Blue Origin, the rocket company headed by Amazon founder Jeff Bezos, is poised to launch the 10th test flight of its unmanned New Shepard rocket on Wednesday as it competes with Virgin Galactic to become the first to carry tourists on brief visits to space.
The liftoff is scheduled for 8:50am Central time (1450 GMT) from a Texas launchpad. The rocket will be carrying several science experiments for NASA.
The small rocket crossed the frontier of space last year, which is internationally agreed to be 62 miles (100 kilometres) above Earth, known as the Karman Line.
New Shepard reached a height of 66 miles (107 km) in April 2018.
The spacecraft is designed to one day carry up to six passengers for a journey lasting a total of 11 minutes.
Virgin Galactic, headed by British billionaire Richard Branson, is also working on a vessel of its own to carry tourists to space.
On December 13, 2018, Virgin Galactic's SpaceShipTwo, VSS Unity, flew higher than it ever had before, surpassing what the US Air Force considers the boundary of space, and marking the first manned flight to space from US soil since 2011.
The spaceship made it to a peak height of 51.4 miles (82.7 kilometers).
The US Air Force considers the space boundary to be at 50 miles.
The brief, suborbital flight - with two pilots on board - was a key milestone for the company which is striving to send tourists to space at a cost of $250,000 (roughly Rs. 1.8 crores) per seat.
Neither Blue Origin or Virgin Galactic is ready to board their first paying passengers, but both are targeting the first such flights this year.
Blue Origin has not yet announced the ticket price to ride on its New Shepard spaceflights.