SpaceX plans to send four people into Earth orbit as soon as Wednesday in a daring mission that will test new technology, expose astronauts to high levels of radiation, and potentially change how future spacewalks are conducted.
The privately funded mission, called Polaris Dawn, will be led by billionaire Jared Isaacman, who participated in and funded the first private, all-civilian space mission in 2021. Polaris Dawn will also include SpaceX engineers Sarah Gillis and Anna Menon, as well as former Air Force pilot Scott Poteet. The mission was scheduled to launch Tuesday, but the flight was delayed due to a helium leak. The team will spend five days aboard SpaceX’s Crew Dragon vessel, and will travel 870 miles away from Earth, in the farthest crewed mission since 1972’s Apollo 17 spaceflight to the moon.
That distance will put the craft more than 200 miles inside the Van Allen radiation belts — regions in space that encircle the planet and are highly radioactive. They were detected on the first US space mission, in 1958, and their highly charged, energetic particles can damage spacecraft instruments.
The tech aboard the capsule will have to withstand that radiation — as will the astronauts. Two members of the crew, Isaacman and Gillis, will exit their vehicle via a hatch that exposes the entirety of the capsule to space, rather than through an airlock, as astronauts typically do.
The passengers will acclimate to depressurized conditions over the course of about 45 hours to avoid getting nitrogen bubbles in their bloodstreams — which can be deadly.
All of the crew, and all of the systems onboard, need to be able to withstand radiation; each of the passengers need to don SpaceX’s new spacesuits before Isaacman and Gillis start their walk. The capsule underwent rigorous testing on Earth to ensure the radiation wouldn’t fry its circuits, stranding the astronauts. But testing the equipment on the ground isn’t the same as putting it in space, and SpaceX hopes the mission will provide valuable information about how to construct instruments and spacecraft for future missions.
That’s of particular importance for future missions to the moon and beyond — computers have advanced a lot since the ’70s, the last time humans had to deal with the level of Van Allen radiation the Polaris Dawn crew could face.
“Our current technology is ever more susceptible to these accelerated particles because even a single hit from a particle can upset our ever smaller instruments and electronics,” David Sibeck, Van Allen Probes mission scientist at NASA’s Goddard Space Flight Center, told Space Center Houston in a 2020 interview. “As technology advances, it’s actually becoming even more pressing to understand and predict our space environment.”
Crucially, Isaacman and Gillis will also test how protective their suits are when they venture out of the Crew Dragon.
These suits were designed in just two and a half years — an astonishingly quick turnaround by space exploration standards — and are meant to be upgrades to the bulky suits NASA has made famous. Rather than having life support systems integrated into the suit, like in NASA’s, Space X’s new suits connect to the spacecraft via a tube — that’s how Isaacman and Gillis will be able to breathe and function while performing their spacewalk.
Besides radiation, the suits may also need to withstand microimpacts. There are all manner of small objects whizzing in Earth’s orbit at around 17,000 miles per hour; a puncture could be catastrophic. The suits were put through debris testing on Earth, but just like with the instruments, controlled tests are different from the real thing.
SpaceX argues that the mission should go on despite the risks because of all the knowledge there is to gain. Should the flight be successful, humans will obtain a lot of fresh data on how Van Allen radiation affects our latest technology and our bodies; astronauts may gain an alternative way to do spacewalks; and scientists will have a lot to dissect about spacesuit design.
And that’s not to mention the impact the mission could have on long-term goals to send humans back to the moon and Mars.
SpaceX has specifically highlighted the importance of its new suit in making that happen, writing on its website, “The development of this suit and the execution of the spacewalk will be important steps toward a scalable design for spacesuits on future long-duration missions as life becomes multiplanetary.”
SpaceX has said it doesn’t plan to stop here: Polaris Dawn is part of the Polaris Project, which will include two subsequent missions — all of which Isaacman is funding in conjunction with the company.
