Live coverage: Falcon 9 disintegrates after launch

Nine Merlin engines at the base of SpaceX’s next Falcon 9 rocket fired up Tuesday on a launch pad in Florida, wringing out the booster and ground systems ahead of a planned liftoff Sunday with a top secret payload for the U.S. government’s spy satellite agency.

The NROL-105 mission is the first of about a dozen missions planned for 2026 that support the NRO’s so-called proliferated architecture satellite constellation. Liftoff from pad 4E at Vandenberg Space Force Base happened at 8:39:51 p.m. PST (11:39:51 p.m. EST / 0439:51 UTC).

NASA has selected a SpaceX Falcon 9 rocket — flying with a reused first stage booster — to launch the Imaging X-ray Polarimetry Explorer mission from pad 39A at the Kennedy Space Center in Florida in April 2021, bypassing Northrop Grumman’s air-launched Pegasus rocket for the task.