SpaceX said Monday it has delayed by a couple of months the return to flight of its Falcon 9 rocket, following an explosion on the way to the space station in June.

The company's chief executive, Elon Musk, had said previously that the rocket would launch no earlier than September, after a failed strut was blamed for the rocket's demise just minutes after takeoff on June 28 from Cape Canaveral, Florida.

"It's taking more time than we originally envisioned to get back to flight," SpaceX chief operating officer Gwynne Shotwell told a spaceflight conference in Pasadena, California.

"We're a couple of months away from the next flight."

The blast destroyed what was supposed to be a routine cargo mission to the International Space Station and caused NASA at least $110 million in lost equipment.

Musk, the billionaire cofounder of PayPal who also heads Tesla Motors, said that SpaceX had had a seven-year record of safety in flight until the accident happened.

Shotwell said the problem was relatively easy to fix, and that engineers were just being extra cautious in the hunt for other potential issues.

"What we wanted to do was to take advantage of the lessons that we learned from that particular failure and make sure we're not seeing something like that anywhere throughout the vehicle," she said at the American Institute of Aeronautics and Astronautics' Space conference.