A new space race has begun with both Sir Richard Branson and Elon Musk hoping to launch passengers into space in 2018.
In a weekend interview with the Telegraph, Branson said he won't give a date but would be disappointed if launch hadn't happened before the end of 2018.
"The test programme is going really well, and as long as we've got our brave test pilots pushing it to the limit we think that after whatever it is, 12 years of hard work, we're nearly there," he told the Telegraph.
Branson said he would be disappointed if he hadn't travelled into space by the end of this year on a test flight.
Elon Musk, meanwhile, already has two investors signed up to do a round trip of the moon in the fourth quarter of 2018.
The pair, who have remained anonymous since the announcement, will travel in an autonomous, unpiloted spacecraft in a lunar fly-by.
"I think they are entering this with their eyes open, knowing that there is some risk here," Musk told reporters in a telephone news conference in February.
"They're certainly not naive, and we'll do everything we can to minimise that risk, but it's not zero. But they're coming into this with their eyes open," said Musk, adding that the pair will receive "extensive" training before the flight.
While Musk's passengers remain a mystery, the renowned physicist Stephen Hawking will be among Virgin Galactic's first passengers.
Hawking said Branson offered him a seat which he accepted immediately.
It's estimated the cost of a trip on the SpaceX Dragon 2 to the moon would be roughly $100 million. A trip into sub-orbital space on the Virgin Galactic SpaceShipTwo comes in at a more reasonable $350,000.
The trip would also require nerves of steel after recent disasters.
A SpaceX rocket exploded during a test flight last September, though Musk believes passengers would have been able to escape.
Virgin Galactic was struck by tragedy in 2014 when a co-pilot was killed and another pilot seriously injured in a crash in the Mojave desert.