New York (CNN Business) Blue Origin, the stealthy company founded by Amazon's billionaire founder Jeff Bezos, just launched another test flight of its tourism rocket as it steadily inches toward sending paying customers into space.

The rocket took off from a test site in rural Texas on Wednesday and soared more than 60 miles into the upper atmosphere, across the boundary that is widely considered the edge of space.

It marked the 12th uncrewed test flight for Blue Origin's fully autonomous rocket and spacecraft system, called New Shepard. And it could be one of the last before the company is ready to start flying paying customers, though it's not clear exactly when the company will reach that milestone.

Earlier this year, Ariane Cornell, Blue Origin's director of sales, said the company was looking to fly passengers in 2019. But those plans changed. During the webcast of Wednesday's launch, she said only that the company is getting "very close."

The New Shepard capsule, which will house passengers and is equipped with large windows for panoramic views, detaches from the rocket near the top of its flight path. During Wednesday's test flight, it climbed about 343,000 feet, or 65 miles. Future passengers will be able to experience a few minutes of weightlessness before the descent.

Three parachutes are used to slow the capsule as it falls back to Earth, and it was traveling about 16 miles per hour before hitting the ground on Wednesday and kicking up a puff of sand. The trip lasted just over 10 minutes from takeoff to landing.

After the rocket detached from the capsule, it reignited its engine to execute a pinpoint landing back on the launch site. Blue Origin says New Shepard can land and fly again with "minimal refurbishment," which is key to bringing down the cost per launch. It was the sixth flight for the rocket and capsule that flew on Wednesday. Its most recent trip before that was in May.

This launch was also the ninth test fight that involved research payloads. One project, called OSCAR, will test a "mixture of gasses" that could help NASA understand how to convert common waste to "propulsion or life support" on deep-space exploration missions, according to a press release.

Also on board New Shepard were thousands of postcards from kids around the world who are part of Blue Origin's Club for the Future, a nonprofit designed to inspire the next generation of scientists and engineers.

Space tourism as a business

Virgin Galactic SPCE Blue Origin's New Shepard is slated to compete directly with, the space tourism company founded by British entrepreneur Richard Branson, by flying wealthy passengers on scenic trips to suborbital space.

Both companies have been developing their hardware since the early 2000s. And they were expected to finally begin commercial operations this year.

Galactic SPCEU , which recently made its stock market debut, is now planning to launch the first paying customers on its supersonic space plane by mid-2020. It already has more than 600 customers lined up, most of whom agreed to pay between $200,000 and $250,000 per seat.

Blue Origin has not publicly confirmed how much its tickets cost. The company has tended to keep its cards much closer to the chest by only confirming test flights after their plans are made public in regulatory records.

The company is funded solely by Jeff Bezos, whose $100 billion-plus fortune makes him one of the richest people in the world.

Some in the space industry are bullish on space tourism, suggesting it can become a major revenue maker. But critics question whether there's enough demand among the world's ultra-rich to make it a sustainable business.