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The crew of SpaceX's Polaris Dawn spacecraft begins its fifth day in orbit, marking several record-breaking milestones on the historic journey, including the world's first commercial spacewalk.
Spacewalking is nothing new.
NASA has been conducting space exploration since 1965, when the Gemini program first gave the United States the opportunity to realize these capabilities.
Since then, astronauts from around the world have used spacewalk technology to explore the lunar surface, service Hubble Space Telescope and help build the International Space Station. Today, spacewalks, also called extravehicular activities or EVAs, are still regularly used on the orbiting lab to allow astronauts to service and maintain its aging exterior.
But SpaceX demonstrated Thursday that spacewalking is a task that can be accomplished by industry, not just government astronauts. In doing so, Elon Musk’s company took a major step toward commercializing the capability.
It was the first time a private space mission had attempted such an undertaking, and while the crew members didn't venture far outside the ship, they did push the boundaries and take significant risks.
Exposed to the void of space
During the extremely dangerous event, 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 Gillies, were exposed to the vacuum of space.
Isaacman and Gillis then exited the spacecraft for about 10 minutes each to conduct a series of tests to evaluate the functionality of their spacewalk suits, before returning inside the spacecraft and locking the round hatch.
The dangers and stakes involved in spacewalking were enormous.
A wrong move during the important “pre-breathing” process before a spacewalk could have put the crew at risk of “the bends” or decompression sickness, a condition experienced by scuba divers in which nitrogen bubbles form in the blood.
The crew also put their EVA suits, designed and developed by SpaceX in just 2.5 years, through a rigorous test. The suits had to protect them from the extreme temperatures of outer space, as well as remain pressurized and supply oxygen to all four crew members.
But the spacewalk appears to have gone without any major problems. Isaacman reported after taking his first look at the spacecraft from the outside: “We all have a lot of work to do back home, but from here, it looks like a perfect world.”
NASA Administrator Bill Nelson also congratulated the astronauts after their spacewalk. post on Xformerly known as Twitter.
“Congratulations to @PolarisProgram and @SpaceX on the first-ever commercial spacewalk!” Nelson wrote. “Today’s success represents a giant leap forward for the commercial space industry and @NASA’s long-term goal of building a vibrant U.S. space economy.”
The four civilian astronauts will have plenty to celebrate upon their return. Even before the spacewalk, the mission already stood out from other privately funded and operated flights to orbit, which tend to follow less-risky mission profiles or include brief visits to the International Space Station led by professional astronauts.
The crew also became the first group of people to travel to the lower Van Allen radiation belt in five decades.
Polaris Dawn reaches radiation belts
The Van Allen belts trap concentrations of high-energy particles that come from the sun and interact with Earth's atmosphere, creating two dangerous bands of radiation, according to data NASA.
After the crew launched Launched into orbit by a Falcon 9 rocket at 5:23 a.m. ET Tuesday, SpaceX's Crew Dragon capsule immediately began lifting off, using onboard engines to enter an oval orbit that extended out to 870 miles (1,400 kilometers) from Earth.
This altitude is in the inner band of the Van Allen radiation belts, which begin about 600 miles (1,000 kilometers) above Earth.
The crew's apogee—or farthest point from Earth—made Gillis and Menon the first women to travel that far from our planet.
The apogee also marked the farthest human journey since the end of NASA's Apollo program in 1972, and it was the highest orbit around the Earth ever achieved, breaking the record set in 1966 by NASA's Gemini 11 mission, which reached 853 miles (1373 kilometers).
Returning home
After completing about six orbits of the planet at those altitudes with the crew safely inside, the Crew Dragon capsule fired its engines again to lower its orbit. Thursday's spacewalk took place while the ship was in orbit between 115 and 455 miles (185 and 732 kilometers) above Earth.
The riskiest part of the journey may be behind us, but the Polaris Dawn crew has one more important step ahead of them: the return home. The team is set to return to Earth by splashing down off the coast of Florida aboard the Crew Dragon capsule this weekend.
Mission commander Isaacman, who also led and partly funded the orbital mission, previously told CNN that the Polaris Dawn crew would have life support systems on board for only five to six days.
This means that the return to Earth could happen early Sunday or Monday morning.
The splashdown could occur at any of seven potential locations off the east and west coasts of Florida, as is the case for every Crew Dragon mission returning to Earth.
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