Polaris Dawn crew prepares for historic spacewalk on Thursday

Billionaire Jared Isaacman and SpaceX crew trainer Sarah Gillies plan to open the forward hatch of their ship Polar Dawn On Thursday morning, the spacecraft will take turns going into outer space as part of the first non-governmental spacewalk in the history of space exploration.

While crew members Anna Menon and Scott Poteet monitor tethers and umbilicals inside the SpaceX Crew Dragon capsule, Isaacman and Gillies plan to spacewalk after the spacecraft depressurizes around 2:23 a.m. ET, using the “Skywalker” scaffolding structure protruding from the hatch for stability.

While their feet will be just outside the hatch, they won’t be “free floating” away from the Crew Dragon. Their SpaceX-designed spacesuits don’t have their own oxygen supply or other life support equipment, and rely on 12-foot umbilicals for air, power, and communications.

An artist's rendering of a Polaris Dawn astronaut flying alongside a Crew Dragon capsule during the first commercial spacewalk. / Credit: SpaceXAn artist's rendering of a Polaris Dawn astronaut flying alongside a Crew Dragon capsule during the first commercial spacewalk. / Credit: SpaceX

An artist's rendering of a Polaris Dawn astronaut flying alongside a Crew Dragon capsule during the first commercial spacewalk. / Credit: SpaceX

While Isaacman and then Gillis float just outside the hatch, they will test the comfort and mobility of their pressurized extra-vehicular activity (EVA) suits by moving their arms, hands and legs through a series of positions to see how much effort it takes to perform basic tasks.

“We’re going to use different propulsion systems that the SpaceX team has developed, and it’s going to look like we’re doing a little bit of a dance,” Isaacman said before the launch. “The idea is to learn as much as we can about this suit and feed that back to the engineers so they can inform future suit design efforts.”

Cameras mounted inside and outside Crew Dragon, as well as cameras attached to the astronauts' spacesuits, are expected to provide spectacular views of space and the Earth below as the craft travels in an elliptical orbit with a low point of 121 miles and a high point of 458 miles — 200 miles above the International Space Station.

The goal of the exercise is to eventually create low-cost, easy-to-manufacture spacesuits for use by future commercial astronauts who will fly to the Moon or Mars aboard SpaceX Super Heavy-Starship rockets.

“I think this path to making affordable spacewalking suits that can be scaled up to mass production is very useful,” said Isaacman, who is leading SpaceX’s first fully commercial flight to orbit in 2021. “At some point in the future, there’s going to be an armada of spacecraft going to Mars, and those people are going to have to be able to get out and walk around and do important things.”

Isaacman, Poteet, Menon and Gillis launched Tuesday from Kennedy Space Center aboard a SpaceX Falcon 9 rocket. The crew immediately accomplished the flight's first major goal, climbing to an altitude of 870 miles — higher than any crewed spacecraft since the Apollo moon landings 60 years ago.

The orbit's highest point, or apogee, was then lowered to 458 miles for the spacewalk and the remainder of the five-day mission.

To prevent decompression sickness, also known as the bends, as the crew transitions from sea level pressure to the 5 psi reduced pressure in their spacesuits and back again, flight controllers began a 45-hour process shortly after launch of increasing cabin oxygen levels while slowly reducing air pressure to remove nitrogen from the crew's circulatory systems.

“We don’t expect to encounter (rolls) because a lot of preparation has gone into developing this pre-breathing protocol, which greatly reduces that risk,” said Menon, a former NASA biomedical flight controller. “But we’re prepared if we need to.”

The Polaris Dawn crew looks up through the hatch of the Crew Dragon simulator, framed by a framework known as The Polaris Dawn crew looks up through the hatch of the Crew Dragon simulator, framed by a framework known as

The Polaris Dawn crew looks up through the hatch of the Crew Dragon simulator, framed by a framework known as

Crew Dragon doesn’t have an airlock, and its life support system wasn’t designed to support a spacewalk. The modifications required included “adding a lot more oxygen into the spacecraft so we could supply oxygen to the four suits through the umbilicals throughout the entire spacewalk,” Gillies said.

“There have been improvements and additions to the spacecraft's environmental sensor system to give us really good information both before, during and after exposure to vacuum. And… a completely new system, a nitrogen repression system,” to bring the cabin pressure back up to normal levels after the spacewalk.

Along with the Skywalker scaffolding that extends just behind the front hatch, a power lift system has been added to make it easier to open and close the hatch, and upgraded seals have been installed to ensure a tight seal.

NASA astronaut Ed White performed the first U.S. spacewalk on June 3, 1965, floating free from his Gemini 4 capsule on the end of a long tether. Since then, NASA astronauts, Russian cosmonauts, Chinese taikonauts, and astronauts from space station partner nations have conducted more than 470 government-sponsored spacewalks.

Isaacman said the iconic photos of White floating outside his Gemini capsule with Earth and space in the background were inspiring, but he and Gillies ruled out free-floating Crew Dragon. And that was by design.

“We’re not going to do an Ed White float,” Isaacman told CBS News before the launch. “It might look cool, but it’s not really going to help SpaceX learn much about (the suit’s) performance. It’s not very useful or helpful for figuring out how to operate in a spacesuit.”

To that end, he and Gillis will work on a “matrix” of planned motions to get a feel for how the suit's many joints move under pressure, test the innovative head-up display in the helmet, better understand how air-cooled suits handle the extreme temperatures of space, and a host of other factors.

Polaris Dawn crew (left to right): Anna Menon, pilot Scott Poteet, commander Jared Isaacman and Sarah Gillies. / Credit: SpaceXPolaris Dawn crew (left to right): Anna Menon, pilot Scott Poteet, commander Jared Isaacman and Sarah Gillies. / Credit: SpaceX

Polaris Dawn crew (left to right): Anna Menon, pilot Scott Poteet, commander Jared Isaacman and Sarah Gillies. / Credit: SpaceX

The suit “incorporates all sorts of technology, including a head-up display, a helmet camera, a completely new architecture for joint mobility,” Gillis said. “The suit has thermal insulation throughout the suit, including a copper and indium tin oxide visor that provides both thermal protection and solar protection.”

Plus, she said, “there's all kinds of redundancy, both in the oxygen supply to the suit and in all the valves, all the seals throughout the suit. It's an incredible suit.”

The head-up display, which will project vital data onto the lower left side of the helmet's visor, is a feature not found in NASA spacesuits designed decades ago.

“During the spacewalk, we'll get a sense of our suit, the pressure, the temperature, the relative humidity, and how much oxygen we used during the spacewalk. So those are some key pieces of telemetry. And what's really cool is that in any light, you can still see that.”

The Polaris Dawn mission is the first of three planned by Isaacman in collaboration with Musk. The second flight will be another Crew Dragon mission, and the third will be the first crewed flight of SpaceX's massive Super Heavy-Starship rocket, which is currently being developed in Texas.

It’s unclear how much Isaacman pays for the flights or how much SpaceX has funded itself. When asked if he could share details, the entrepreneur, jet pilot, and adventurer said, “No way.”

The mission, SpaceX's fifth commercial Crew Dragon flight to orbit and the 14th counting NASA flights, is expected to last five days and end with a splashdown off the coast of Florida.

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