Watch SpaceX's second attempt at launching astronauts at 3:22PM ET

It’s time for take two. NASA and SpaceX are making their second attempt at launching the Crew Dragon Demo-2 mission after scrubbing the first due to weather, and they’re once again livestreaming the potentially historic event. The launch itself is scheduled for 3:22PM Eastern, although pre-launch coverage is available now and will continue right up to takeoff.

Whether or not it goes ahead is unclear. Much like the original May 27th window, there’s a very real chance the operations team will have to scrub the launch again if the weather conditions are too risky at both the pad and across the flight path. Elon Musk said there was a 50 percent cancellation risk. There at least won’t be as long of a wait if conditions are too rough, though. Another launch opportunity will be available on May 31st at 3PM Eastern.

As before, a successful launch would represent a couple of major milestones. It’d represent the first crewed private spaceflight, of course, but it would also represent the first crewed launch from American soil since the Space Shuttle program came to a close. It’s not a full operational mission, but it effectively represents the start to a new era of spaceflight.