Balloon companies are developing technology to take tourists on rides up to 100,000 feet in the sky.

Over the past few years, companies such as SpaceX, Blue Origin, and Virgin Galactic have been transporting paying customers into space, making commercial space flight increasingly common.

Startups such as Zephalto from France, Space Perspective from Florida, and World View from Arizona are working on providing tourists with an unusual vantage point of the Earth by launching them into the stratosphere using pressurized capsules and massive gas-filled balloons.

"According to Ryan Hartman, CEO of World View, the capsule is designed to carry eight customers and two crew into the stratosphere. It will feature a center bar where people can gather, as well as a bathroom on board."

The balloon rides will last approximately 6 hours and will not transport passengers to space. The majority of rides will reach altitudes of 15 to 19 miles above the earth's surface, flying in the stratosphere. According to the U.S. government, the start of space is typically defined as being 80 kilometers, or about 50 miles, above the earth's surface.

Jane Poynter, Space Perspective's founder and co-CEO, holds a different perspective.

"Poynter stated that there is no standard definition of space. As a spaceship, we are regulated and if we exceed 98,000 feet, we are considered a spaceship. Beyond the capsule, it's essentially a vacuum. We are above 99% of Earth's atmosphere, which explains the deep black color of the sky."

On a stratospheric balloon ride, passengers will experience a sensation similar to being on an airplane, but without weightlessness.

"Zephalto's founder and chief pilot, Vincent Farret d'Astiès, stated that physical requirements are not necessary to board the balloon. As long as you can board a standard plane, you can board the balloon."

All three companies, World Views, Space Perspective, and Zephalto, expressed satisfaction with consumer interest in their respective space tourism offerings. World Views sold 1,250 tickets, Space Perspective sold 1,800, and Zephalto's initial flights were fully booked, although the company did not disclose the number of tickets sold.

The cost of tickets for space tourism companies such as World View, Zephalto, and Space Perspective varies, with prices ranging from $50,000 to $184,000 per seat. However, the availability of commercial service is still uncertain.

Although Zephalto has not yet conducted crewed tests at the company's target altitude of approximately 15 miles above the earth's surface, it is the only spacecraft to have undergone crewed tests so far.

To learn more about this emerging market, check out the video.