SpaceX is about to send four people on a wild — and risky — mission into the radiation belts. Here’s what to know

Upon his return, Isaacman imagined he likely would not go to space again.

“We kind of checked every one of the boxes we set out to achieve,” Isaacman told CNN, saying that Inspiration4 showed how people from various walks of life can train for and execute a mission to orbit. ”(I thought) that maybe I wouldn’t go back, that maybe the bar was set sufficiently high that this was a good time to stop.”

That assessment of his future in spaceflight, however, did not stick.

On Monday, Isaacman and three crewmates — including his close friend and former Air Force pilot, Scott “Kidd” Poteet, as well as two SpaceX engineers, Anna Menon and Sarah Gillis — will arrive at Kennedy Space Center in Florida to prepare for the launch of a far grander, more dangerous, and experimental trip to space.

While prior missions to space that were funded by wealthy businesspeople may have conjured images of self-indulgent joy rides, Polaris Dawn is a test mission designed to push boundaries.

Isaacman, Menon, Gillis and Poteet will spend five days aboard a SpaceX Crew Dragon capsule that will soar to altitudes higher than any human has traveled since NASA’s Apollo program ended in the 1970s. Their orbital path will extend high enough to plunge the vehicle and crew into a radiation belt, adding another element of peril to the already treacherous experience of spaceflight.

This crew of private citizens will also open the hatch of their spacecraft and expose themselves to the vacuum of space, marking the first time such a feat has been attempted by non-government astronauts. During this endeavor, the astronauts will be protected solely by brand-new Extra-Vehicular Activity (EVA) suits, which SpaceX designed and developed in just two and a half years.

With Polaris Dawn, Isaacman — the founder of payment services company Shift4, who is also a jet pilot with lifelong dreams of space travel — is making clear he is not just interested in duplicating what professional astronauts have experienced. He is seeking to advance space technology, helping to fund the development of new hardware as well as personally exposing himself to the risks of testing out that technology where it matters most: in the unforgiving void of outer space.

“What Jared is doing — he’s not just going for a joyride,” said Garrett Reisman, a former NASA astronaut who serves as a SpaceX consultant and helped lead the development of Crew Dragon. “Jared (wants) do things that SpaceX wasn’t necessarily doing on its own, to increase their capabilities, to get them to move the ball further downfield.”

An unprecedented mission

First announced in 2022, Polaris Dawn is the first of three testing and development missions under the Polaris Program that Isaacman said he will jointly execute and fund alongside SpaceX. He declined to say how much this mission cost.

The end goal of the Polaris Program is to take the first steps toward validating technology that SpaceX will one day need if it carries humans deeper into the cosmos — including spacesuits, EVA and life-support technologies.

After launch, the Polaris Dawn crew will travel into an oval-shaped orbit that extends as high as 870 miles (1,400 kilometers) from Earth. That’s well into the inner band of Earth’s Van Allen radiation belts, which begin at around 600 miles (1,000 kilometers) in altitude. The belts are areas where concentrations of high-energy particles that come from the sun and interact with Earth’s atmosphere are trapped, creating two dangerous bands of radiation, according to NASA.

Almost immediately after reaching space, the Polaris Dawn crew will begin a “pre-breathe” process to prepare for the spacewalk. It’s akin to what scuba divers do to avoid decompression sickness, otherwise known as “the bends.” The crewmates must purge nitrogen from their blood so that when the Dragon capsule is depressurized and exposed to the vacuum of space, the gas doesn’t form bubbles in their bloodstream — a potentially lethal condition.

“We don’t have an airlock on this mission,” Gillis told CNN, referring to the areas on board the International Space Station (ISS) that serve as special decompression chambers for astronauts heading out for a spacewalk. Polaris Dawn will instead take “a really novel and different approach” to the pre-breathing process that involves “slowly decreasing cabin pressure and raising oxygen concentration.”

Unlike any pre-breathe attempted on the International Space Station, the process will take roughly 45 hours — nearly two days, said Gillis, who works as a lead space operations engineer at SpaceX and trained the Inspiration4 crew for their mission.

Finally, to kick off their third day in space, the Polaris Dawn crew will open the Crew Dragon’s hatch as they’re about 435 miles (700 kilometers) above Earth. All four of the crew members and the entirety of the spacecraft’s interior will be exposed to the expansive void. Only Isaacman and Gillis will actually exit the spacecraft, however, tethered by a couple of umbilicals.

From beginning to end, the Polaris Dawn mission exposes the crew to more risk than other orbital space tourism missions have, including SpaceX missions that have carried paying customers to the International Space Station, which orbits about 250 miles (400 kilometers) above Earth.

Toxins and radiation

Over the two and a half years SpaceX and the Polaris Dawn crew have prepared for this mission, numerous technical challenges had to be addressed.

Even the EVA suits that SpaceX developed for this mission are high-stakes pieces of technology. For context, NASA has already tried for years to lock down a viable replacement for the aging puffy, white spacesuits used aboard the International Space Station.

However, Reisman notes, the SpaceX suits do not include a Primary Life Support System, or PLSS, which is essentially a backpack that allows ISS astronauts to float more freely through space to carry out complex tasks, such as repairing and replacing hardware outside the space station. Instead, the Polaris Dawn crew will receive their life support from long hoses attached to their spacecraft.

Then there’s the matter of the Crew Dragon vehicle itself. To make sure the spacecraft’s avionics — or electronics used for navigation and communication — could survive the heavy radiation environment encountered during the Polaris Dawn mission, engineers “literally strapped a lot of the avionics to a gurney and brought it to an oncology lab,” Isaacman said.

The SpaceX team hammered the avionics components with radiation until they broke, Isaacman said, to precisely determine when and how the technology might fail.

Once the Crew Dragon spacecraft is exposed to the vacuum of space, components inside the spacecraft could then vent off toxins — a natural trait of certain materials used to make various components — as the cabin is repressurized after the spacewalk, according to Menon.

To avoid that, the Crew Dragon and “a lot of the pieces of hardware that are flying in the vehicle went through basically a bake-out before we will ever go into space. What that does is it off-gasses a lot of those toxins,” said Menon, a lead space operations engineer at SpaceX who will also serve as the crew’s medical officer.

The “bake-out” involved putting the vehicle into a vacuum chamber at high temperatures, allowing the hardware to release the toxins before flight.

SpaceX also implemented automatic rebooting software, according to Menon, which can — without human intervention — troubleshoot computers that might malfunction due to radiation.

‘Significant risks’

Putting such a novel mission together in less than three years is incredibly fast by aerospace standards.

“Going faster is not necessarily more risky,” Reisman said, referring to rapid speed of development and extensive ground testing that SpaceX has carried out. “Taking large risks in testing when the consequences of failure are low results in reduced risk later when the consequences of failure are high.”

But “you should be nervous about (this mission),” he added. “Anytime you try something for the first time there are significant risks. I’ll feel much better when they are back inside with the hatch closed and latched” after the spacewalk.

SpaceX teams tried to mitigate risks and prepare for every potential challenge through a barrage of tests, some as simple as putting a handrail into a freezing chamber — set to negative 90 degrees Celsius — to see how cold to the touch a ladder might be when exposed to space, Isaacman said.

They even took the spacesuits to a testing site at White Sands Missile Range in New Mexico. There, the suits were struck by small pieces of debris traveling at orbital velocities to see how they could withstand micrometeorites and avoid punctures that would endanger the crew, according to Isaacman. (Objects in orbit around Earth travel at more than 17,000 miles per hour.)

Adding to the pressure to perform a perfect spacewalk is the fact that time will be extremely limited because the crew will have to lean heavily on oxygen supplies during the pre-breathe.

“We’ve got five, six days — maybe you can stretch it — of life support on the vehicle,” Isaacman said. “So you have to be really sure about where you have fault tolerance and redundancy in your systems. You’ve got to be really sure about the weather (for the splashdown return to Earth).”

Speaking to the challenges the crew will face, Isaacman added, “Sure, there is more risk in a development program than going to and from the International Space Station — but not a lot more risk … And some (risks) are just frankly unavoidable.”

Pushing the envelope

The Polaris Dawn crewmates told CNN they do not have any reservations about going on such an experimental mission. Gillis and Menon both said their experience through years of work at SpaceX — specifically on the Crew Dragon program — gives them close insight into how the company solves problems, which adds a layer of comfort.

And Poteet, who previously served 20 years in the Air Force and worked for Isaacman at fighter aircraft company Draken International, said that the Polaris Dawn mission shows what the SpaceX team can “accomplish in a very short few years (and) is a true testament to its professionalism.”

“I have absolutely zero reservations,” Poteet added. “I have full faith and confidence that they’ve crossed every ‘T’ and dotted every ‘I’ in preparation for our mission.”

Isaacman said his inspiration to pursue bold feats in space partly stems from SpaceX’s founding mission: To make humans a multiplanetary species, as CEO Elon Musk puts it, paving the way for a future in which people live and work on Mars or other foreign planets.

The summer before Inspiration4 took off, Isaacman visited SpaceX’s facilities in South Texas. That’s the site of testing and launch operations for the company’s Starship rocket — the largest launch vehicle ever created, which Musk bills as the vehicle that will land humans on Mars for the first time.

That visit was “like a religious experience,” Isaacman said. “We were surrounded by the people that were going to help humankind get to Mars and really explore our solar system. I don’t know — it made me a real believer.”

SpaceX is also undeniably a magnet for controversy, particularly surrounding Musk, who lately has landed in the news more for his political leanings and statements than for his space ambitions.

Isaacman credits Musk for having the vision that drives SpaceX on a day-to-day basis. But, he added, “SpaceX is a really, really big organization, and unfortunately, a lot of times, I feel like it all gets kind of boiled down to one person.”

“When I’m at SpaceX — and I spend a lot of time there — I don’t see vice presidents, I don’t see directors. I interact with a lot of (young employees),” Isaacman said. “I think SpaceX is on, for our time, the most incredible adventure imaginable … the possibility of unlocking life’s mysteries. Where do we really come from? What is our purpose? We might be really shocked about those answers, and, along the way, discover: Who knows what kind of technologies that could just change humanity’s existence — our trajectory in this world.”

-CNN