SpaceX on Monday postponed the first test flight of Starship, the most powerful rocket ever built, designed to send astronauts to the Moon and Mars and beyond. Liftoff of the gigantic rocket was called off just minutes ahead of the scheduled launch time because of a pressurization issue in the booster stage, SpaceX said. SpaceX founder Elon Musk said a pressure valve appeared to be frozen, forcing a postponement of the launch.
