Meet the veteran astronauts riding aboard Starliner’s historic first crewed launch Saturday

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After multiple delays, the highly anticipated inaugural crewed launch of Boeing’s Starliner is “go” for launch on Saturday — and the new spacecraft will be carrying a duo of veteran astronauts.

Liftoff of Boeing’s Crew Flight Test mission is scheduled for 12:25 p.m. ET from Cape Canaveral Space Force Station in Florida. If all goes according to plan, the mission will deliver NASA’s Butch Wilmore and Suni Williams to the International Space Station. After eight days, they will return to Earth in the reusable crew capsule, landing at a location in the southwestern United States.

The launch will stream live on NASA’s website Saturday, with coverage beginning at 8:15 a.m. ET.

If the spacecraft does not liftoff as planned atop an Atlas V rocket, there are backup opportunities available on June 2, June 5 and June 6, according to NASA.

Williams and Wilmore were in their seats aboard Starliner on May 6, only about two hours from a historic launch when engineers identified an issue with a valve on the second stage, or upper portion, of the Atlas V rocket. The entire stack, including the rocket and spacecraft, was then rolled back from the launchpad for testing and repairs.

Then, mission teams reported a small helium leak within the spacecraft service module. The leak was traced to a part called a flange on a single reaction control system thruster, where helium is used to allow the thrusters to fire and propel the spacecraft.

The space agency said the leak does not pose a threat to a mission, but while evaluating the issue, engineers also spotted a “design vulnerability” in the propulsion system — essentially identifying a remote scenario in which certain thrusters might fail as the vehicle was leaving Earth’s orbit, without a backup method of getting home safely.

NASA and Boeing have since worked with the vendor of the thruster to come up with a backup way to perform the deorbit burn, should that situation arise, said Steve Stich, manager of NASA’s Commercial Crew Program, in a May 24 news conference.

After a flight readiness review meeting on May 29, leaders from NASA, Boeing and United Launch Alliance (which built the rocket) “verified launch readiness, including all systems, facilities, and teams supporting the test flight,” according to NASA.

Williams and Wilmore, who have remained in a standard crew quarantine to protect their health prior to the launch attempt, returned to Houston on May 10 to spend time with their families, according to Boeing. While there, the astronauts also practiced for their flight in Starliner simulators, according to NASA.

The duo returned to NASA’s Kennedy Space Center on May 28, continuing their quarantine at the Neil A. Armstrong Operations and Checkout Building ahead of liftoff.

Suni Williams: Already in the history books

Saturday’s launch of the Starliner would mark only the sixth maiden voyage of a crewed spacecraft in US history, NASA Administrator Bill Nelson noted in a news conference earlier this month.

“It started with Mercury, then with Gemini, then with Apollo, the space shuttle, then (SpaceX’s) Dragon — and now Starliner,” he said.

For Starliner’s debut launch, NASA is sticking with a long tradition of staffing the novel spacecraft with astronauts who have previously trained as military test pilots and spent hours flying experimental aircraft.

“They’re checking out a lot of the systems: the life support, the manual control,” NASA chief Bill Nelson said during a May 3 news conference. “That’s why we put two test pilots on board — and of course the resumes of Butch and Suni are extensive.”

Williams, selected as a NASA astronaut in 1998, will also make history as the first woman to embark on such a mission. And it won’t be her first entry in the history books.

In 2012, during a prior trip to the International Space Station, Williams became the first person to finish a triathlon in space, during which she simulated swimming using a weight-lifting machine and ran on a treadmill while strapped in by a harness so she wouldn’t float away.

That came after she ran the Boston Marathon from the space station in 2007.

Williams — a native of Needham, Massachusetts — has also spent ample time outside the space station.

During her previous missions, she notched a total of 50 hours and 40 minutes across seven spacewalks, ranking second among female astronauts.

Ahead of this mission, Williams told reporters that she wasn’t nervous about making the jump from test piloting aircraft to spacecraft.

“I don’t necessarily think it’s jitters,” she said. “I’m just thinking it’s more like last-minute checks — crossing the t’s dotting the i’s.”

Williams has traveled to space twice before, once on a NASA space shuttle in 2006 and again on a Russian Soyuz capsule in 2012. She’s logged 322 total days in space.

Wilmore: ‘You can endeavor to do anything’

Meanwhile, Wilmore — a Tennessee native and Navy test pilot — has spent more than 8,000 hours of his life aboard tactical jets, according to NASA.

Before he was selected for NASA’s astronaut corps in 2000, Wilmore was on exchange as flight test instructor at the Air Force Test Pilot School in California.

As an astronaut, Wilmore has already logged 178 days in space during two separate missions and conducted four spacewalks.

Wilmore once recounted a spacewalk experience while giving an acceptance speech for the NCAA Theodore Roosevelt Award in 2018. (Wilmore played football at Tennessee Technological University as an undergrad.)

He said that, during the spacewalk, he was surprised to find that a radiator on the space station’s exterior was reflective, like a mirror.

“All of a sudden, for the first time ever, I see me in a spacesuit from head to toe. … I look back at that guy and I said, ‘How did you get here?’” Wilmore said. “If you have a pulse, that’s all that’s required. You can endeavor to do anything you want to do.”

CNN’s Deblina Chakraborty contributed to this report.

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