But the company is still claiming that New Glenn will return to flight this year.

The explosion is likely a major setback for Jeff Bezos' spaceflight company, and its attempt to compete with SpaceX.

Jeff Bezos' rocket company confirmed an engine failure led to the loss of an AST SpaceMobile satellite last month, but offered little detail.

The New Glenn rocket will have to stay grounded while the company investigates what caused the apparent failure of its upper stage.

It's a major milestone for the company's new mega-rocket system, putting it in position to challenge SpaceX's dominance of the global launch market.