SpaceX to launch Polaris Dawn flight featuring billionaire crew member, first commercial spacewalk

Jared Isaacman's first SpaceX flight raised more than $250 million for St. Jude Children's Research Hospital .

SpaceX founder Elon Musk : "This will be the first spacewalk by a commercial company and the furthest from Earth anyone has traveled in over half a century !" Crew Dragon spacecraft will carry Isaacman and his three crewmates to a record high altitude for an Earth -orbit mission.

Crew Dragon will be released to fly on its own in an initial orbit with a high point, or apogee, of 745 miles .

The International Space Station flies in a circular orbit at an altitude of about 260 miles .

As the crew checks out the Crew Dragon's systems, flight controllers will start a 45-hour process to boost oxygen levels in the cabin while slowly decreasing air pressure to help remove nitrogen from the crew's bloodstreams.

Isaacman and Gillis will work through a "matrix" of planned motions to get a feel for how the suit's multiple joints move while pressurized.

They will test the performance of an innovative heads-up display in the helmet.

Isaacman: "We're not going to be doing the Ed White float" The day after the spacewalk, flight controllers plan to test a new laser link with SpaceX's constellation of internet satellites in low- Earth orbit.