SpaceX launched its mega rocket Starship on Saturday but lost contact just eight minutes into the flight.
But the rocket's Super Heavy first stage booster exploded over the Gulf of Mexico shortly after detaching.
About 10 minutes into the flight a company broadcaster said SpaceX mission control had lost contact with the vehicle.
"We have lost the data from the second stage... we think we may have lost the second stage," SpaceX's livestream host John Insprucker said.
"The real topping on the cake today, that successful liftoff," said SpaceX commentator John Insprucker.
Commentator Kate Tice added: "We got so much data, and that will all help us to improve for our next flight."
It follows a previous launch in April in which the spacecraft pulverised its launchpad into a crater before exploding at altitude after four minutes.
SpaceX founder Elon Musk hopes the Starship will eventually carry astronauts to Mars and has said that he hopes its development will mean that humans can eventually become a "multiplanetary species".