BBC's Science Correspondent, Jonathan Amos wrote:Starship took off on time, it took a little while to get off the pad, it was very slow getting away.
It appeared as though when the rocket was climbing up through the sky that some of the engines on the base of the Super Heavy Booster weren't firing. I counted six, out of 33.
Engineers may have made the decision just to shut them down.
They went through Max-Q - the moment when the aerodynamic loads on the vehicle are at their greatest - they survived that, they continued on going.
But it was at that key moment when the bottom half of the rocket -- the Super Heavy Booster - is supposed to separate from the top half of the ship and go on by itself up into space.
They didn't separate, and then the vehicle went into a spin, started to go out of control, and at that point the computers probably triggered the flight termination system.
SpaceX will be thrilled with how far they got - they didn't destroy the launch pad, they got clear and they got tonnes of data.
I think for a first go, they will be amazed at what they achieved. They already have another rocket virtually ready to go, and that rocket has a huge range of improvements on what they learned building this one.