India, May 29 -- An uncrewed Blue Origin New Glenn rocket erupted in a towering fireball on its launch pad during a ground test on Thursday night, destroying a brand new booster and dealing a heavy blow to Jeff Bezos's effort to close the gap with Elon Musk's SpaceX.

The blast tore through Launch Complex 36 at Cape Canaveral Space Force Station at about 9 p.m. Eastern time, while the company was running a hotfire test, a procedure in which a rocket's engines are ignited at full thrust as the vehicle stays bolted to the ground. Live video from the pad showed New Glenn igniting before a wall of flame and smoke climbed into the night sky. Residents in Cape Canaveral and nearby Cocoa Beach reported hearing and feeling the explosion.

Blue O...