SpaceX aimed to launch its third crew a little before sunrise Friday, this time using a recycled capsule and rocket.

The four astronauts, representing the U.S., Japan and France, were supposed to fly to the International Space Station on Thursday. But liftoff was delayed because of poor weather offshore.

SpaceX's Dragon capsule requires calm waves and winds in case an emergency splashdown is needed during the climb to orbit. Friday's forecast should be much improved, officials said. Liftoff was set for 5:49 a.m. EDT.

"Our friends on the @Space_Station are expecting us to show up and we don't want to be late," tweeted French astronaut Thomas Pesquet. "They even installed my bedroom recently and literally made my bed. Such nice hosts!"

For the first time, Elon Musk's company is launching astronauts with a previously flown capsule and rocket, just as it's done for station supply runs. This crew capsule launched with SpaceX's first crew last May, and the rocket hoisted the second crew in November.

NASA's spacecraft commander Shane Kimbrough and his crew will spend six months at the space station, replacing four astronauts who will return next Wednesday in their own SpaceX capsule, parachuting into the Gulf of Mexico near Tallahassee, Florida.

To celebrate Earth Day on Thursday, Kimbrough tweeted a sunrise beach shot from NASA's Kennedy Space Center.

"Amazing way to appreciate our planet this morning!" he said.

Besides Kimbrough and Pesquet, the crew includes NASA's Megan McArthur and Japan's Akihiko Hoshide.