The SpaceX capsule, which will carry four commercial astronauts planning to make a historic spacewalk, will not launch until at least Wednesday morning.

Initially set for a launch on Tuesday, the Polaris Dawn mission’s departure was postponed after a helium leak was revealed, according to SpaceX’s announcement on social media platform X.

This mission marks the second spaceflight for billionaire entrepreneur Jared Isaacman, who is financing the project alongside Elon Musk’s SpaceX. Isaacman first ventured into orbit during the 2021 Inspiration4 mission, which was significant as the inaugural private orbital spaceflight.

Isaacman will lead a team that features pilot Scott “Kidd” Poteet and engineers Sarah Gillis and Anna Menon, both serving as mission specialists. The Polaris Dawn crew aims to ascend to altitudes that have not been reached by humans since NASA’s Apollo missions in the 1970s and to carry out the first commercial spacewalk.

When is Polaris Dawn launching?

The Falcon 9 rocket, which is carrying the Dragon capsule, is scheduled to launch between 3:38 and 7:09 a.m. ET on Wednesday from NASA’s Kennedy Space Center in Florida.

The launch delay, which marks the second postponement since the Polaris Dawn crew arrived in Florida last week, was necessary for ground teams to investigate “a closer look at a ground-side helium leak” affecting equipment that detaches from the rocket during launch, SpaceX stated on X.

Similarly, the Boeing Starliner spacecraft, which competes with SpaceX’s Dragon for NASA’s approval for routine orbital flights, also encountered a helium leak en route to the International Space Station. This leak, along with thruster malfunctions, caused NASA to cancel the crew’s return journey to Earth aboard the Starliner.

Despite the helium leak issues, SpaceX seems confident that it won’t impact the imminent launch of its reliable spacecraft, which has been successfully transporting astronauts to orbit since 2020.

“Falcon and Dragon are in good condition, and the crew is fully prepared for their mission to low-Earth orbit,” the company announced.

If there are further delays, the launch could still be pushed to Thursday morning, as indicated by SpaceX.

What does the Polaris Dawn mission entail?

The crew intends to spend five days in orbit, testing technology for SpaceX that could be vital for NASA and other space agencies as they aim for deep-space missions, including those to Mars.

On their first day in orbit, the crew plans to ascend to a height of 870 miles, which is higher than any human has journeyed since the end of NASA’s Apollo lunar missions in the 1970s. The path will take the capsule through the challenging inner layers of Earth’s Van Allen radiation belts before settling into a cruising altitude of approximately 435 miles above Earth.

The Van Allen belts present a significant challenge for future space travelers as they venture deeper into space. For successful missions to the moon and Mars, astronauts will need to navigate through these radiation belts safely.

While in orbit, the team plans to conduct around 40 scientific experiments, primarily aimed at understanding how the human body responds to extended space travel, and to test a new laser-based satellite communication system with Starlink.

Menon, from Houston, plans to read a children’s book she co-authored, titled “Kisses from Space,” inspired by her preparation for the Polaris Dawn mission, to her two young kids during the journey.

On the sixth day, the SpaceX vehicle will return to Earth and splash down at one of seven designated sites off the coast of Florida.

Performing a Daring Spacewalk

The highlight of the Polaris Dawn mission is sure to occur on day three, when the crew aims to be the first private astronauts in history to carry out a spacewalk.

The intricate orbital maneuvers planned for this mission have only previously been executed by spacecraft equipped with airlocks that prevent the need to depressurize the entire vehicle.

However, the SpaceX Dragon does not feature an airlock, meaning the whole spacecraft must be depressurized when the hatch is opened. While only Isaacman and Gillis are scheduled to exit, all four astronauts will face exposure to the vacuum of space.

Therefore, the entire crew will don Extra-Vehicular Activity (EVA) suits created by SpaceX, which deliver oxygen via tethers. This operation is expected to take roughly two hours and aims to assess the capabilities of the suits for SpaceX.