Bad weather thwarted the much-anticipated launch of SpaceX's first astronaut crew Wednesday, a flight that would have marked the return of human spaceflight from U.S. soil for the first time in nearly a decade.
Astronauts Bob Behnken and Doug Hurley had been scheduled to lift off aboard SpaceX's Crew Dragon capsule from Kennedy Space Center in Florida to the International Space Station at 4:33 p.m. ET, but cloudy conditions forced launch operators to stand down with less than 20 minutes to go in the countdown.
The Air Force's 45th Space Wing, which oversees space launch operations from the East Coast, had been closely monitoring weather reports at the launch site after Tropical Storm Bertha formed early Wednesday off South Carolina. SpaceX and NASA will now attempt the test flight at 3:22 p.m. ET Saturday.
The historic launch will be the first time that NASA astronauts have flown to the orbiting lab in a commercially built spacecraft. It will also be the first time that human passengers are launched into orbit from the U.S. since NASA retired its space shuttle fleet in 2011.
"Our country has been through a lot," NASA Administrator Jim Bridenstine said Tuesday at a news briefing. "But this is a unique moment when all of America can take a moment and look at our country do something stunning again, and that is to launch American astronauts on an American rocket from American soil to the space station."
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Shortly before 3 p.m. ET, President Donald Trump and first lady Melania Trump arrived at Kennedy Space Center, flying past the launchpad aboard Air Force One. According to NASA, the last time a sitting president flew to Florida to witness a crewed launch in person was in October 1998, when Bill Clinton watched the space shuttle Discovery blast off.
If the Crew Dragon capsule lifts off on Saturday, Behnken and Hurley will spend around 19 hours orbiting the Earth before their capsule makes its rendezvous with the space station.
The test flight is the last milestone for SpaceX under NASA's Commercial Crew Program, which was designed to foster partnerships with private companies to develop spacecraft for routine trips to the space station.
After NASA shuttered its space shuttle program, the agency was forced to buy rides to the space station aboard Russian capsules and rockets. If SpaceX's launch is successful, American astronauts may soon have a new way to travel to and from the orbiting outpost.
SpaceX has spent the past six years building and testing its Crew Dragon capsule. For years, the company has used an uncrewed version of the spacecraft to ferry supplies to the space station, but this will be SpaceX's first launch with humans onboard.
The company received more than $3 billion from NASA to develop the capsule under the Commercial Crew Program. NASA also awarded more than $4.5 billion to Boeing to design a rival capsule known as the CST-100 Starliner. The idea is to allow NASA to contract out standard flights to the space station while the agency focuses on other science and exploration goals.
If it is successful, the test flight could bolster the nascent private spaceflight industry and help pave the way for other commercial ventures, including missions to the moon or Mars.
"The goal is for NASA to be a customer," Bridenstine said this month in a news briefing. "We want a very robust commercial marketplace in low-Earth orbit."