A SpaceX rocket has exploded in a dramatic fireball after a test.
It is just the latest in a series of spectacular failures of prototypes of the Starship heavylift rocket.
The Starship was being used in ground tests at the company's south Texas test facilities, as part of an attempt to rush the large metal rocket into flight.
The explosion occurred hours before an unrelated launch that will see Elon Musk's space company launch two Nasa astronauts from Florida's Kennedy Space Center using a different rocket system, the Falcon 9 with the Crew Dragon capsule fixed on top.
A prototype vanished in an explosive fireball at SpaceX's Boca Chica test site on Friday, as seen in a livestream recorded by the website NASA Spaceflight. There was no immediate indication of injuries.
SpaceX did not immediately respond to a request for comment.
Starship, a rocket standing 394 feet tall, is designed to carry humans and 100 tons of cargo to the moon and Mars. It is the space company's planned next-generation fully reusable launch vehicle, the centre of Musk's ambitions to make human space travel affordable.
In March, Mr Musk shared new images of the prototype, following a string of explosions that destroyed previous versions of the Starship rocket.
The south Texas facility sits beside a small neighborhood that SpaceX has been trying to buy up for testing space, but some residents have pushed back on the company's offers and have accused Musk's attorneys of unrealistically low property appraisals.
SpaceX was among the three companies awarded a combined $1 billion by NASA last month to develop rocket systems capable of ferrying cargo and humans to the moon. SpaceX proposed Starship for the award.
The FAA granted the space company a license Thursday to begin Starship's first suborbital flight tests, though it was unclear when those tests would occur.
Additional reporting by Reuters
