SpaceX's historic Polaris Dawn mission was delayed by at least 24 hours on Monday after a helium leak, the aerospace company announced Monday night.
The capsule, carrying four citizens, was expected to lift off early Tuesday from NASA's Kennedy Space Center in Florida, but a helium leak pushed the launch until no earlier than Wednesday.
"Teams are taking a closer look at a ground-side helium leak on the Quick Disconnect umbilical," the company wrote on X. "Falcon and Dragon remain healthy, and the crew continues to be ready for their multi-day mission to low-Earth orbit."
Those expected on the mission include retired Air Force Lt. Col Scott “Kidd” Poteet, SpaceX engineers Sarah Gillis and Anna Menon and Jared Isaacman, a billionaire adventurer who chartered the first commercial flight to orbit aboard a SpaceX Crew Dragon in 2021.
"We're officially scrubbed for today, but the @SpaceX team is doing awesome work to ensure all systems are 100% ready for launch!" Gillis wrote on X Monday.
Polaris Dawn is the first of three planned missions in the Polaris Program, a human spaceflight project funded by Isaacman. In the first mission, the Polaris Dawn crew will spend up to five days in orbit in hopes of reaching the highest Earth orbit ever flown and conducting a spacewalk.
The spacewalk is expected to occur on the third day, during which two crew members will exit the Crew Dragon spacecraft on a tether in newly designed suits, per NBC News, while about 700 kilometers above Earth.
The mission is "designed to advance both human health on Earth and our understanding of human health during future long-duration spaceflights," per the program's website. This includes using ultrasound to detect "venous gas emboli," along with gathering data to better understand the effects of space radiation on human biological systems, along with other goals.
It will also mark the first to test Starlink laser-based communications in space, according to the program website.