Live coverage: Ariane 5 rocket launches TV broadcast satellites

NASA fired up four hydrogen-fueled main engines on the core stage of the first Space Launch System heavy-lift rocket Thursday in on a test stand in Mississippi, a redo of a crucial hot fire test that was cut short in January by technical issues. The engines burned more than eight minutes in an apparently successful test.

A commercial Cygnus resupply ship named for Robert H. Lawrence, Jr. — the first African American selected as an astronaut — is awaiting liftoff Sunday evening from NASA’s Wallops Flight Facility on Virginia’s Eastern Shore to begin a 35-hour trip to the International Space Station.

A compact exoplanet observatory built in Europe to help astronomers determine the sizes of distant worlds around other stars is scheduled for launch Wednesday from French Guiana aboard a Soyuz rocket.