The first attempt to launch a satellite from western Europe appears to have failed early after an "anomaly" prevented the rocket from reaching orbit.
The mission had left from the coastal town of Newquay in southwest England, with Virgin Orbit's LauncherOne rocket carried under the wing of a modified Boeing 747 and later released over the Atlantic Ocean.
"We appear to have an anomaly that has prevented us from reaching orbit," the company said. "We are evaluating the information."
The apparent failure deals a further blow to European space ambitions after an Italian-built Vega-C rocket mission failed after lift-off from French Guiana in late December.
The rockets have since been grounded.
Virgin Orbit, part-owned by British billionaire Richard Branson, had planned to deploy nine small satellites into lower Earth orbit (LEO) in its first mission outside its United States base.
Launch officials were not immediately available for further comment. The company had earlier said on Twitter that LauncherOne had reached Earth orbit, a tweet it later deleted.
A graphic display on an official video feed showed the mission at second-engine cut-off, three steps short of payload deployment about two hours after take-off.
The carrier aircraft, called "Cosmic Girl", returned to Newquay spaceport shortly after the rocket suffered the anomaly.
#CosmicGirl has returned safely back to @SpaceCornwall with our flight crew.
— Virgin Orbit (@VirginOrbit) January 10, 2023
-Reuters