After suffering a delay for a month while a small hydrogen leak was repaired, a United Launch Alliance (ULA)-operated Delta IV Heavy rocket successfully lifted off from the Vandenberg launch site. Lifting off at 1910 GMT on 19 January 2019, the rocket placed a mystery satellite dubbed NRO-L71 for the US National Reconnaissance Office into a near polar 74 degree inclination low Earth orbit.  The Lockheed Martin-built spacecraft is believed to be a very high resolution electro-optical imaging Key Hole 12/Improved Crystal-type satellite.

NRO L-71 is sent on its way on a Delta IV Heavy. Courtesy: ULA