While rocket-powered space tourism ventures like Virgin Galactic and Blue Origin have been grabbing headlines, a quieter space race has been unfolding to take tourists to the edge of space – not with rockets, but with balloons.
This year could be the year that stratospheric balloon tourism is poised to lift off as companies like HALO Space and Space Perspective prepare to take paying customers over 30 km (to the very top 1% of Earth’s atmosphere) in pressurized capsules to show off the majestic view of the Earth’s curvature and the blackness of space.
Sending tourists to the stratosphere in balloons presents several complex engineering challenges, even though the basic concept has existed for many years. The most fundamental challenge is protecting passengers from extreme temperatures at such high altitudes. The stratosphere’s atmospheric pressure drops to less than 1% of what we experience at sea level, and temperatures plunge below -40°C. Engineers must design a capsule to maintain comfortable pressure, oxygen levels, and temperature for the passengers inside.
The capsule also needs to provide spectacular views – the main reason for the journey. This creates an interesting engineering puzzle: incorporating large panoramic windows that can withstand the enormous pressure difference between the capsule’s interior and the thin external atmosphere while remaining completely safe and reliable.
Beyond these core technical challenges, developers must implement multiple layers of backup safety systems. These redundant systems need to protect passengers in worst-case scenarios, such as if the capsule develops a leak or experiences a catastrophic rupture. The stakes are exceptionally high since any failure at stratospheric altitudes could severely affect passenger safety.
Companies use aerospace-grade aluminium and synthetic fibreglass to build capsules that are light enough to be lofted by a balloon while robustly protecting occupants. Life support systems similar to submarines scrub CO2 and replenish oxygen.
A Brief History of Stratospheric Exploration
People have been attempting to reach the stratosphere by balloon for nearly 100 years. The first serious attempt was in 1931 with Swiss physicist Auguste Piccard. Piccard’s pressurized aluminium capsule, suspended beneath a hydrogen balloon, carried him and assistant Paul Kipfer to a record altitude of 15,781 m (51,775 ft). At that height, they became the first humans to witness the curvature of the Earth and the dark sky of space.
Piccard’s pioneering capsule design set the template for future stratospheric exploration. The spherical, airtight gondola provided a shirt-sleeved environment while protecting occupants from the stratosphere’s near-vacuum, frigid temperatures and intense solar radiation. A bottled oxygen supply and carbon dioxide scrubbers maintained breathable air. Piccard’s craft also featured innovations like variable ballast release to control ascent rate and a modifiable aperture in the balloon to manage gas expansion.
However, the flight was not without its moments. A faulty pressure regulator valve at altitude caused the cabin temperature to soar to 40°C. Piccard plugged the leak with a handkerchief doused in grease from a ham sandwich. The balloon’s gas release valve also froze, leaving the crew unable to control their ascent until the balloon reached a natural equilibrium. Piccard would refine the design in a second record-setting flight to 16,201 m the following year.
Over the next three decades, a handful of scientific expeditions sought to push higher into the stratosphere:
- In 1933, Soviet aeronaut Georgy Prokofiev reached 19,000 m (62,336 ft) in the USSR-1 balloon. Prokofiev’s pressure suit, needed in the event of cabin depressurization, was an early precursor to spacesuits.
- In 1935, American adventurers Albert Stevens and Orvil Anderson ascended to 22,066 m (72,395 ft) in the helium-filled Explorer II balloon, capturing the first photo showing the division between the troposphere and stratosphere.
- The United States Air Force and Navy launched operated balloon projects in the 1950s as a stepping stone to spaceflight. Project Manhigh (1957-1958) and Strato-Lab (1959-1961) evaluated human factors, pressure suit technology and cosmic radiation exposure at extreme altitudes.
The current crewed stratospheric altitude record was achieved on May 4, 1961, by Malcolm Ross and Victor Prather in Strato-Lab V. Lifting off from the deck of the USS Antietam in the Gulf of Mexico, their pressurized gondola ascended to 34.7 km (113,740 ft) – beyond the Armstrong limit where water boils at body temperature.
At the highest point, Ross and Prather spent 40 minutes conducting observations of the Earth’s limb (apparent edge) and photographing the violet hues of the daytime sky. Notably, they were “standing” in the open gondola on a platform rigged above the hatch, becoming the first people to view the stratosphere without intervening windows.
Tragically, on splashdown, the capsule unexpectedly tipped over in rough seas after a successful 10-foot parachute landing. Exhausted from the cramped 9-hour flight, Prather had unstrapped from the gondola to relax on an external platform when a wave struck. He slipped from his life vest and drowned, marking the only fatality of the stratospheric balloon era.
While the 1960s space race focused national attention and resources on rockets, balloons continued to be invaluable scientific tools. NASA’s Stratoscope I and II missions used pointing balloons to lift telescopes above 99% of the Earth’s distorting atmosphere for unprecedented views of the Sun and planets. The Soviet Union set uncrewed altitude records, including the Volga balloon, which reached 42.5 km in 1978.
In the 21st century, high-altitude ballooning is experiencing a renaissance for astronomy, atmospheric sampling, and commercial projects like Google’s abandoned Project Loon internet relay network.
Balloons provide long-duration, low-cost access to the stratospheric environment compared to rockets or aircraft.
What’s different now is the ambition to develop stratospheric balloons for passenger transport – fulfilling Auguste Piccard’s dream of “ballooning for all.”
While the engineering challenges are immense, from providing robust life support to giving passengers wide visibility without compromising structural integrity, companies like Space Perspective and HALO Space believe the technology has matured sufficiently to take paying customers safely to the edge of space. These modern capsule designs draw heritage from Piccard’s aluminium sphere, the Manhigh-Strato-Lab program and even the Biosphere 2 closed ecological system experiment.
Today, the two leading companies vying to launch commercial stratospheric balloon flights in the near term are:
- <b>HALO Space</b>: The Spanish company plans to charge $164,000 per seat for 6-hour flights to 30 km in its pressurized Aurora capsule. An uncrewed test flight was slated for September to validate key capsule systems. If successful, crewed test flights could commence in 2024.
- <b>Space Perspective</b>: Founded by the creators of the 1990s Biosphere 2 project, the company is developing a balloon-borne “Spaceship Neptune” capsule to take passengers to 30 km. A prototype was unveiled in February, though a test flight timeline has not been released.
Other players in the sector have faced headwinds. Zero 2 Infinity of Spain has shifted focus to using its stratospheric balloon systems as satellite launching platforms, while leadership departures and lawsuits have created turbulence for some in the sector.
As stratospheric balloon companies prepare to take on their first paying customers, they face challenges in demonstrating safety and overcoming a “boring” perception compared to the thrill of rocket flight. However, they also must overcome suspicions from those wealthy enough to pay that they are not as safe as rocket projects from larger companies.
This worry was further underscored by the 2023 Titan submersible disaster, which killed five and highlighted the risks of pushing the envelope with experimental tourist vehicles.
Regulators like the FAA in the USA demand extensive proof of passenger safety and reliability before allowing stratospheric tourist flights. Stratospheric balloons may have a broader appeal as a gentler experience suitable for a wider demographic compared to the rigours of rocket flight, but some question if there is enough “thrill factor.”
If regulatory approval is secured, the stratospheric balloon experience—which could be pitched as “space glamping”—could greatly expand the space tourism market. On a balloon, you could sip champagne while soaring in silence at 30 km, with the curvature of the Earth unfurling below the ink-black sky.
This future is one step closer if the results of HALO Space and Space Perspective’s demonstration flights are successful in the coming years. These tests should determine whether this is the breakout decade for stratospheric tourism.
- Stratospheric balloon tourism aims to take passengers over 30 km high in pressurized capsules for a view of near-space
- Engineering challenges include maintaining capsule pressure heat and providing oxygen at extreme altitudes
- The first stratosphere balloon flight was in 1931, and the current altitude record is 34.7 km, set in 1961
- HALO Space and Space Perspective are the leading companies, both planning flights to 30 km
- Challenges include stringent safety regulations and perception as less exciting than rockets
- If successful, stratospheric balloon trips could greatly expand the space tourism market in 2025 and beyond
