Watch Video | SpaceX's Zuma secretive government spacecraft launched into low orbit

SpaceX on Sunday blasted off a mystery-shrouded payload known as Zuma into orbit, the media reported. It is a Government spacecraft that is thought to be a satellite, was built by Northrop Grumman after being funded by an unknown arm of the US government for a mysterious mission to be launched into a low orbit by SpaceX.

Northrop Grumman communications director Lon Rains said: "The Zuma payload is a restricted payload. It will be launched into Low Earth Orbit."

“Three, two, one, ignition and lift-off,” said a SpaceX commentator as the Falcon 9 rocket launched under cover of darkness from Cape Canaveral, Florida, at 8:00 pm (0100 GMT Monday).

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The launch was initially scheduled to take place in November but was postponed. SpaceX gave a couple reasons for the schedule changes.

The company said it delayed the mission for "fairing testing". The fairing is the very top portion of the rocket that houses the payload. "Extreme weather" also slowed down the firm's launch preparations.

Earlier, SpaceX has launched national security payloads, including a spy satellite for the National Reconnaissance Office, and an X-37B space plane for the US Air Force.

When asked about the project in November, Northrop Grumman (NOC) -- the Virginia-based aerospace and defence company that built the spacecraft -- declined to give any details about which arm of the government funded it.

"The US government assigned Northrop Grumman the responsibility of acquiring launch services for this mission," the company said in a statement.

"Northrop Grumman realizes this is a monumental responsibility and we have taken great care to ensure the most affordable and lowest risk scenario for Zuma."

SpaceX completed a record 18 launches last year, and it plans to do even more this year, according to spokesman James Gleeson.

Later this month, the company plans to debut its latest invention: The Falcon Heavy, a monstrous rocket will have three times the thrust of the Falcon 9.