A SpaceX capsule carrying four private citizens will have to wait to launch into space after a helium leak forced a launch delay until later this week at the earliest.

Billionaire entrepreneur Jared Isaacman, retired Air Force Lt. Col. Scott “Kidd” Poteet and SpaceX engineers Sarah Gillis and Anna Menon were scheduled to launch into space on a mission that was to include the first spacewalk carried out by a civilian crew.

The mission, known as Polaris Dawn, had been scheduled to lift off…