Musk's SpaceX testing breakthrough tech in risky spacewalk

Washington (Reuters): SpaceX's attempt at the first ever private spacewalk next week will be a test of trailblazing equipment, including slim spacesuits and a cabin with no airlock, in one of the riskiest missions yet for Elon Musk's space company.

A billionaire entrepreneur, a retired military fighter pilot and two SpaceX employees are poised to launch on Tuesday aboard a modified Crew Dragon craft, before embarking on a 20-minute spacewalk 434 miles (700 km) into space two days later.

Until now, walking into the empty expanse of space has only been attempted by government astronauts on the International Space Station (ISS), 250 miles (400 km) above Earth.

SpaceX's five-day mission - dubbed Polaris Dawn - will swing in an oval-shaped orbit, passing as close to Earth as 190 km (118 miles) and as far as 1,400 km (870 miles), the farthest any humans will have ventured since the end of the United States' Apollo moon program in 1972.

Crew members, including billionaire Jared Isaacman, will don SpaceX's new, slimline spacesuits in a Crew Dragon vehicle that was modified so it can open its hatch door in the vacuum of space - an unusual process that removes the need for an airlock.

"They're pushing the envelope in multiple ways," retired NASA astronaut Garrett Reisman said in an interview. "They're also going to a much higher altitude, with a more severe radiation environment than we've been to since Apollo."