Falcon 9 abort seen from press site

A pair of European-built, NASA-backed research satellites set for launch Tuesday from California will extend 15 years of global gravity field measurements collected by the GRACE mission before it ended last year, supplying scientists with data to help track the melting of Earth’s ice sheets and chart the impacts of floods and droughts.

The mission will bring SpaceX close to having 7,000 Starlink satellites in low Earth orbit. Liftoff from pad 40 at Cape Canaveral Space Force Station is set for 5:05 p.m. EST (2205 UTC).

NASA Administrator Jim Bridenstine visited SpaceX’s California rocket factory Thursday, toured the sprawling facility with founder Elon Musk and told reporters he is optimistic the company will be ready to launch the first piloted test flight of its Crew Dragon spaceship in the first quarter of next year.