SpaceX launched its Falcon 9 rocket from Kennedy Space Center this morning at 3:27AM ET, NASA announced today. The rocket pushed four astronauts on NASA’s Crew-7 mission into orbit before a scheduled Sunday morning dock with the International Space Station (ISS).

The mission brings astronauts from four countries to the ISS — Jasmin Moghbeli of NASA, the European Space Agency’s Andreas Mogensen, Japan Aerospace Exploration Agency astronaut Satoshi Furakawa, and Konstantin Borisov, a Russian cosmonaut. When the Dragon spacecraft — named Endurance — autonomously docks with the ISS, it will bring the station’s crew number up to 11 for a few days until board the capsule and return to Earth in a few days.

“Aboard station,” says NASA Administrator Bill Nelson, “the crew will conduct more than 200 science experiments and technology demonstrations to prepare for missions to the Moon, Mars, and beyond, all while benefitting humanity on Earth.”

The launch was previously scheduled for Friday but NASA announced Friday it was pushed back so mission managers could confirm environmental control and life support systems were properly functioning. The mission was already delayed multiple times, including on two occasions to make way for a separate mission to send up the massive Jupiter 3 communications satellite.