NASA and the U.S. Department of Energy awarded three US$5 million contracts to produce reactor design concepts that could one day be used to transport people and cargo to Mars.

Nuclear energy has fallen out of favor in most parts of the world, but when it comes to outer space, the sky is the limit.

The U.S. government is using the expertise of Jeff Bezos’ Blue Origin space company, GE Hitachi Nuclear Energy and other companies to develop nuclear-powered spacecraft that can fly faster and farther—to Mars and Farther away.

NASA said in a statement on Tuesday that NASA and the Department of Energy have awarded three contracts worth $5 million to produce reactor design concepts that can be used to transport people and goods to Mars or transport science The mission is advanced to the outer solar system.

Defense contractors Lockheed Martin and Aerojet Rocketdyne Holdings Inc., as well as drone manufacturer General Atomics and BWX Technologies Inc., which produces nuclear components and fuel, are all involved in this work.

“These design contracts are an important step towards tangible reactor hardware that can one day advance new missions and exciting discoveries,” said Jim Royt, deputy director of NASA’s Space Technology Mission Directorate, in a statement.

According to the National Aeronautics and Space Administration, nuclear propulsion systems are more effective than standard chemical rockets, which means they are expected to perform more ambitious missions faster and deeper into space.

At the same time, nuclear energy now generates about 10% of the world’s electricity, down from the peak of 18% in the mid-1990s.

It may take several years to develop space travel technology, which faces major obstacles. Although nuclear power plants have been used on submarines and aircraft carriers for decades, placing them on explosive rockets poses significant risks.

Nuclear space efforts coincide with the resurgence of extraterrestrial activities, and the US government is exploring Mars and planning the first manned mission to the moon in decades.

At the same time, companies backed by celebrity billionaires are racing to commercialize space tourism.

Virgin Galactic Holdings completed a suborbital test flight with founder Richard Branson on Sunday.

Amazon founder Bezos plans to fly into space on a rocket made by Blue Origin next week.

General Electric Company built many reactors from the 1970s and 1980s that derive energy from boiling water, and these reactors are still the core of the US nuclear energy product portfolio.

Recently, the company has focused on small reactors that do not require the same infrastructure through a joint venture with Hitachi Co., Ltd. Due to cost overruns and strong opposition after the Fukushima nuclear accident in Japan, the development and interest in larger nuclear power has slowed in recent years and collapsed in 2011.