SpaceX not to blame for secret Zuma satellite flop: Sources

Sources told ABC News satellite builder Northrup Grumman is to blame.

SpaceX President and COO Gwynne Shotwell from the very beginning asserted that the company's Falcon 9 rocket performed as expected: “For clarity: after review of all data to date, Falcon 9 did everything correctly."

The launch was the first of the year for SpaceX but it was shrouded in such mystery because of the top-secret nature of its payload, code-named Zuma.

Rocket launches are tough – the history of spaceflight has multiple incidents of explosions and SpaceX has had its fair share of failures.

One rocket bound for the space station disintegrated shortly after launch destroying supplies headed for the space station.

Another exploded on the launch pad during a static fire test. Landing rockets is even harder though SpaceX has racked up several successes.

But given the secrecy surrounding the Zuma launch most of the details of the failure will remain a closely guarded secret.