Video: SpaceX Falcon 9 countdown aborted

Unfavorable high-altitude winds above Cape Canaveral on Tuesday kept a SpaceX Falcon 9 rocket loaded with a NOAA space weather observatory on the ground another day.

A rocket recovery team positioned off Florida’s East Coast is standing by for liftoff Sunday of a Falcon 9 launcher with a space weather satellite, but the demanding trajectory of the flight adds more unknowns to the company’s dicey endeavor to land the booster on a ship at sea.

Depending on how you count it, SpaceX launched its 100th kerosene-fueled Merlin 1D rocket engine on a Falcon 9 rocket Feb. 11, underscoring what it says is an accelerated flight regime for the centerpiece of the company’s propulsion shop.