Photos: Final ULA mission of the year blasts off successfully

On the eve of its scheduled flight for U.S. national security interests, the United Launch Alliance Delta 4-Heavy rocket stands quietly inside the protective gantry at Cape Canaveral’s Complex 37 pad.

Almost exactly three days after taking off a few miles to the north at the Kennedy Space Center on SpaceX’s historic first crew launch, a 15-story-tall Falcon rocket booster returned to Florida’s Space Coast Tuesday aboard a football field-sized drone ship.

A senior SpaceX official said this week that “heat damage” led to the failure of a Falcon 9 booster during a landing attempt Feb. 15, but the company will press on with more launches and will likely surpass the 10-flight threshold on one of its reusable rockets soon. The next Falcon 9 launch, using a booster flying on its eighth mission, is scheduled for liftoff from Florida with 60 more Starlink internet satellites Sunday night.