Billionaire's Crew Prepares for Challenging SpaceX Flight

The crew has arrived in Cape Canaveral to prepare for SpaceX's next private flight, a free-flying, challenging five-day mission that is to include a spacewalk. Polaris Dawn is the first flight of three that billionaire Jared Isaacman bought two years ago for his human spaceflight effort called the Polaris Program, CNBC reports. This mission, commanded by Isaacman, has a full agenda. "He's not just going for a joyride," said Garrett Reisman, a former NASA astronaut and current SpaceX consultant, per CNN. "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."

The earliest liftoff date is Aug. 26. Isaacman's crew is Scott Poteet, a former Air Force pilot, and SpaceX engineers Sarah Gillis and Anna Menon. Their goal is to test technology, including spacesuits, that SpaceX can use to take people deeper into space. The Crew Dragon capsule will reach greater altitudes than any human has seen since the days of NASA's Apollo program, and the orbital path will be high enough to plunge the crew members into a radiation belt, per CNN. That will increase the risk factor. Once they reach space, preparations will begin for the spacewalk. Here's that plan, altered from the usual because there's no airlock:

• Crew members go through a "pre-breathe" process, something like what scuba divers do to avoid decompression sickness. They will have to purge nitrogen from their blood so that when the capsule is depressurized and exposed to the vacuum of space, the gas doesn't form bubbles in their bloodstream, which could be fatal.
• The process, which Gillis said involves "slowly decreasing cabin pressure and raising oxygen concentration," takes about 45 hours.
• On Day 3, once the capsule is about 435 miles above Earth, the crew will open the hatch. Although only Isaacman and Gillis will leave the spacecraft, the other two crew members and the spacecraft's interior will be exposed to space at that point.

(More SpaceX stories.)