LOUISVILLE – Sierra Nevada has NASA’s okay for its Dream Chaser spacecraft’s first mission.

NASA issued what’s called an Authority to Proceed this week, setting Dream Chaser's first launch window for late 2020. Sierra Nevada will build the spaceship in Louisville, where concepts and dreams are turning into deadlines.

Dream Chaser's first mission will be to resupply the International Space Station. For Sierra Nevada, the goal will be to prove the reliability of what engineers in Colorado have been working on for years.

The unmanned cargo version of the Dream Chaser will not have any windows.

"In our vision, spaceships should have wings and come back to a runway,” Sierra Nevada’s principal systems engineer Kathy Benzini said. “The space shuttle introduced a new era of spacecraft and we'd like to continue that going forward towards the future, instead of looking back to some of our older designs.”

Dream Chaser will be the only vehicle flying to and from the ISS that has wings and lands on a runway like an airplane. It’s a gentle landing compared to other spacecraft used today.

“What it means is that we can bring cargo back to a runway and give it to the scientific providers as soon as possible, within hours of our landing,” Benzini said. “There aren’t any shocks that the science equipment would experience.”

The Dream Chaser - manned version - can carry up to 7 people.

Sierra Nevada said each Dream Chaser will be able to fly at least 15 missions. And it can land on any commercial runway, anywhere in the world. The cargo-only version has no windows and includes a cargo module on the tail end of the vehicle.

If NASA approves manned missions for Dream Chaser, the spacecraft could carry up to seven people. For now, just getting to launch day at the Kennedy Space Center in Florida would be a dream come true.

“I think to actually see our vehicle fly will be just an unbelievable experience," Benzini said.