The unmanned Starship, the largest rocket system ever built, lifted off from the SpaceX port in Texas on Thursday for a third test flight after two failed previous attempts, according to live-streamed images.
The test flight of the system developed by billionaire Elon Musk's space company was scheduled to last about one hour, with both rocket stages set to conduct a controlled landing in the sea afterwards.
During a first test last April, the entire missile system exploded after just a few minutes. During a second test in November, the two rocket stages separated and the upper stage continued to fly, but shortly afterwards both exploded separately.
The Starship - consisting of the approximately 70-metre-long Super Heavy booster and the approximately 50-metre-long upper stage, also called Starship - was designed to enable manned missions to the moon and Mars.
The system has been developed in such a way for the spaceship and rocket to be reused after returning to Earth. Starship, which is around 120 metres long in total, should be able to transport well over 100 tons of cargo in future.
US space agency NASA wants to use the system to take astronauts to the moon, while SpaceX hopes to reach Mars one day.