SpaceShipTwo has made its first flight with its rocket, a significant milestone even if the engine didn't actually fire.

Wednesday's test by the team at Scaled Composites was a glide flight, the first with the rocket motor components, including tanks, installed. It was the 23rd flight of SpaceShipTwo, and Virgin Galactic has long said its first powered flight would come by the end of the year.

"It was also the first flight with thermal protection applied to the spaceship’s leading edges," Virgin said in a statement. "It followed an equally successful test flight last Friday which saw SpaceShipTwo fly in this configuration but remain mated to its WhiteKnightTwo carrier aircraft."

Time is ticking if Virgin and Scaled are to hit their goal for powered flight. In recent months, the team has been busy installing the oxidizer tank and rocket engine and making other preparations. The company says there will be at least two more glide flights before the first powered flight.

Virgin Galactic will offer sub-orbital rides for six passengers looking for a bit of weightlessness at the top of a ride that will take them into space at more than 350,000 feet. Virgin Galactic founder Sir Richard Branson visited the crew building and thte testing of the spaceships in Mojave last month and is looking forward to the first passenger flight.