Blue Origin’s New Glenn Rocket Explodes on Launchpad (2)

Blue Origin’s New Glenn rocket exploded in a massive fireball while undergoing a test on a Florida launchpad Thursday evening, dealing a major setback to the Jeff Bezos-backed firm in its efforts to challenge a dominant SpaceX.

The firm was preparing the vehicle for its fourth launch, which was slated to deploy a batch of satellites for Amazon.com Inc.’s Leo, a rival satellite network to SpaceX’s Starlink. None of the satellites were on the rocket when it exploded, a spokesperson for Amazon said.

“Very rough day, but we’ll rebuild whatever needs rebuilding and get ...