SpaceX's Polaris Dawn mission, which aims to conduct the first private spacewalk and reach a record altitude of 870 miles, has been postponed to August 28 due to a helium leak detected on ground-side equipment. The mission, led by billionaire Jared Isaacman, includes a crew of four: pilot Scott Poteet, and SpaceX engineers Anna Menon and Sarah Gillis, all of whom have undergone extensive training over two years. This mission is significant as it will venture into the Van Allen radiation belts, marking a new chapter in commercial space exploration. Polaris Dawn is the first of three planned missions under Isaacman's Polaris program, which aims to develop new technologies for future human space travel. The crew's training involved a variety of rigorous simulations and physical challenges to prepare them for the unique environment of space. The launch will take place from NASA's Kennedy Space Center in Florida, with a new launch window set for early Wednesday morning.