The planned Wednesday launch of four civilians on a privately chartered spaceflight featuring the first commercial spacewalk has been delayed again, this time because of predicted bad off-shore weather where the crew capsule will splash down at the end of the flight, SpaceX announced late Tuesday.

SpaceX is set to launch a mission that will not only see humans travel the farthest away from Earth since Apollo 17 in 1972 but also conduct the first-ever commercial spacewalk. This is in addition to nearly 40 different science experiments and an attempt to transmit data from space through the Starlink network.

Polaris Dawn, a private space mission that aims to complete the first-ever civilian spacewalk, is expected to launch this week. SpaceX said it’s targeting Tuesday August 27 at 3:38AM ET for liftoff.