A SpaceX launch vehicle prototype burst into flames during a test at a Texas launchpad Friday afternoon — a day before the company hopes to send two NASA astronauts into space on another craft in Florida, according to reports and footage of the explosion.

The vehicle erupted soon after a trial known as a static fire test, which initially appeared successful, CNBC reported.

Minutes after the attempt, the prototype burst into flames, video of the blast shows. It’s unclear what caused the explosion.

The blast is a setback for SpaceX owner Elon Musk’s starship project, which is designed to take humans to Mars.

The company earlier this week acquired FAA approval to fly the prototypes on short test runs, TechCrunch reported. It’s now unclear if the test flights will move forward.

SpaceX was scheduled to launch NASA spacemen Doug Hurley and Bob Behnken to the International Space Station from Florida’s Kennedy Space Center Wednesday, but the launch was canceled because of bad weather.

The flight — which would have marked the first time a private company sent humans to space — has been rescheduled for Saturday.