Britain’s groundbreaking bid to launch a satellite into space from its own soil for the first time went awry early Tuesday. Virgin Orbit had planned a “horizontal launch” mission in which a rocket would be carried under the wing of a customized Boeing 747 before being released and ignited over the Atlantic Ocean. Hundreds of people had gathered at Cornwall Airport in southwestern England to watch the rocket-mounted plane take off at around 10:15 p.m.—the announcement that the mission hadn’t gone to plan was announced on an official livestream of the event just before midnight. “We appear to have an anomaly that has prevented us from reaching orbit,” the company said. “We are evaluating the information.” Britain has only ever successfully completed one orbital launch—the Black Arrow rocket launched in Australia in 1971.