Virgin Galactic to Resume Test FlightsRichard Branson's commercial spaceflight company also plans to begin flying paying customers by the end of 2018.

Virgin Galactic plans to resume test flights more than two years after a fatalcrashdestroyed the company's sub-orbital craft known as SpaceShip Two.

Unpowered tests will begin this summer, Virgin CEO Richard Branson toldBloomberg周三。该公司还计划执行订单wered test flights every three weeks within Earth's atmosphere, he said. Starting this fall, some of those flights will extend into outer space.

Branson also revealed that he plans to make a trip into space himself next year, and that Virgin Galactic could begin flying paying customers into space by the end of 2018.

The company suffered a major setback in October 2014, when the original SpaceShip Two exploded shortly after it was released from the aircraft that carries it to a high altitude to perform tests. The crash killed the craft's co-pilot, but the pilot was able to eject safely.

Despite the crash, early customers' confidence in Virgin Galactic remains high, according to Branson.

"We will never be able to build enough spaceships," he told Bloomberg on Wednesday. "The demand is enormous."

Virgin Galactic publiclyunveiledSpaceShipTwo in February 2016, christening it "VSS Unity" at the suggestion of physicist Stephen Hawking. It's the first rocket manufactured by Virgin's Spaceship Company, and is designed to propel two pilots and up to six passengers into space at 3.5 times the speed of sound.

The new SpaceShipTwo last yearreceived permissionfrom the Federal Aviation Administration to fly commercially. Since then, it has performed multiple tests on the ground, including taxiing, monitoring the cabin's environmental controls, the electrical systems and the mechanism that mates SpaceShipTwo to her carrier aircraft.