Q&A with Sara Seager, deputy director of science on NASA’s TESS mission (members only)

A SpaceX Falcon 9 rocket fired its nine first stage engines for a brief hold-down firing Friday at Cape Canaveral, passing a key milestone before launch July 24 with a Dragon space station resupply ship.

Keeping with its mantra of fly, fix and fly again, SpaceX says it has resolved a valve problem that kept one of its Falcon 9 boosters from successfully touching down on a barge in the Atlantic Ocean in April, ahead of another landing attempt after a launch from Cape Canaveral set for Sunday.

Watch live views from the Kennedy Space Center’s launch pad 39A as SpaceX prepares for the first flight of the Block 5 Falcon 9 rocket. The rocket is scheduled to launch the Bangabandhu 1 communications satellite no earlier than 10 May.