A prototype rocket exploded shortly after launching on a test flight from a base in central Texas, according to the company that launched it.
A statement on the SpaceX website said: "During the flight an anomaly was detected in the vehicle and the flight termination system automatically terminated the mission."
The explosion was wintessed by one Twitter user.
No one was hurt during the experiment which the company said had pushed the vehicle to limits further than any previous test.
They added: "With research and development projects, detecting vehicle anomalies during the testing is the purpose of the program."