They returned in a SpaceX capsule and sailed back to the Florida coast for a 17-day tour. It cost them $55million each.
Although the trip was expected to last for a little more than a week due to weather problems, it lasted almost twice as long.
"Welcome back, planet Earth," radioed SpaceX Mission Control in Southern California. "We hope that you enjoyed the extra few hours in space."
Larry Connor, real estate tycoon, said that it was an "amazing mission".
The group thanked their hosts before leaving the space station on Sunday night. This included three NASA astronauts, whose mission is close to completion.
After decades of avoiding the Russian practice, NASA finally opened its space hatches for tourists. A Russian film crew and a Japanese fashion mogul flew in last fall. Each case involved an active-duty cosmonaut who traveled with them.
One of the latest guests was a former NASA astronaut who is now employed by Axiom Spa, the Houston company that managed the flight. This made it the first private trip to the station.
NASA wanted to be ready for the next crew after hosting them longer than they expected. SpaceX will launch three astronauts from NASA and one Italian to space station on Wednesday. They will replace the three Americans and one German astronaut who have been up there since November.
NASA standards are quite fast. The pace is incredible. Benji Reed, SpaceX's CEO, said that the company launched its first passenger -- a pair NASA test pilots -- two-years ago. The company just completed its first private flight into space using the same capsule.
Axiom managed the logistics of the trip for three customers, Connor from Dayton (Ohio), Mark Pathy, Canadian private equity CEO; and Eytan Stibbe, an Israeli investor. Michael Lopez-Alegria was their chaperone. He is an Axiom vice President and flew four times to space as a NASA astronaut.
After leaving the space station, Lopez-Alegria stated that it was an "amazing experience that we've had", which was even longer than expected.
Axiom joined forces with SpaceX to embark on the journey that began April 8 with a liftoff from NASA’s Kennedy Space Center. This was SpaceX’s second private flight and came just months after contest winners had taken an orbital trip with a billionaire.
The visitors were able to perform experiments in space and look back at Earth from their satellites.
Pathy stated, "It's been eye opening in so many aspects that I believe will have such an impact on my life."
Stibbe was particularly affected by the experience. Stibbe was a fighter pilot for Ilan Ramon, Israel’s first astronaut to die aboard the space shuttle Columbia in 2003.
Stibbe flew copies from Ramon's space diary as well as art and music made by Ramon's kids. He celebrated Passover by eating matzah bread and the gefilte fish provided by the station's Russians.
Axiom's second flight will take place next spring, as the company plans to have its own space station by 2030.
After the splashdown, Axiom operations director Derek Hassmann said that "there were a lot more eyes on this mission just in order to see if its practical." "Everybody understood that it was possible," but they wondered if amateurs could do this with reduced training without disrupting the crew of the space station.
Hassmann stated, "I believe we proved that we could do it."