However you measure it, though, the flight represents a triumph for Virgin Galactic - and a stark change from just over four years ago, when the company grabbed headlines for a very different, altogether tragic reason.
The goal is for the vehicle to reach an altitude of at least 50 miles (80 kilometres).
The test flight is scheduled to depart from Mojave, California at 1000 Eastern Time (1600 CET) on Thursday.
One of the pilots handed Sir Richard a small Earth stress ball when the two hugged after the space ship landed safely following about an hour's journey.
Richard Branson center celebrates with pilots Rick "CJ" Sturckow (L), and Mark "Forger" Stucky (R), after Virgin Galactic's tourism spaceship climbed more than 50 miles high above California's Mojave Desert on December 13, 2018.
This May 29, 2018 photo provided by Virgin Galactic shows the VSS Unity craft during a supersonic flight test.
But in October, Branson told CNBC that he could be in space "in months and not years". "When you are in the test flight program of a space company, you can never be completely, 100 percent sure, because that's what a test flight program is", he said.
Image The VSS Unity took off the Mojave Desert early on Thursday
In previous test flights, SpaceShipTwo flew to a peak altitude of 32 miles (52 km).
Virgin Galactic has not yet said when it plans on beginning its first passenger flights.
Branson isn't alone in the space tourism business: Jeff Bezos' Blue Origin is planning to take space tourists on suborbital trips, using the more traditional method of a capsule atop a rocket that blasts off from a launch pad. The planned sub-orbital lobs have been delayed repeatedly since the passenger-toting rocketplane's lavish unveiling back in 2009 and the firm has had to overcome a number of setbacks, including an incident that led to the inflight destruction of its predecessor in 2014 and the death of one of the two pilots onboard.
Virgin Galactic, which is charging $250,000 for a 90-minute flight, has said more than 600 people have bought tickets or put down deposits for an eventual voyage.
"The anticipated addition of SpaceShipTwo to a growing list of commercial vehicles supporting suborbital research is exciting", Ryan Dibley, Flight Opportunities campaign manager at NASA's Armstrong Flight Research Center in Edwards, California, said in a statement.
The endeavour began in 2004 when Branson announced the founding of Virgin Galactic in the heady days after the flights of SpaceShipOne, the first privately financed manned spacecraft that made three flights into space.