As Elon Musk-led SpaceX's first all-civilian crew launched into Earth's orbit, tech billionaire Jared Isaacman thanked everyone who made possible a journey "right to the doorstep of an exciting and unexplored frontier". "Few have come before...many are about to follow. The door is open now, and it's pretty incredible," the 38-year-old said. Isaacman was aboard the spaceflight with three others.