If you fancy a near space ride, but don’t think the high Gs of a rocket launch would be for you, you’re in luck: Florida-based Space Perspective will soon be offering a much gentler journey. The NASA spinoff has designed a luxurious capsule to take passengers on a six-hour trip to the stratosphere, where they can enjoy panoramic views of our humble planet—which they’ll have risen above thanks to a giant hydrogen-filled balloon.
In this exciting era for space travel, a balloon trip above the Earth is one of the more interesting innovations. It wouldn’t be possible without clever engineering, a lot of simulation, cutting-edge digital twins and a desire to democratize the view of a lifetime.
Floating into the stratosphere
Imagine what it would be like to be a Space Perspective passenger. At a leisurely speed of 12 miles per hour (19 km/h), you and seven fellow travelers (plus one pilot) ascend into the stratosphere, the second lowest layer of Earth’s atmosphere. There, at an altitude of 100,000 feet (30 kilometers), you enjoy the breathtaking views of Earth, its curvature beneath your feet shrouded in the thin bluish veil of the planet’s gaseous coat. Above your head, the star-studded blackness of the cosmos extend into infinity.
Instead of being strapped into your reclining seat for the majority of the experience, you can roam freely around the Neptune space capsule, a luxurious lounge replete with decorative plants, interactive lighting and sound systems, and even a bar. Of course, your attention will most likely be fixed on the tall windows that ring the spherical capsule, which Space Perspective says will be the largest windows ever flown to space.
You won’t experience the sensation of microgravity floating, which is the main draw of rocket-powered sub-orbital flights. But then again, since you’re not in it for the adrenaline, you might happily settle for a glass of champagne instead, or just meditate while taking in the fragile beauty of our home planet.
“We are completely reimagining space travel,” Jane Poynter, Space Perspective co-founder and co-CEO said during a presentation at the Siemens Realize LIVE Americas 2023 user conference in June. “When most people think about space travel, they think about space suits and having the ‘right stuff.’ It’s for somebody else to do. We’ve totally rethought what it is for all of us to go to space.”
Engineering a new kind of space travel
Space Perspective isn’t the only company taking tourists into space, but for the average Joe, it may be the most appealing. While rocket-powered sub-orbital vehicles such as those operated by Virgin Galactic and Blue Origin may be vulnerable to teething problems, the balloon technology employed by Space Perspective is well-tested.
Since the 1950s, NASA and other research institutions around the world have been using similar balloons to lift research telescopes and other experiments up into the stratosphere. The core technology has been “safely flown to over 100,000 feet more than a thousand times,” Space Perspective co-founder and co-CEO Taber MacCallum told engineering.com.
Still, making the experience the smoothest it can be took some complex engineering. The capsule and the balloon have to withstand extreme temperature differences as they pass through the atmosphere. In the tropopause, the boundary between the troposphere and the stratosphere at an altitude of about 10 miles (16 kilometers), the craft will be subject to freezing temperatures as low as -120 F (-80 C). Once the spaceship rises above the tropopause, it encounters the near vacuum of the stratosphere.
At that point, 99% of the atmosphere’s mass would be below the spacecraft. In the thin residual gas of the stratosphere, the balloon, under which the capsule is suspended, expands so much that it would swallow the entire Statue of Liberty. But the polyethylene-based material that the balloon is made of must withstand such an expansion as it is required to take the capsule back to Earth.
“The SpaceBalloon is what is technically called a ‘zero-pressure balloon,’ meaning there is little to no pressure difference between the interior and the surrounding environment,” says MacCallum. “It cannot ‘pop.’ In the unlikely event there is a hole in the balloon envelope, it simply descends very slowly and floats down to a safe landing.”
In case anything goes wrong with the balloon, it will be backed up by a parachute system based on technology used by NASA to land rovers on Mars.
The Neptune capsule is made of a carbon composite material and features those large, panoramic windows, which added to the technical challenges of making the capsule. Engineers had to develop a special film that prevents heat-carrying infrared radiation from entering the capsule. At the same time, however, the windows have to be perfectly transparent to provide unspoiled views.
To tackle the challenges, Space Perspective used engineering software from Siemens, including STAR-CCM+ for computational fluid dynamics (CFD), and cloud computing resources from Amazon Web Services (AWS), which allowed engineers to run multiple simulations in parallel.
“There has been a huge amount of work done on how we control the temperature inside [the capsule],” said Poynter. “The Siemens software has been incredibly helpful to the team in really figuring out the air flows and energy flows in and around the capsule.”
Reinventing the sphere
The Space Perspective design team experimented with various shapes for the Neptune capsule. Ultimately, they determined that a conventional sphere would be the best and safest option.
“Some of our early designs were more squat and squashed,” said Poynter. “They were really fun to look at, but for physics reasons we ended up going with the circular globe. It makes the most sense in terms of mass efficiency, but it also provides a lot of head space.”
But there was one big problem with the sphere, and it only became apparent when simulating the end of the spaceship’s six-hour voyage. Spaceship Neptune will launch from the sea, from a vessel dubbed Marine Spaceport (MS) Voyager. The capsule will take two hours to rise to its peak altitude, where it will spend two hours lingering in the stratosphere, allowing its eight passengers ample time to enjoy the views. Finally, still attached to its balloon, the capsule will take another two hours to slowly descend and splashdown in the sea.
The simulations showed the splashdown to be the trickiest part of the journey. In early simulations, the spherical capsule bounced on the water surface “like a beachball,” according to Poynter.
The engineers came up with a solution: a cone-shaped extension attached to the bottom of the capsule, which slices up the water and prevents the bouncing. It took thousands of simulation rounds to perfect the shape of the patented “Splashcone,” Poynter said.
“Working with Siemens and Amazon Web Services has allowed us to quickly do thousands of design iterations on highly nuanced components such as the Splashcone that attenuates the splashdown,” added MacCallum. “These iterations would have historically taken weeks or even months—instead, they ran in a matter of hours.”
Neptune’s digital twin
To perfect every aspect of the flight experience, Space Perspective’s engineers built a digital twin of the entire system. The model takes into account detailed weather forecast data to accurately pinpoint where the capsule will land. During uncrewed flight tests conducted in 2021, the balloon landed within 2,600 feet (800 meters) of the predicted splashdown location. Data gathered during the tests were further fed into the models to prepare for crewed tests, which Space Perspective hopes to commence by early 2024.
“Before we produced a single piece of carbon, we ran many simulations of how the spacecraft would perform in flight,” said MacCallum. “That includes the structure in every pressure and thermal environment and at splashdown, the thermal environment and the interactions with the windows and external atmospheric pressures, and the Splashcone’s interactions with the water at splashdown and the rest of the capsule structure.”
Inside the capsule, conditions are similar to those in a commercial aircraft, said MacCallum. However, the capsule is fitted with a sophisticated life-support system inspired by technologies used at the International Space Station that scrub CO2 from the interior atmosphere, produce oxygen and control humidity.
“Each system is fully redundant,” said MacCallum. “There are two independent and fully redundant thermal control systems, for example.”
Although there will be a pilot aboard, the spaceship can fly fully autonomously or be controlled from Space Perspective’s mission control center in Florida.
If you’re tempted, tickets for Space Perspective’s balloon rides are already on sale for $125,000 apiece, a little over one fourth of the price of Virgin Galactic’s sub-orbital flights. The company is accepting deposits of $1,000 to $60,000. The bigger the deposit you pay, the sooner you’ll fly, said Poynter.
Space Perspective hopes to begin commercial operations in late 2024 and gradually build up a launch cadence of over 100 flights per year. The first flights will be taking off from Florida’s space coast, but Space Perspective plans to offer flights from its marine spaceport vessels from other locations around the U.S. and internationally.