MERRITT ISLAND, Florida -- Retired astronaut Peggy Whitson is heading back into space on Sunday.
NASA officials say the weather looks favorable for the afternoon launch of the Space-X Dragon from the Kennedy Space Center.
"Really the only thing we're going to have to watch for is the anvil coming off the top of those thunderstorms," Brian Cizek said.
Whitson will be joined by some paying customers. Their journey, put together by the Houston-based company Axiom, will be the second all-private mission to the orbiting outpost.
The mission, called AX-2, will also make history as stem cell researcher Rayyanah Barnawi is set to become the first woman from Saudi Arabia to travel to space.
A live stream of the launch will begin at 4:30 p.m. ET Sunday, with liftoff expected at 5:37 p.m. ET from NASA's Kennedy Space Center in Florida.
This mission is the next in a lineup of flights that Axiom Space and NASA hope will continue to spur private sector participation in spaceflight - particularly in low Earth orbit, where the space station lies.
Whitson, 63 is now an Axiom employee. With this mission, Whitson will become the first woman to command a private spaceflight.
She also holds the record for the number of days in space and most spacewalks by a woman.
Joining her will be three paying customers, including John Shoffner, an American who made his fortune in the international telecom business and founded the hardware company Dura-Line Corp.
Saudi Arabia also paid to fly two citizens: Barnawi and Ali AlQarni, a fighter pilot in the Royal Saudi Air Force.
"I am very honored and happy to be representing all the dreams and all the hopes of all the people in Saudi Arabia and all the women back home," Barnawi told reporters last week.
The Crew Dragon capsule, which is fully autonomous, is expected to dock with the space station early Monday, with its passengers joining seven astronauts already aboard the orbiting laboratory.
The AX-2 crew will spend about eight days on the space station. During that time, they'll work through a lineup of more than 20 investigations and science projects - including stem cell and other biomedical research.
Whitson has flown on a Russian Soyuz spacecraft as well as NASA's space shuttle, but she said preparing for this mission was "obviously different" because it involved training to operate SpaceX's Crew Dragon, which has only been flying astronauts since 2020.
"That's been one of the biggest challenges for me is learning this particular spacecraft," she said. "But I've really enjoyed it."
Barnawi and AlQarni will be only the second and third Saudis to travel to space. The first was Prince Sultan bin Salman, who spent about a week on a NASA space shuttle mission in 1985.
Saudi Arabia has faced a barrage of criticism from the Biden administration and Congress over its human rights record, though the ties between the US and Saudi Arabia remain strong.
AlQarni said he believes Arabs' participation in spaceflight is a "great opportunity" that can inspire the region.
It will "hold a big message. ... We are holding hands, we are working together for the betterment of humanity and just trying to innovate," he said during a news briefing Tuesday.
It isn't the first time private citizens have paid their way to space. A company called Space Adventures brokered several such missions to the space station in the early 2000s, booking rides for wealthy thrill seekers on Russia's Soyuz spacecraft.
Axiom brought that business model to the United States, partnering with SpaceX to establish a framework for getting an array of customers to the space station. The company's first mission, AX-1, launched in April 2022 and marked the first time private citizens traveled to the space station from US soil.
Axiom's goal is to make these missions routine, offering more opportunities for people who are not professional astronauts to experience spaceflight. During a prelaunch news conference, Derek Hassmann, chief of mission integration and operations at Axiom Space, said his company expects to see more customers sponsored by governments similar to the AX-2 passengers from Saudi Arabia.
"Government astronauts are indeed a key piece of our business plan," he said. "Early in the program ... it wasn't clear to us what the balance would be between private individuals and government astronauts since nothing like this had ever been done before. But it's become clear to us that the government ... market is key, and we're pursuing that actively."
Axiom leadership envisions private spaceflight will continue even after the space station is retired, which NASA anticipates will happen in 2030. Axiom is one of several US companies gunning to create a new, privately owned space station. It's an effort supported by NASA, which aims to bolster private sector participation closer to home so the agency can focus on investing in deep-space exploration.
The AX-2 crew will work alongside the professional astronauts on the space station, though they will operate under different schedules. Once on board, they'll rely on existing crew to show them the ropes, including the kitchen and bathroom. And certain areas will remain off-limits, such as the air lock that astronauts use to conduct spacewalks, according to Hassmann.
CNN contributed to this report.
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