Polaris Dawn, the private SpaceX mission currently orbiting Earth, has already set several records since its launch on September 10. Hours after liftoff, the mission’s Crew Dragon spacecraft reached an altitude of 1,400 kilometers, the highest orbit above Earth achieved by a manned spacecraft and the farthest distance humans have traveled from Earth since NASA’s Apollo missions in the late 1960s and early 1970s. And earlier today, two of its crew members, US entrepreneur Jared Isaacman and SpaceX engineer Sarah Gillis, completed the first commercial spacewalk at an altitude above 700 kilometers.

SpaceX sends astronauts into space – and ushers in a new era of private manned space travel

“We all still have a lot of work to do at home, but from here, Earth really does look like a perfect world,” Isaacman said as he stuck his head and torso out of the spacecraft’s hatch, preparing for his spacewalk maneuvers.

While these milestones are impressive, what the researchers who spoke to us found even more fascinating Nature is what the mission could mean for the future of space exploration. As more private individuals and flights into space increase, there will be more opportunities to conduct experiments in microgravity and explore the limits of human spaceflight.

“It’s probably the most exciting time in space travel since the 1960s,” says Christopher Mason, a geneticist at Weill Cornell Medical College in New York City who heads the Space Omics and Medical Atlas (SOMA), a major repository of astronaut biomedical data. “Now we have spacesuits, spacecraft and a mission all coming from a private company, SpaceX, which is really the first time we’ve had this completely independent organization of space travel.”

Space mechanics

If civilians can complete a spacewalk, it may even mean more opportunities to repair scientific equipment in space. In 2022, Isaacman proposed that NASA use a crewed SpaceX mission to launch the agency’s Hubble Space Telescope into a higher orbit, extending its lifespan. The telescope has been in space for 34 years and will gradually descend until it burns up in Earth’s atmosphere. NASA has rejected the proposal for now, citing the potentially catastrophic risks to both Hubble and the crew.

But with the success of today’s spacewalk – also known as an extravehicular activity, or EVA – the idea of ​​a private company conducting such difficult space operations has become all the more plausible. “If Polaris Dawn is completely successful with its commercial EVA, that would be a step forward and perhaps that would be enough to convince NASA,” says Laura Forczyk, managing director of space consulting firm Astralytical in Atlanta, Georgia.

In the meantime, Polaris Dawn will deliver science results after it splashes down in either the Gulf of Mexico or the Atlantic Ocean in the next few days. The mission’s Crew Dragon spacecraft, called Resilienceis carrying 36 experiments from 31 different institutions from Canada, Saudi Arabia and the United States, many of them focused on astronaut health. “We can learn a lot,” Isaacman said during a press conference on August 19. “If we go to Mars one day, we would like to come back and be healthy enough to tell people about it.”

More crews, more data

Polaris Dawn is the first of three planned Polaris missions funded and led by Isaacman, the chief executive of payment processing company Shift4 based in Center Valley, Pennsylvania. One of the goals of the Polaris program is to advance Hawthorne, California-based SpaceX’s ambitions in human spaceflight. The third Polaris mission will be the first crewed flight of SpaceX’s Starship, a fully reusable mega-rocket that NASA plans to use to transport astronauts to the lunar surface in a few years as part of its ambitious Artemis program.

How a few days in space can mess up a person’s biology

Before then, Polaris Dawn is testing some basic things. For example, it unveiled SpaceX’s EVA suit, the company’s first suit designed to protect humans from the vacuum atmosphere of space. Gillis and Isaacman wore the suits during their spacewalk. “We know that one day someone might wear a version of this suit,” Isaacman said at the Aug. 19 press conference.

The mission also examines the health of the crew members on board. “Spaceflight is simply an enormous stress factor,” says Jimmy Wu, deputy director of the Translational Research Institute for Space Health (TRISH) at Baylor College of Medicine in Houston, Texas, which collects medical data from commercial astronauts, including the crew of Polaris Dawn.

Researchers believe private manned spaceflights will provide answers to how space travel affects health more quickly than government-led missions with trained astronauts because they launch more frequently. “It’s really difficult to study astronauts because it takes so long to get even 10 or 12 of them through six-month missions,” says Leigh Gabel, a kinesiologist at the University of Calgary in Canada who studies the effects of microgravity on bone health. “Private spaceflight could give us a real head start.”

How the body deals with space

Gabel’s team will take high-resolution X-rays of the Polaris Dawn crew’s wrists and ankles after they return to Earth to measure the effects of several days of microgravity on bone structure. Their previous work on astronauts who have spent time on the International Space Station has shown that months of microgravity can cause the internal structure of weight-bearing bones, such as those in the legs, to become so weakened that they do not fully heal even a year after returning to Earth.¹.

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Several researchers are also using Polaris Dawn to better understand spaceflight-associated neuroocular syndrome (SANS), a condition in which astronauts experience permanent changes – or even damage – to their vision. Scientists suspect that SANS is caused by fluid buildup in the eye that would normally drain away due to Earth’s gravity. Working with ophthalmologist Prem Subramanian and space health researcher Allie Hayman of the University of Colorado Boulder, Polaris Dawn crew members are each wearing a “smart” contact lens that can record fluid pressure in the eye.

Other researchers will study the effects of space radiation – high-energy charged particles – on the body by analyzing DNA, RNA and other biosamples taken from the Polaris Dawn crew. Importantly, Polaris Dawn is the first time many of these analyses will be conducted on the same spacefarer in two different missions: Isaacman also participated in SOMA and TRISH research when he led Inspiration4, a purely civilian orbital mission from SpaceX in 2021.

Isaacman is “actually one of the best-characterized people who ever lived,” says Mason. “He is our best chance to understand what happens to the body before a space flight and what happens every time you go into space.”