Musk's SpaceX tests groundbreaking technology in high-risk private spacewalk

SpaceX's five-day mission, called Polaris Dawn, will orbit in an oval shape, coming as close as 190 km (118 miles) to Earth and as close as 1,400 km (870 miles) to it.

This is the furthest distance a human has ventured since the end of the US Apollo moon program in 1972.

“They're pushing the envelope in many ways,” retired NASA astronaut Garrett Reisman said in an interview. “They're also going to go to much higher altitudes, with an environment that's even more exposed to radiation than we've ever experienced since Apollo.”

For SpaceX, the mission is an opportunity to advance technologies that could be used on the Moon and Mars.

Far outside the protective bubble of the Earth's atmosphere, the electronics and shielding of Crew Dragon and spacesuits are tested as they pass through parts of the Van Allen Belt.

In this belt, charged particles, mostly from the sun, can interfere with satellite electronics and harm human health.

“That's an additional risk that you don't face if you just stay in low Earth orbit and go to the ISS,” Reisman said.

Not a “normal” process

The Polaris spacewalk will take place on the third day of the mission, but preparations will begin about 45 hours beforehand.

The entire cabin of the Crew Dragon is depressurized and exposed to the vacuum of space. While only two of the astronauts are floating in the open air, connected to an oxygen line, the entire crew is dependent on their spacesuits to remain life-supporting.

A few days before the spacewalk, the crew begins a “pre-breathing process” to fill the cabin with pure oxygen and remove any nitrogen from the air.

If nitrogen is present in the bloodstream of astronauts in space, it could form bubbles, block blood flow and lead to decompression sickness, which occurs in recreational divers who return to the water surface too quickly.

The crew will monitor the formation of bubbles using an ultrasound device, one of many instruments the mission will use to conduct dozens of scientific experiments.

This will give researchers a rare insight into the fate of astronauts on the lunar surface or elsewhere in space.

“It gives us a unique opportunity to test these vehicles in such a unique environment,” said Emmanuel Urquieta, vice chair of aerospace medicine in the Department of Internal Medicine at the University of Central Florida.

There are no corresponding standards or laws in the USA regarding the safety of private space flights such as Polaris.

Normally, the safety of astronauts on NASA missions is closely monitored by the agency.

Officials from SpaceX and the Polaris crew said during a press conference on August 19 (Monday) that they have planned a number of emergency scenarios in case something goes wrong during the mission.

Reisman said he knows the Polaris crew and is confident they are prepared for any unexpected mishaps.

“But there is not much room for error,” he explained

Reuters contributed to this report.