SpaceX's Polaris Dawn mission, initially scheduled for launch on Tuesday, has been delayed by at least a day due to a helium leak in ground equipment at Kennedy Space Center. The launch of the Crew Dragon capsule, carried by a Falcon 9 rocket, is now planned for 3:38 AM (0738 GMT) on Wednesday.

The five-day Polaris Dawn mission aims to conduct the first-ever private spacewalk, which will occur two days after launch. The crew, including billionaire Jared Isaacman, retired Air Force Lieutenant Colonel Scott Poteet, and SpaceX engineers Sarah Gillis and Anna Menon, will test new SpaceX spacesuits during the spacewalk. They will reach a peak altitude of 870 miles (1,400 kilometers) and briefly enter the Van Allen radiation belt.

The mission will also involve testing laser-based communication with Starlink satellites and conducting experiments on human health in space. The mission will conclude with a splashdown off the coast of Florida. Polaris Dawn is the first of three missions in the Polaris program, which aims to test new technologies and operations for future space exploration.