After extensive testing and glide tests, Virgin Galactic's CEO George Whitesides said last year the company was "ready to go into powered flight." With engine testing complete, Virgin Galactic completed the seventh glide test of Unity at Mojave in January.

Virgin Galactic has not tested a powered flight — as opposed to a glide — of one of its spaceships since the fatal crash of Spaceship Enterprise on Oct. 31, 2014.

Richard Branson's space tourism venture is going to fire the engines of its vehicle during a flight at Mojave Air and Space Port, a person familiar with the situation told CNBC. (The news was first seen by the blog Parabolic Arc.)

Virgin Galactic is preparing for the first powered flight of its spacecraft Unity on Thursday, CNBC has learned.

The spacecraft Unity will be dropped during flight from the much larger, jet-powered mothership Eve. A crew of two will pilot Unity in Thursday's test. Unity is expected to fire its engines for as long as 30 seconds, aiming to reach speeds of 1½ times the speed of sound or more.

Unity is built and operated by The Spaceship Company, a subsidiary of Virgin Group. The company is also building two more spaceships, intended to become part of the fleet of Virgin crafts taking people to the edge of space.

The original SpaceShipTwo craft was built by experimental aircraft developer Scaled Composites. In 2016, Virgin Galactic unveiled its latest version of the SpaceShipTwo design, with alterations to avoid a repeat of the accident.

@VirginGalactic: Our team is prepping for a #SpaceShipTwo flight test today

Future passengers who are willing to fork out $250,000 will be taken up with help from the spacecraft's mothership. When it reaches a certain altitude, the Virgin Galactic craft will launch into space around 68 miles above the Earth's surface, before re-entering the planet's atmosphere.

Branson's space companies also recently got a boost from the Kingdom of Saudi Arabia, which announced intentions to invest $1 billion in Virgin Galactic, The Spaceship Company and Virgin Orbit. At the time of the announcement, Branson lauded Virgin Galactic was near its intended goal.

"We are now just months away from Virgin Galactic sending people into space and Virgin Orbit placing satellites around the Earth," Branson said.