Three NASA astronauts and their Russian cosmonaut crewmate flew to the Kennedy Space Center on Sunday to prepare for launch atop a SpaceX Falcon 9 rocket early Friday, kicking off a planned six-month tour of duty aboard the International Space Station.

Flying in from the Johnson Space Center in Houston, Crew 8 commander Matthew Dominick, co-pilot Michael Barratt, Jeanette Epps and cosmonaut Alexander Grebenkin landed at the Florida spaceport’s 3-mile-long runway at 1:45 p.m. EST. Barratt is a veteran of two previous space flights while his three crewmates are rookies.

“Wow, it’s great to be at the Cape!” Dominick said from the runway. “I’m a kid in the candy store. … It’s an incredible time to be involved in spaceflight.”

As if to prove his point, SpaceX launched a Falcon 9 rocket carrying 24 Starlink internet satellites from the nearby Cape Canaveral Space Force Station three hours after the station crew arrived in Florida, giving them a spectacular taste of things to come.

A few hours later, NASA and SpaceX managers concluded a flight readiness review and tentatively cleared the crew for launch.

“It’s hard to believe that it’s been 25 years since we launched the first hardware for the International Space Station and that we’ve had crews up there for more than 23 years,” said Ken Bowersox, a former shuttle commander and now chief of NASA’s human spaceflight program. “Throughout that time, safely launching and returning our crew members has been a critical priority.

“Today’s review was very thorough. We talked about some of the technical items on the Falcon 9 rocket and the Dragon spacecraft. We talked about the readiness of the crew and space station. At the end of the review, everybody pulled ‘go.'”

Dominick and company plan to strap in aboard their SpaceX Crew Dragon — “Endeavour” — overnight Monday for a dress rehearsal countdown. A few hours later, SpaceX plans to test fire the Falcon 9’s first stage engines to clear the way for the reusable booster’s first flight.

Assuming the tests go well and the weather cooperates, the crew will strap in for real Thursday night and blast off from historic pad 39A at 12:04 a.m. Friday. That’s the moment Earth’s rotation will carry the pad into the plane of the space station’s orbit to enable a rendezvous.

Once in space, Dominick and Barratt will monitor a series of autonomously executed thruster firings to catch up with the space station early Saturday, moving in from behind and below. After looping up to a point directly in front of the outpost, Endeavour will press in for docking at the lab’s forward port at 7 a.m.

Standing by to welcome them aboard will be Soyuz crewmates Oleg Kononenko and Nikolai Chub and NASA astronaut Loral O’Hara, who were launched to the station last September.

Also on board the space station: Crew 7 commander Jasmin Moghbeli, European Space Agency astronaut Andreas Mogensen, Japanese flier Satoshi Furukawa and cosmonaut Konstantin Borisov, launched from the Kennedy Space Center last Aug. 25.

After a week-long handover period to help familiarize the Crew 8 fliers with the ins and outs of station operations, Moghbeli, Mogensen, Furukawa and Borisov will undock March 8 and return to Earth, splashing down off the coast of Florida to wrap up a 196-day mission.

“I truly can’t believe this adventure is almost over,” Moghbeli, a veteran Marine helicopter pilot, posted on social media. “This is what I’ve dreamed of since I was a little girl. I was afraid I might get here and be disappointed after having such high expectations my entire life but, if anything, this experience has surpassed all my expectations.”

The Crew 8 launch and docking is the first in a multi-step procedure by NASA and the Russian federal space agency Roscosmos to replace the space station’s seven long-duration crew members with a fresh set of operators. Crew rotations are generally carried out twice each year.

With Crew 8 on board the ISS and Crew 7 back on Earth, Roscosmos plans to launch veteran cosmonaut Oleg Novitskiy, Belarus guest flier Marina Vasilevskaya and NASA veteran Tracy Dyson on March 21 aboard the Soyuz MS-25/71S ferry ship.

The mission is known informally as a “taxi flight,” in which a short-duration crew delivers a fresh Soyuz to the station and then flies home aboard a Soyuz that is nearing the end of a six-month stay. But this time around, the taxi flight is needed to accommodate a yearlong stay in space by Kononenko and Chub.

Novitskiy and Vasilevskaya will return to Earth on April 2, along with NASA’s O’Hara, using the Soyuz MS-24/70S spacecraft that carried Kononenko, Chub and O’Hara to the station last September.

Kononenko and Chub will return to Earth with Dyson in September aboard the Soyuz MS-25/71S spacecraft delivered by Novitskiy.