October 15, 2024
1 Solar System Way, Planet Earth, USA
Space

First non-governmental spacewalk goes smoothly for Polaris Dawn crew – Spaceflight Now

Isaacman floats above the Crew Dragon hatch and enjoys a spectacular view of Earth from 735 kilometres above the southern Indian Ocean. Image: SpaceX.

In another SpaceX first, billionaire Jared Isaacman and the company's crew trainer, Sarah Gillis, took turns floating outside their Crew Dragon capsule early Thursday in the first privately funded spacewalk in the history of space exploration.

As he gazed at the unobstructed Earth for the first time, 450 miles away, Isaacman marveled at the serene, unbounded view and said, “At home, we all have a lot of work to do, but from here, it sure looks like a perfect world.”

With Polaris Dawn crewmates Anna Menon and Scott Poteet monitoring safety cables and umbilical cords inside the airless, hatch-open SpaceX Crew Dragon, Isaacman floated into open space around 6:51 a.m. EDT, using a “Skywalker” scaffolding-like frame for stability.

While his feet were just outside the hatch, he did not “free-float” away from Crew Dragon. The Space-X-designed pressure suits were not equipped with their own oxygen supply or other life-support equipment and relied instead on 12-foot-long umbilicals to supply air, power and communications.

As Isaacman and then Gillis floated one at a time just outside the hatch, they tested the comfort and mobility of their pressurized extravehicular activity, or EVA, suits by moving their arms, hands and legs through a series of positions to find out how much effort it takes to perform basic tasks.

“We’re going to be using a number of mobility aids that the SpaceX team has designed, and it will feel like we’re dancing a little bit,” Isaacman said before launch. “The idea is to learn as much as we can about this suit and communicate that back to the engineers to inform future evolutions in the suit design.”

Cameras mounted inside and outside the Crew Dragon, along with others attached to the spacewalkers' helmets, provided wide-angle views of space and Earth below as the craft navigated an elliptical orbit with a low point of 121 miles and a high point of 458 miles — 200 miles higher than the International Space Station.

“It's beautiful,” Isaacman said, taking a moment to take in the view after performing his share of mobility tests.

The goal of the one-hour, 46-minute spacewalk was to help company engineers perfect low-cost, easy-to-manufacture spacesuits for use by future commercial astronauts flying to the Moon or Mars aboard SpaceX's Super Heavy-Starship rockets.

Sarah Gillis, SpaceX engineer and crew trainer, climbs through the forward hatch of Dragon Resilience. Image: SpaceX.

“Building a base on the Moon and a city on Mars will require thousands of spacesuits,” SpaceX said on its website. “The development of this suit and the EVA performed on this mission will be important steps toward a scalable design for spacesuits on future long-duration missions.”

Isaacman, Poteet, Menon and Gillis blasted off Tuesday from Kennedy Space Center aboard a SpaceX Falcon 9 rocket. The crew accomplished the flight’s first major objective right away, ascending to an altitude of 870 miles — higher than any crewed spacecraft since the Apollo lunar program 60 years ago.

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

To prevent decompression sickness, or “bends,” as the crew transitioned from sea-level pressure to the reduced 5 psi pressure in their spacesuits and back again, flight controllers began a 45-hour process shortly after launch to increase cabin oxygen levels while slowly decreasing air pressure to help remove nitrogen from the crew's bloodstream.

“We don’t anticipate experiencing it (the curves), because a lot of preparation has gone into developing this pre-breathing protocol, which significantly reduces that risk,” said Menon, a former NASA biomedical flight controller. “But we are prepared if we need to.”

The Crew Dragon has no airlock and its life support system was not designed to support spacewalks. Necessary modifications included “adding a lot more oxygen to the spacecraft so we can supply oxygen to four suits via umbilicals throughout the spacewalk,” Gillis said.

“There have been improvements and expansions to the spacecraft’s environmental sensor suite to ensure that we have really good vision, both before, during and after exposure to vacuum. And… a completely new system, a nitrogen repression system” to increase cabin pressure back to normal after the spacewalk.

Along with the Skywalker scaffolding, which extends just beyond the forward hatch, a motor drive system was added to assist with opening and closing the hatch and improved seals were fitted to ensure a watertight fit.

On March 18, 1965, astronaut Alexei Leonov performed the first spacewalk, followed three months later by NASA astronaut Ed White, the first American astronaut to perform a spacewalk. Since then, NASA astronauts, Russian cosmonauts, Chinese astronauts, and astronauts from space station partner countries have performed more than 470 government-sponsored spacewalks.

Isaacman said the iconic photos of White floating outside his Gemini capsule with Earth and space as a backdrop were inspiring, but he and Gillis ruled out the possibility of floating outside the Crew Dragon. And that was intentional.
“We’re not going to do the Ed White flight,” Isaacman told CBS News before the launch. “It may look cool, but it doesn’t help SpaceX learn a lot about (spacesuit) performance. It’s not very useful or helpful in understanding how you can work with a suit.”

To do so, he and Gillis worked through a “matrix” of choreographed movements to get a sense of how the suit's multiple joints move while pressurized, to test the performance of an innovative helmet-mounted heads-up display, to better understand how air-cooled suits deal with the extreme temperatures of space, and a variety of other factors.

The suit “includes all sorts of technology, including a heads-up display, a helmet-mounted camera, and a completely new architecture for joint mobility,” Gillis said. “There’s thermal insulation throughout the suit, including a copper indium tin oxide visor that provides thermal and solar protection.”

Plus, he said, “There are all kinds of redundancies, both in the oxygen supply to the suit and in all the valves and all the seals in the suit. It’s an incredible suit.”

The heads-up display, which will project critical data onto the lower left side of the helmet's visor, is a feature that NASA's decades-old space station suits do not have.

“During the EVA, we will have information about our suit, the pressure, the temperature, the relative humidity, and also about the amount of oxygen we have used during the EVA. So there we have some key telemetry data. And it’s really cool that, in any lighting, you can still see it.”

The Polaris Dawn mission is the first of three planned by Isaacman, an entrepreneur and philanthropist who owns and flies his own MiG-29 fighter jet, in cooperation with Musk. The second flight will be another Crew Dragon mission, while the third will be the first crewed flight of SpaceX’s massive Super Heavy-Starship rocket, currently under development in Texas.

It's not known how much Isaacman is paying for the flights or how much SpaceX has funded on its own. Asked if he could share any details about Polaris Dawn's funding, Isaacman said “there's no chance.”

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

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