Falcon Heavy hot fire as seen from Kennedy Space Center Press Site

A senior NASA official said Tuesday that the Space Launch System, a huge heavy-lift rocket years behind schedule, could launch astronauts on a moon landing mission in 2024 on just its third flight to meet a goal announced last month by Vice President Mike Pence, while commercial companies will be entrusted with more responsibility to develop a lunar lander and a modest mini-space station, or Gateway, in lunar orbit.

Nine Merlin main engines at the base of a SpaceX Falcon 9 rocket fired at launch pad 39A Saturday, passing a major test before the company’s next launch, a secretive mission slated for liftoff Wednesday night.

A Soyuz rocket took off from French Guiana on Thursday with the SES 15 communications satellite, a craft heading for an orbit more than 22,000 miles over the equator to provide airborne wifi and aeronautical navigation services over the United States.