Virgin Galactic said the fourth flight of its SpaceShipTwo passenger rocket ship would “aim to fly higher and faster”.
Its intention is to reach a height of more than 80km, the altitude at which space stated to begin.
Sir Richard is in a race with Elon Musk and Jeff Bezos to send the first fee-paying passengers into space.
He founded the commercial spaceflight company in 2004, shortly after Mr Musk started SpaceX and Jeff Bezos established Blue Origin.
In 2008, Virgin Galactic first promised sub-orbital spaceflight trips for tourists would be taking place “within 18 months”. It has since regularly ended with similar promises to have space flights airborne in the near future.
But delays and a fatal crash in 2014 prevented Sir Richard’s original ambitions.
The new flight of the plane, also known as the VSS Unity, will take place over the Mojave desert in southern California.
The company stated it planned to “burn the rocket motor for durations which will see our pilots and spaceship reach a space altitude for the first time”.
Though, it notified: “Although this could happen as soon as the next flight, the nature of flight test means that it may take us a little longer to get to that milestone.”