NASA astronaut and Commercial Crew member Sunita Williams in March 2018. NASA/Kim Shiflett

After nearly a decade of effort, SpaceX and Boeing are preparing to launch the first NASA astronauts on commercial spaceships.

On August 3, NASA announced the first nine astronauts who will risk their lives on the first crewed missions of Boeing's CST-100 Starliner and SpaceX's Crew Dragon spacecraft in 2019.

The goal of NASA's Commercial Crew program, as it's called, is to taxi astronauts to and from the $150-billion International Space Station (ISS). Accomplishing that would close an increasingly expensive gap in the US' space-travel capabilities.

In 2015, NASA selected astronaut Sunita "Suni" Williams and three other "space pioneers" to test then fly the new spaceships.

Williams is slated to fly aboard Boeing's second test flight to the ISS.

"Five years ago, this would have been like, 'No way, what are we doing asking commercial providers to be able to do this?'" Williams told Business Insider in June. "Now it feels like a natural progression for space travel."

Williams has flown inside three spaceships, served as commander of the International Space Station, lived in orbit for 322 days, and piloted 30 different types of aircraft for the Navy.

This extensive resume has come in handy over the past three years, as Williams has worked closely with Boeing and SpaceX. She and her colleagues have poked and prodded spacecraft mock-ups, tried on new spacesuits, fiddled with control panels, tested out simulators, and provided frank and sometimes critical feedback.

Here's why NASA needs Boeing and SpaceX, what Williams thinks of their new ships and suits, and how she's preparing to blast off into the uncharted territory of a new space race.

This story was updated with new information. It was originally published on June 24, 2018.