Boeing is hot on the heels of SpaceX as the aerospace company readies to send its own human-rated spacecraft into orbit.

>> Read more trending news

The first-stage booster for Boeing's first manned launch of its CST-100 Starliner spacecraft arrived at Florida's Space Coast on Wednesday.

This modern-day American space race is heating up as both companies position to be the first to send astronauts back to space from American soil.

When Boeing attempts Starliner’s first flight, it will be on a United Launch Alliance rocket and officials are saying its first manned mission to space is not far away.

If everything goes smoothly over the next few months, ULA and Boeing will conduct unmanned test flights, with a possibility of a flight with crew members on-board by December.

“We haven't seen this kind of stuff happen until the space shuttle program ended,” said Josh Barrett with Boeing. “So the whole Boeing, NASA, United Launch Alliance team is just excited to see this hardware show up. And it's just feeling real.”

The first-stage booster of the Atlas 5 rocket was hauled to a hangar at the Space Operations Center until it's ready to launch Starliner.

Atlas 5 is touted by ULA as its "space taxi" to the International Space Station.

Returning to manned launches is a major milestone for NASA, after years of funding and technical setbacks for both Boeing and competitor SpaceX.

“There's a flag up there to bring back,” said Ken Kremer with Space Upclose. “Both companies, pushing to be first to get astronauts back to the space station, and to do it safely.”

Starliner's first un-crewed test flight is set for late August.