Virgin Galactic has completed what is expected to be its final test flight before taking paying customers on brief trips to space, marking what the space tourism company describes as a “fantastic achievement”.

Six of the company’s employees, including two pilots, landed at Spaceport America in southern New Mexico in the US after the short up-and-down flight that included a few minutes of weightlessness.

It took about an hour for the mothership to carry the spaceplane to an altitude of 13,560 metres where it was released and fired its rocket motor to make the final push.

“Successful boost, WE HAVE REACHED SPACE!” Virgin Galactic tweeted.

It reached an altitude of 87 kilometres before gliding back down to the runway, according to the company.

Jamila Gilbert, who grew up in southern New Mexico and leads the company’s internal communications, was among those on board who were evaluating what it will be like for paying customers.

“It is hard to put into words what this experience was like but I’m sure I’ll spend the rest of my life trying,” Ms Gilbert said in a statement released after the flight.

“As one of the very few non-technical people to fly to space, my role in this mission marks a sea change in who can go to space, and is a promising sign of the opportunities Virgin Galactic and the commercial space sector are ushering in.”

The flight came nearly two years after founder Richard Branson beat fellow billionaire and Amazon founder Jeff Bezos and rocket company Blue Origin into space.

Mr Bezos ended up flying nine days later from West Texas and Blue Origin has since launched several passenger trips.

US aviation authorities banned Virgin Galactic launches after Branson’s flight to investigate a mishap.

Virgin Galactic has been working for more than a decade to send paying passengers on short space hops and in 2021 finally won the federal government’s approval.

The next step will be for Virgin Galactic to analyse data from Thursday’s flight and inspect the planes and other equipment as the company prepares for commercial service, possibly as soon as late June.

The initial commercial flight will include members of the Italian Air Force who will conduct experiments.

Next will come customers who purchased tickets years ago for their chance at weightlessness aboard a winged spacecraft that launches from the belly of an airplane.

About 800 tickets have been sold over the past decade, with the initial batch going for $US200,000 ($307,200) each.

Tickets now cost $US450,000 per person.

Virgin Galactic has reached space five times since 2018 and will be aiming for 400 flights per year from Spaceport America once it finishes building its next class of rocket-powered planes at a facility in neighbouring Arizona.