The launch was originally scheduled to take place in November, but was scrubbed due to a rocket fairing issue. Another launch attempt was set for January 4, but the bomb cyclone that brought heavy snow and winds to much of the East Coast last week further delayed the mysterious mission.
SpaceX tweeted that weather conditions are now 80 per cent favourable for Monday, and that it's completed yet more pre-launch testing, so all looks as good to go on paper as firing a giant canister of rocket fuel and secret technology into the sky can be.
About 8 minutes later, the first stage of the Falcon 9 rocket came in for a lovely night landing at a launch pad back at the Cape. This is SpaceX's third classified mission, and arguably its most secretive flight for the United States military. After the launch, the rocket's first stage will attempt to make a return to a landing site along the Florida coast for what would be the company's 21 rocket landing.
SpaceX will attempt to launch a Falcon 9 rocket from Cape Canaveral Air Force Station tonight.
The second stage continued carrying the mysterious Zuma to its destination in low-Earth orbit (LEO), while the first stage began maneuvering its way back to terra firma for a touchdown at Landing Zone 1, a SpaceX facility at Cape Canaveral.
SpaceX just sent a secret government mission to space. SpaceX is expected to cut off its popular live stream early to hide the spacecraft's final destination.