Update for 11:47 a.m.: The Virgin Galactic flight has landed. The names of the tourists have not yet been released; we will add more updates as they arrive.
Virgin Galactic plans to launch its third commercial spaceflight on Friday (Sept. 8), but you won't be able to watch the action live.
Liftoff will occur around the same as Virgin Galactic's previous missions, company officials told Space.com via email — so, about 10:30 a.m. EDT (1430 GMT). But Galactic 03 won't be livestreamed; we'll have to rely on updates that Virgin Galactic provides via social media.
In another departure from previous procedures, Virgin Galactic has not yet identified the three customers. Pretty much all we know is that they've been ticketholders for a long time.
"The three Galactic 03 crewmembers are the first of Virgin Galactic's group of 'Founder' astronauts — the first customers whose forward-thinking vision and early ticket purchases helped make the dream of regular commercial spaceflights a reality," Virgin Galactic wrote in a statement late last month.
"The Galactic 03 crew bought their tickets as early as 2005 and, since then, have been an active part of the company's vibrant Future Astronaut community," they added. (The ticket price back then was considerably cheaper than the current $450,000.)
The trio will fly aboard Virgin Galactic's SpaceShipTwo VSS Unity space plane with Colin Bennett, one of the company's astronaut instructors. Unity will be piloted by Nicola Pecile and Michael Masucci.
Unity lifts off beneath the wings of VMS Eve, Virgin Galactic's carrier aircraft. Eve drops the space plane at an altitude of about 50,000 feet (15,000 meters), at which point Unity fires its rocket motor to get up to suborbital space. Both Unity and Eve come back to Earth for runway landings.
Galactic 03 is Virgin Galactic's third commercial spaceflight, after Galactic 02 on Aug. 10 and Galactic 01 on June 29. When test flights are included, VSS Unity has reached the final frontier a total of seven times to date.