Falcon 9

SpaceX test-fired a Falcon 9 rocket at NASA’s Kennedy Space Center early Thursday, checking off another box on the pre-flight checklist before liftoff Sunday with a four-person crew heading for the International Space Station. But a weather forecast shows a high risk that winds or waves int the Atlantic Ocean could force a launch delay.

Matthias Maurer’s last name in German means brick layer. Naturally, Maurer says, that means he has been assigned to perform an experiment with concrete during his six-month stint on the International Space Station.

NASA and SpaceX managers have given a ‘go’ for the launch of four astronauts aboard a Crew Dragon to the space station at 9:03 p.m. EST Wednesday (0203 GMT Thursday).

The four astronauts set to blast off Oct. 30 to the International Space Station visited Cape Canaveral over the weekend for a test run inside SpaceX’s new Crew Dragon Endurance spacecraft, one of the last training events before they return to Florida on launch week.

The astronauts who will ride SpaceX’s newest Dragon spaceship into orbit later this month said Thursday they named their spacecraft “Endurance” as a tribute to the human spirit and a historic sailing vessel used by Antarctic explorer Ernest Shackleton.