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SpaceX's Polaris Dawn crew begins its fifth day in space, having achieved a series of record-setting milestones during a historic journey including the world's first commercial spacewalk.
Taking a spacewalk is nothing new.
NASA has been conducting these types of projects in space since 1965, when the Gemini program first introduced this capability to the United States.
Since then, astronauts from around the world have used spacewalk technology to explore the surface of the moon, maintain the Hubble Space Telescope, and help build the International Space Station. Today, a spacewalk, also called an extravehicular activity or EVA, is still routinely used at the space laboratory to allow astronauts to maintain its aging exterior.
But SpaceX demonstrated Thursday that conducting a spacewalk is a task that can be accomplished by the industrial sector, not just government astronauts, marking a major step toward commercializing that capability for Elon Musk's company.
It was the first time a private mission to space had attempted such an undertaking. And while the crew members were afraid to venture far outside the vehicle, they pushed boundaries and took significant risks.
Exposed to the emptiness of space
During the high-risk incident, the Crew Dragon capsule completely depressurized before the entire crew - including Shift4 Payments CEO Jared Isaacman, former U.S. Air Force pilot Scott "Kidd" Poteet, and SpaceX engineers Anna Menon and Sarah Gillis - was exposed to the vacuum of space.
Isaacman and Gillis then each left the vehicle for about 10 minutes, performing a series of tests to understand the functionality of their EVA suits, before retracting into the spacecraft and locking the circular hatch.
The dangers and stakes surrounding the spacewalk were enormous.
A wrong move during a crucial pre-breathing process leading up to the spacewalk could have put the crew at risk of decompression sickness, a condition commonly experienced by divers that causes nitrogen bubbles to form in the blood.
This crew also put the EVA suits - designed and developed by SpaceX in just 2 1/2 years - to the ultimate test. The suits had to protect them from the extreme temperatures of space, but also remain pressurized and provide oxygen to all four crew members.
But the spacewalk seemed to go off without any major problems. Isaacman reported after his first look outside the spacecraft, "We've all got a lot of work to do back home, but from here - it looks like a perfect world."
NASA Director Bill Nelson also congratulated the spacewalk in a post on X, formerly known as Twitter.
"Congrats @PolarisProgram and @SpaceX on the first commercial spacewalk in history!" Nelson wrote. "Today's success represents a huge step forward for the commercial space industry and @NASA's long-term goal of building a vibrant American space economy."
The four civilian astronauts will have plenty to celebrate upon their return. Even before the spacewalk, the mission had already distinguished itself from other private-sector-funded and -operated space voyages, which typically adhere to lower-risk mission profiles or involve short visits to the International Space Station led by professional astronauts.
The crew was also the first group of people to venture into the lower regions of the Van Allen radiation belt in fifty years.
Polaris Dawn reaches the radiation belts
According to NASA, the Van Allen belts trap concentrations of high-energy particles from the sun that interact with Earth's atmosphere, creating two dangerous bands of radiation.
After launching into orbit aboard a Falcon 9 rocket at 5:23 a.m. Eastern Time on Tuesday, the SpaceX Crew Dragon capsule immediately began raising its position, firing its onboard engines to launch the capsule into an oval orbit that extended as far as 870 miles (1,400 kilometers) from Earth.
That altitude is well into the innermost band of the Van Allen radiation belts, which begin about 1,000 kilometers above Earth.
The crew's high point-the farthest point of the journey from Earth-made Gillis and Menon the first women to travel so far from our planet.
The apogee also marked the farthest distance a human has flown since NASA's Apollo program ended in 1972. It was also the highest orbit ever achieved, breaking the record set in 1966 by NASA's Gemini 11 mission, which reached a distance of 855 miles (1,373 kilometers).
On the way home
After orbiting the planet at those altitudes for about six hours, with its crew safely inside, the Crew Dragon capsule restarted its engines to lower its orbit. Thursday's spacewalk took place as the vehicle circled about 115 to 455 miles (185 to 732 kilometers) above Earth.
The most risky part of the journey may be over, but the Polaris Dawn crew still has one major milestone ahead of them: coming home. The team is set to return to Earth, splashing down off the coast of Florida aboard the Crew Dragon capsule as early as this weekend.
Mission commander Isaacman, who also led and partially funded this space mission, previously told CNN that the Polaris Dawn crew would have only five or six days of life support in the vehicle.
That would mean the return to Earth could occur in the early morning of Sunday or Monday.
Splashdown could occur at seven possible locations off the east and west coasts of Florida, as with any Crew Dragon mission returning to Earth.
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