SpaceX test-fired its next Falcon 9 rocket at NASA’s Kennedy Space Center on Saturday in preparation for the company’s 17th launch of the year, a mission tentatively set for liftoff Wednesday with a secretive payload named Zuma for the U.S. government.

The United Launch Alliance Delta 4-Heavy rocket, standing 235 feet tall and weighing 1.6 million pounds fully fueled, unleashes 2.1 million pounds of thrust from the three RS-68A main engines at 1:51 p.m. EDT (1751 GMT) today to launch from Cape Canaveral on NROL-37.

The opening volley in the transformation of U.S. weather forecasting was mounted atop its ride to space today for the planned Nov. 19 launch that begins an $11 billion upgrade in the nation’s meteorology capability.