Washington DC - The crew of the first entirely private mission to dock with the International Space Station (ISS) arrived on Saturday after a flight of more than 20 hours, live images from the US space agency NASA showed.

The space travelers had an unplanned wait of about 45 minutes at a distance of 65 feet from the ISS because of a problem with a video camera needed for the docking maneuver.

The Ax-1 mission blasted off on Friday from Cape Canaveral in Florida in a Crew Dragon space capsule, boosted by a Falcon 9 rocket.

It carried the first wholly private crew, made up of Spanish-American astronaut Michael López-Alegría, US entrepreneur Larry Connor, Israeli entrepreneur and pilot Eytan Stibbe, and Canadian investor Mark Pathy.

The co-pilots each paid about $55 million for the flight, according to media reports.

The mission is run by private spaceflight company Axiom, NASA, and Tesla billionaire Elon Musk's SpaceX.

The four members on board are due to stay at the ISS for about a week and carry out scientific experiments. They were met by astronauts currently stationed there, including US astronauts Thomas Marshburn, Raja Chari, and Kayla Barron, German astronaut Matthias Maurer, and three cosmonauts – Oleg Artemyev, Denis Matveev, and Sergey Korsakov.

NASA chief Bill Nelson welcomed the launch as the beginning of a "new era" paying tribute to what he described as a "historic launch."

"This journey is the culmination of long hours of training, planning, and dedication from the crew and the entire Axiom Space team, our partners at SpaceX, and of course, a credit to NASA’s vision to develop a sustainable presence in low-Earth orbit," said Axiom Space chief Michael Suffredini.

Axiom Space was founded by former NASA executive Suffredini and Iranian-American entrepreneur Kam Ghaffarian in 2016.

The company is positioning itself as a major player in the space travel market in the future, planning its own commercial space station. NASA has already contracted the company to build a commercial ISS module.

Axiom Space commander López-Alegría distanced himself from the term "space tourists" before the mission, saying it was not a vacation for the crew.