Axiom-4 astronauts on SpaceX Crew Dragon welcomed aboard International Space Station (video)

A quartet of private astronauts have reached the space station.

Houston-based Axiom Space launched its fourth crewed mission to the International Space Station (ISS) early Wednesday (June 25), lifting off on a SpaceX Falcon 9 rocket from NASA's Kennedy Space Center (KCS), in Florida. The mission lifted off from KSC's Launch Complex-39A at 2:31 a.m. EDT (0631 GMT).

After a particularly long orbital chase — 28 hours between launch and rendezvous — the crew's Dragon spacecraft docked with the space station Thursday morning, at 6:31 a.m. (1031 GMT).

The Ax-4 astronauts rode a brand-new SpaceX crew Dragon to orbit. As such, naming rights for the spacecraft fell to the crew, who revealed their choice shortly after launch. Their pick: Grace.

Aboard Crew Dragon Grace is former NASA astronaut and Axiom's director of human spaceflight Peggy Whitson. Whitson holds the record for cumulative days spent in space by an American. That number began climbing again following her launch Wednesday, and is counting upward from 675. Her record will reach just shy of 700 days by the time the two-week Ax-4 mission returns to Earth.

Whitson is commander for Ax-4, and is joined by a trio of international, government-sponsored crew members: Shubhanshu Shukla, from India, serving as mission pilot, Polish mission specialist Sławosz Uznański of the European Space Agency, and Tibor Kapu of Hungary, also a mission specialist. The latter three are the first from their nations to journey on a mission to the ISS.

Crew Dragon Grace docked with the zenith (space-facing) port on the station's Harmony module. Hatches between spacecraft and ISS were opened at 8:14 a.m. EDT (1214 GMT), with the station's current crew awaiting the ingress of the Ax-4 astronauts for a short welcome ceremony.

"With your arrival right now, there are 11 astronauts from six countries, and all of us are here in order to advance human space exploration and scientific research, symbolizing international cooperation. So from this moment, you are also a part of Expedition 73," said Exp. 73 commander JAXA astronaut Takuya Onishi during opening remarks. "Welcome aboard," he added, before handing off the microphone to his new crewmates as they received their astronaut wings.

"We're looking forward to getting a lot of work done with you guys, and I really appreciate all the support you provided for to us in advance of actually even getting here," Whitson said in response.

"I'm very, very confident that the next 14 days are going to be amazing, advancing science and research and working together," said Shukla, mentioning that the view so far had surpassed his expectations.

"This is an ultimate scientific laboratory where we come to do science, to test the technologies of our countries, to do technology demonstrations and science outreach that I can't wait to do for the for the next two weeks, and we will all try to do our best representing our countries," Uznański said as he was handed the microphone.

Finally, as his wings were clipped to his jumpsuit, "I really feel that this is the best crew that you could join. It really feels great to be part of Expedition 73," said Kapu. "I'm 100% sure that this is going to be awesome."

The Ax-4 astronauts will spend about 14 days aboard the orbiting lab, completing a record number of science investigations and STEM (science, technology, engineering and math) outreach events. In total, they have over 60 experiments to undertake — more than any previous Axiom mission to date.

The crew's return date is largely dependent on weather at Dragon's splashdown zone in the Pacific Ocean. It will be SpaceX's second West Coast crew recovery, following a shift from Atlantic Ocean or Gulf recoveries due to the potential for spacecraft debris surviving atmospheric reentry and crashing back to Earth.