An uncrewed Blue Origin New Glenn rocket exploded on a Florida launch pad during a test on Thursday, in a major setback for Jeff Bezos’ space venture as it seeks to narrow the gap with Elon Musk’s IPO-bound SpaceX.

Video posted by NASASpaceflight, which live-streams launches from Florida, showed the towering New Glenn rocket igniting on the pad before erupting into a massive fireball that billowed skyward, sending a towering plume of flames and smoke into the air.

Blue Origin was preparing the rocket for its fourth launch, which was due to deliver 48 Amazon Leo satellites into low-Earth orbit, part of efforts to build a broadband constellation to rival Musk’s Starlink network. Amazon Leo satellites were not integrated on the rocket at the time of the incident, a source familiar with the matter said, asking not to be named due to its sensitivity.

The explosion marked the latest setback for the long-delayed New Glenn, which is supposed to play a central ⁠role in delivering lunar landers and cargo under Nasa’s Artemis lunar exploration missions.

It came just two days after Nasa awarded Blue Origin a US$188 million contract to land rovers on ‌the moon’s surface, and less than a week after SpaceX – years ahead in development – carried out a largely successful test of its next-generation Starship rocket.

Blue Origin confirmed it had experienced an “anomaly” during a hot-fire test, where a rocket engine is fired up while anchored to ‌the ground.