SpaceX Polaris Dawn crew prepares for historic private spacewalk: How will it work?

A team of private astronauts is scheduled on Thursday to perform the inaugural private spacewalk in orbit from a SpaceX capsule, evaluating a new series of spacesuits.

The Polaris Dawn mission, SpaceX's most recent and ambitious attempt to expand the limits of commercial spaceflight, launched from Florida on Tuesday. The crew, consisting of a billionaire entrepreneur, a retired military fighter pilot, and two SpaceX employees, has been circling Earth aboard SpaceX's Crew Dragon since then.

The spacewalk is planned to commence at 2:23 am ET (0623 GMT) with the crew at an altitude of 700 km (435 miles). Two astronauts will exit the Crew Dragon while the other two remain inside. The capsule will be fully depressurized, requiring the entire crew to depend on their streamlined SpaceX-designed spacesuits for oxygen.

What is a Spacewalk, how will it work?
"Any time an astronaut gets out of a vehicle while in space, it is called a spacewalk. A spacewalk is also called an EVA. EVA stands for extravehicular activity," according to US space agency Nasa's website.

Astronauts perform spacewalks for various purposes, such as conducting scientific experiments outside their spacecraft. During these walks, they can attach experimental setups to the exterior of the vehicle and study the effects of the space environment on different materials and objects. Additionally, spacewalks allow astronauts to test new equipment and perform maintenance tasks, including repairing satellites or their own spacecraft.

To safely perform a spacewalk, astronauts must wear specialized spacesuits and use safety tethers that resemble ropes. As Nasa explains, "One end is attached to the spacewalker. The other end is connected to the vehicle. The safety tethers keep astronauts from floating away into space."

Only government astronauts with several years of training have done spacewalks in the past. There have been roughly 270 on the International Space Station (ISS) since its creation in 2000, and 16 by Chinese astronauts on Beijing's Tiangong space station.

Crew for the mission
Jared Isaacman, the founder of Shift4, an electronic payment company, is leading the Polaris Dawn mission. Isaacman has also funded the project in collaboration with SpaceX.

This marks Isaacman's second space voyage, following his 2021 mission where he spent three days in low-Earth orbit before splashing down off the coast of Florida.

The crew accompanying Isaacman includes Scott Poteet, a former US Air Force lieutenant colonel, and two SpaceX employees: Anna Menon, a lead space operations engineer, and Sarah Gillis, an engineer responsible for overseeing astronaut training.

What are the objectives of mission?
The Polaris mission's private astronauts will serve as crucial subjects for a wide array of scientific studies focusing on the human body's response to the deep space environment. These studies will contribute to the extensive body of knowledge gained from decades of research on government astronauts aboard the ISS.

The primary objective of the spacewalk, on the other hand, is to evaluate the performance of the newly developed SpaceX spacesuits, which the company designed in-house. SpaceX intends to utilize these suits for various missions, including those in Earth orbit and potentially beyond.

According to Euro News, the EVA spacesuits, specifically designed for this mission, are equipped with cameras and heads-up displays that provide astronauts with real-time information about their suit's status while outside the vehicle. The report also mentioned that the suits incorporate "improved thermal management" to enhance the astronauts' comfort and safety during the spacewalk.