CAPE CANAVERAL, Florida: Blue Origin suffered a major setback in its effort to challenge SpaceX after an uncrewed New Glenn rocket exploded during a ground test at a Florida launchpad on May 28.

The incident occurred as Jeff Bezos' space company was preparing the rocket for its fourth mission, which was expected to carry 48 Amazon Leo satellites into low-Earth orbit as part of a planned broadband network competing with Elon Musk's Starlink system.

Video footage livestreamed by NASASpaceflight showed the New Glenn rocket igniting during a hot-fire test before erupting into a massive fireball, sending flames and smoke high into the night sky.

A source familiar with the matter said no Amazon Leo satellites had been installed on the rocket at the time of the explosion.

Blue Origin confirmed that an "anomaly" occurred during the hot-fire test, a procedure in which rocket engines are ignited while the vehicle remains secured to the launch pad.

The explosion represents another challenge for the long-delayed New Glenn program, which is expected to play a key role in NASA's Artemis lunar exploration initiative by carrying cargo and lunar landers to support future moon missions.

The setback comes just two days after NASA awarded Blue Origin a US$188 million contract to land rovers on the moon and less than a week after SpaceX conducted a largely successful test flight of its next-generation Starship rocket.

Jeff Bezos acknowledged the setback in a post on X. "Very rough day, but we'll rebuild whatever needs rebuilding and get back to flying. It's worth it," Bezos said, adding that it was still too early to determine the cause of the failure.

NASA Administrator Jared Isaacman said the agency would support Blue Origin's investigation into the incident. "Spaceflight is unforgiving, and developing new heavy-lift launch capability is extraordinarily difficult," Isaacman said on X.

He added that NASA would later provide details about any potential effects on its Artemis and Moon Base programs.

The incident highlights the intense rivalry between Blue Origin and SpaceX as both companies compete for contracts linked to NASA's plans to return astronauts to the moon before China's planned crewed lunar mission in 2030.

SpaceX has also faced high-profile rocket failures. Last year, a Starship vehicle exploded during testing in Texas. More recently, the company successfully deployed mock satellites and completed a controlled splashdown during a Starship test flight, although it failed to recover the Super Heavy booster as planned.

Responding to a video of the New Glenn explosion, Musk wrote on X: "Most unfortunate. Rockets are hard."

Blue Origin has spent billions of dollars and nearly a decade developing New Glenn, a 29-storey reusable rocket designed to compete with SpaceX's Falcon rockets and eventually challenge Starship.

The U.S. Federal Aviation Administration said it was aware of the incident but noted that it fell outside the agency's regulatory scope and did not affect regional air traffic.