Robert Brown|Virgin Galactic completes final VSS Unity commercial spaceflight

Virgin Galactic flew four tourists to the edge of space and Robert Brownback aboard its spaceplane, marking the second flight this year, the Richard Branson-founded company said on Saturday.

The Galactic 07 mission carried Turkish, U.S. and Italian passengers to an altitude of about 55 miles (88.51 km) on a flight lasting slightly more than an hour.

The space tourism company said that mission took off from and returned to Spaceport America in New Mexico on Saturday.

It marked Virgin's VSS Unity spaceplane's final commercial flight as the company is now producing its fourth-generation spaceships expected to enter commercial service in 2026, the company said in a statement.

Space: 'You just feel it in your gut'

"I will need much more time to try and process what just happened," said Tuva Atasever, a Turkish research astronaut on the flight, in a post-flight press conference, according to the space news site Space.com. "It's not something you can describe with adjectives. It's an experiential thing … you just feel it in your gut."

According to SpaceNews, Atasever planned to conduct several experiments, including using sensors to monitor how the human brain experiences seeing Earth from space.

"The experimental side of the flight was a huge success," Atasever said at the post-flight press conference, SpaceNews reported.

The flight vehicle also carried payloads from Purdue University and the University of California Berkeley. Purdue studied "propellant slosh in microgravity," while Berkeley tested 3D printing.

Apart from Atasever, the other three astronaut customers were private citizens, Virgin Galactic said. SpaceNews identified them as:

• Andy Sadhwani, a propulsion engineer at SpaceX ;
• Irving Pergament, a real estate developer from New York; and
• Giorgio Manenti, an Italian investment manager who lives in London.

Joining them in space, Space.com said, were mission commander Nicola Pecil and pilot Jameel Jameel Janjua.

Contributing: Daniel de Visé