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Clouds pass over the SpaceX Falcon 9, with the Crew Dragon spacecraft on top of the rocket, as it sits on Launch Pad 39-A on Wednesday at Kennedy Space Center in Cape Canaveral, Fla.
David J. Phillip/AP[/caption]
Updated at 4:20 p.m. ET
NASA and SpaceX were ready to launch a pair of astronauts from U.S. soil for the first time in nearly nine years on Wednesday, but the weather had other ideas.
The weather had been a concern all day after Tropical Storm Bertha — which made landfall in South Carolina — caused unsafe conditions at the pad and downrange, where the astronauts would have splashed down in case of a problem during launch. If the rocket ran into trouble during launch, the astronauts would be forced to land in the ocean, and inclement conditions could hamper rescue efforts or even prove dangerous for the crew.
The launch was scrubbed just 17 minutes before lift off. The next opportunities to try will be Saturday at 3:22 p.m. ET and Sunday May 31 at 3:00 p.m. ET.
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The Dragon spacecraft atop a Falcon 9 rocket at NASA's Kennedy Space Center. Astronauts Bob Behnken and Doug Hurley are set to launch on Wednesday afternoon.
SpaceX[/caption]
Earlier Wednesday, there had been optimism that the weather would clear and the launch would be a "go" as scheduled.
"We are go for launch!" NASA chief Jim Bridenstine tweeted shortly after noon Wednesday. He said NASA and SpaceX "will continue monitoring liftoff and downrange weather as we step into the countdown."
Speaking at a pre-launch briefing earlier in the week, Bridenstine called the historic launch "a big moment in time."
"It's been nine years since we've had this opportunity," he said.
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NASA astronauts Bob Behnken (left) and Doug Hurley are scheduled to lift off from Pad 39A at NASA's Kennedy Space Flight Center in Florida on Wednesday.
SpaceX[/caption]
At 4:33 p.m. ET, astronauts Bob Behnken and Doug Hurley were scheduled to lift off from Pad 39A at NASA's Kennedy Space Flight Center in Florida. They would be making the trip to space aboard SpaceX's Dragon crew capsule, the first time astronauts have ever traveled to the station aboard a private spaceship.
Hours before the planned launch, Hurley and Behnken suited up as they spoke for a few minutes with Bridenstine and SpaceX founder and CEO Elon Musk. The duo bid a brief goodbye to their families and proceeded to the pad in Tesla Model X electric cars. After riding the elevator to the top of the launch structure and walking across a connecting arm, the two were strapped into the Dragon capsule.
At about 45 minutes before the scheduled liftoff, launch control gave a "go" to load propellant in the Falcon 9 rocket.
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SpaceX CEO Elon Musk talks to reporters and NASA personnel at Kennedy Space Center in Cape Canaveral, Fla., on Wednesday.
John Raoux/AP[/caption]
"This is a dream come true, I think for me and for everyone at SpaceX," Musk said, adding: "I didn't even dream this would come true."
Asked whether he felt the weight of responsibility of having humans in SpaceX rockets for the first time, Musk said he did, especially when he spoke to the families of the astronauts. "I said, 'We've done everything we can to make sure your dads come back.' "
President Trump had been expected to attend the launch and deliver post-launch remarks inside NASA's massive Vehicle Assembly building, according to the space agency.
The Dragon capsule resembles the cone-shaped spacecraft of earlier generations, with some snazzy updates, such as a gleaming white exterior and, on the inside, touchscreen control panels. It will sit atop a SpaceX Falcon 9 rocket — the company's workhorse launch vehicle that has successfully flown 83 times since 2010.
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The Dragon capsule has powerful engines that allow it to escape from the top of the rocket if it gets into trouble.
SpaceX[/caption]
To some observers, the setup may look retrograde compared to the enormous space shuttle, which could fly back to Earth on wings. "We do think of winged vehicles landing like an airplane, as something that was more futuristic than a capsule on top of a rocket," says Lori Garver, a former NASA deputy administrator and CEO of Earthrise Alliance, an educational nonprofit.
But the capsule design has considerable safety advantages. Unlike the shuttle, it sits on top of the rocket, therefore avoiding debris that can fall off during launch — a problem that doomed the Space Shuttle Columbia in a 2003 launch. The position also makes it easy to eject the capsule if the rocket itself runs into trouble.
"These are safer systems," Garver says.
That's not to say that SpaceX hasn't had safety hurdles to overcome. In 2015, one of its uncrewed rockets exploded on the way to the space station. An accident review panel later concluded the failure was caused by a steel eyebolt that broke off inside the vehicle. In April 2019, a crew capsule exploded during a test of its launch abort rockets. An accident investigation concluded that a highly reactive oxidizer had leaked into a part of the rocket motors it was not supposed to be in.
Still, SpaceX has a good record overall. It has been flying cargo capsules to the space station since 2012, and the timeline for Wednesday's launch looks very similar to those earlier missions.
After launch, it will take around 12 minutes for the astronauts to get into orbit, and around 18 hours to reach the space station. The first stage of the Falcon 9, meanwhile, will reenter Earth's atmosphere and attempt to land on a floating drone ship.
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An uncrewed Dragon spacecraft is silhouetted against the Earth's horizon. The vehicle docked with the International Space Station and returned to Earth in 2019 as a dry run for the current mission.
NASA[/caption]
The Dragon spacecraft is designed to be fully automatic, but during the flight, Behnken and Hurley are expected to test manual flight systems to make sure the spacecraft behaves as expected.
The duo will remain in space for between one and four months before climbing back aboard the capsule and returning to Earth. The Dragon capsule will splash down in the Atlantic Ocean using four parachutes — the first time a water landing has been made by astronauts since the Apollo era.
For Garver, who was at NASA when the shuttle touched down for the last time, a successful launch will mark a new era for America in space. She says she thinks that NASA's programs have been hindered by politics and bureaucracy.
"The space program has been held back by trying to do things to keep jobs in certain [congressional] districts," Garver says. Turning part of the spaceflight mission over to private companies like SpaceX "is going to allow us hopefully to break out of that, and to have a better future."
Bridenstine says he hopes the launch will bring people together. "That's what these launches can do," he says. "It's not going to just unite Republicans and Democrats, it's going to unite the world."
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