The rocket ignited and made it to space, but at some point during the firing of the rocket's second stage engine, when travelling at a speed of more than 11,000 miles per hour, the system experienced what's described as an 'anomaly', resulting in mission failure.
Nine satellites being carried weren't released into orbit and have been lost -- it's currently uncertain what happened to them. Cosmic Girl and crew returned safely to base after the launch.
In the run up to the launch, the mission was being billed as the historic beginning of a new era for British space flight. While the satellite launch didn't reach orbit, those behind the mission are hailing it as a step forward.
"We have shown the UK is capable of launching into orbit, but the launch was not successful in reaching the required orbit," said Matt Archer, director of commercial spaceflight at the UK Space Agency.
"We will work closely with Virgin Orbit as they investigate what caused the anomaly in the coming days and weeks. While this result is disappointing, launching a spacecraft always carries significant risks," he added.
"The first-time nature of this mission added layers of complexity that our team professionally managed through; however, in the end a technical failure appears to have prevented us from delivering the final orbit," said Dan Hart, CEO of Virgin Orbit.
"Will work tirelessly to understand the nature of the failure, make corrective actions, and return to orbit as soon as we have completed a full investigation and mission assurance process," he added.
Despite the failure to put satellites into orbit, the project still succeeded in using Spaceport Cornwall to ignite and release a rocket into space, something Melissa Thorpe, head of Spaceport Cornwall, said she's "incredibly proud of".
"Today we inspired millions, and we will continue to look to inspire millions more. Not just with our ambition but also with our fortitude. Yes, space is hard, but we are only just getting started," she said.