CAPE CANAVERAL, Fla. (NewsNation) — SpaceX’s Polaris Dawn mission, poised to make history with the first private spacewalk, was delayed by at least 24 hours.

The mission, a risky endeavor previously undertaken only by government astronauts, originally set to take place Tuesday at NASA’s Kennedy Space Center in Florida, will now occur Wednesday between 3:38 and 7:09 a.m. ET.

If needed, backup opportunities are available Thursday at the same time, SpaceX said.

Why was the mission rescheduled?

SpaceX said the launch was delayed to inspect “a ground-side helium leak” in equipment designed to detach from the rocket during takeoff.

“Falcon and Dragon remain healthy and the crew continues to be ready for their multi-day mission to low-Earth orbit,” Space X wrote in a social media post.

Who are the astronauts doing the spacewalk?

Billionaire Jared Isaacman, who previously flew to orbit with SpaceX in 2021, will be leading the crew, joined by former Air Force pilot Scott “Kidd” Poteet and two SpaceX engineers, Sarah Gillis and Anna Menon.

The Polaris Dawn crew will mark the world’s first-ever civilian spacewalk, set new records for the highest spaceflight by female astronauts and endeavor to reach the highest Earth orbit ever flown since the Apollo program.

Additionally, during the historic mission, the crew will spend five days in orbit, conducting nearly 40 research studies and experiments, including testing new orbital Starlink laser-based communications and new SpaceX-developed EVA suits in Earth’s radiation belts.