Meet Jared Isaacman, the billionaire leading the SpaceX Polaris Dawn mission

This isn’t Isaacman’s first time in space.

Three years ago, he helped finance and lead a SpaceX ride on the company’s first private manned mission, along with a group of three other civilians.

But its latest mission, called Polaris Dawn, is significant, both because of the spacewalk and because the crew plans to travel further than any mission since the Apollo era. It’s also a particularly risky mission because the crew is set to fly through a radiation belt.

The group had planned to depart from the Kennedy Space Center in Florida earlier this week, although the event was postponed due to weather conditions.

The new launch date remains unknown as the reusable booster on one of SpaceX’s Falcon 9 rockets failed Wednesday while landing on a drone ship at sea. The Federal Aviation Administration is investigating the incident, and SpaceX may need to seek approval for other launches.

Isaacman, meanwhile, said on social media Thursday that the crew was “ready to launch in about 30 hours after receiving a favorable forecast.”

The mission is scheduled to last about five days, and three other non-astronaut crew members plan to join the mission, including retired U.S. Air Force pilot Scott Poteet and SpaceX engineers Sarah Gillis and Anna Menon.