Jan. 7 (UPI) -- SpaceX successfully launched an undisclosed national security payload on Sunday night.
The Falcon 9 rocket launched at approximately 8 p.m. ET from the company's launch pad at Cape Canaveral Air Force Station in Florida. The rocket's first stage was a controlled landing back on Earth at Landing Zone 1.
Falcon 9 first stage has landed at Landing Zone 1. pic.twitter.com/679wN4F8kX- SpaceX (@SpaceX) January 8, 2018
Originally scheduled to launch in November, problems with the rocket caused officials to delay plans by several weeks. Another launch attempt was set for Jan. 4, but the bomb cyclone that brought heavy snow and winds to much of the East Coast last week further delayed the mysterious mission.
The Falcon 9 rocket carried Zuma, a U.S. government spacecraft, into low-Earth orbit. Aside from its name, little is known about the payload. SpaceX's press kit offers no details about the mysterious satellite.
"Everybody involved with the mission is pretty tight-lipped about it," Space.com reported last year.
SpaceX has previously launched a pair of national security-related missions, a spy satellite for the National Reconnaissance Office and the robotic X-37B space plane for the U.S. Air Force. But Sunday's launch is perhaps the company's most secretive yet.
Aerospace and defense company Northrop Grumman was responsible for securing SpaceX's launch services for the Zuma mission.