A watch party in Boston burst into cheers as Williams and Wilmore emerged from the capsule

NBC Boston reporter Jericho Tran was at the party for the return, where former classmates of Williams were among the crowd.

"Just massive relief," said one of the classmates. "We're just so proud of her."

"It's great to see she came back safe, and she's here," another said. "And everything's better."

Tran said she that spoke with Williams' mother just before the capsule splashed down and that she will head to Houston to see her daughter as she goes through medical rehabilitation.

If the two weeks NASA astronaut José Hernández spent in space are any guide, the astronauts who returned to Earth today may be in for a rough readjustment, he said.

“I was up there 14 days. I remember how miserable I was readjusting to 1G [normal gravity] as I sat there waiting to be extracted,” Hernández, who went to the space station in 2009, said during NBC News' live coverage of the landing.

Hernández returned to Earth on the space shuttle and touched down on solid ground. NASA has since retired its space shuttle fleet and now relies on SpaceX to shuttle its astronauts to and from low-Earth orbit. The company's Dragon capsules splash down in the ocean.

“I can only imagine these guys being up there nine months, and now they’re be-bopping in the ocean,” Hernández said. “They’re going to need a little bit of help.”

Some astronauts encounter difficulties with balance upon their return, he added, and it takes a few days to adjust.

Tennessee Tech issued a warm welcome home to Barry “Butch” Wilmore, who earned both his bachelor’s and master’s degrees from the institution.

“Over the last nine months, Barry has shown the world the strength and tenacity that our campus has witnessed up close over many years,” Tennessee Tech President Phil Oldham said in a statement. “His faith sustained him through unexpected challenges and brought him to this moment. He has made all of us at his alma mater enormously proud.”

After their medical exams, the four astronauts will board a helicopter flight to shore. From there, a NASA plane will fly them to the agency's Johnson Space Center, where they will reunite with their families.

NASA has ended its live broadcast of the landing, but a post-splashdown media briefing will be held at 7:30 p.m. ET.

Wilmore and Williams' trip to space lasted 286 days — far more than the 10-day journey planned.

But because of issues detected with their Boeing Starliner spacecraft during the test flight — particularly helium leaks and engine thruster problems — NASA was not comfortable bringing them back home on the vehicle. It has seen deadly accidents in the past, including the space shuttle Columbia disaster in 2003, when the shuttle broke up on re-entry, killing all onboard.

Although Boeing maintained that the Starliner was safe to fly the two astronauts back home, NASA was not convinced.

That's why Williams and Wilmore remained in space and joined Hague and Gorbunov on the SpaceX Dragon capsule today. However, the two had been trained to fly Boeing's vehicle, not SpaceX's. So they had to get trained up while they were on the International Space Station.

New spacesuits also had to be sent up because their Boeing spacesuits would not work in a SpaceX ship. All the while, Williams and Wilmore also took on the responsibilities of full space station crew members, helping with science experiments and ongoing maintenance of the orbiting lab. Williams even became its commander.

The wait is finally over. Williams was third to come through the hatch. Shortly after, Wilmore was helped out of the capsule.

The moment marked the long-awaited return of the two astronauts, who unexpectedly spent more than nine months on the International Space Station.

Russian cosmonaut Aleksandr Gorbunov was the second person to be helped out of the Dragon capsule. Gorbunov is returning from his first spaceflight, having logged 171 days in orbit.

First out of the capsule was NASA astronaut Nick Hague. He smiled widely at the camera and offered waves and a thumbs-up.

The public just got the first views of the Crew-9 astronauts inside the Dragon capsule. All four crew members smiled and waved to the camera as they waited to be helped out of the spacecraft.