million was awarded to United Launch Alliance, a company based in Centennial, Colorado, together with Blue Origin, a startup owned by the Washington-based Amazon.com.

These contracts are part of the U.S. Air Force top priority space acquisitions for 2016.

ULA will spend the money in developing a prototype of its Vulcan launch vehicle using the BE-4 engine. It will also start working on the company's next generation upper stage engine called the Advanced Cryogenic Evolved Stage (ACES).

These current developments were induced by the 2014 Crimean crisis where Russia annexed Crimea on March 21, 2014 after it declared its independence from Ukraine on March 11 of the same year.

Congress instructed the Defense Department to develop its own domestic propulsion system which would allow the Air Force to terminate its dependence on the RD-180 engine built by Russia, by 2019.

This particular engine powers the Atlas 5 rocket made by ULA, the rocket that is used in launching most of the country's national security satellites.

The contract is a victory for Aerojet and will help it to recover from a big setback in 2015 when ULA, one of its major clients, suddenly announced that it is switching to solid rocket boosters produced by Orbital ATK after 2018.

"Having two or more domestic, commercially viable launch providers that also meet national security space requirements continues to be our end goal," said Lt. Gen. Samuel Greaves, commander of the Air Force's Space and Missile Systems Center in a press release.