Live coverage: Falcon 9 rocket launches, and lands, at Cape Canaveral

NASA has extended development agreements with SpaceX and Sierra Nevada Corp. past a March 31 deadline, giving the companies more time to complete delayed tests on commercial spacecraft intended to one day ferry astronauts into space.

Astronauts will not fly to the International Space Station on SpaceX’s Crew Dragon spaceship until at least May 2018, NASA said this week, missing a previous target launch date at the end of next year.

SpaceX is set to retire its current fleet of Dragon capsules, in use since 2010, next year and begin flying supplies to the International Space Station on a new variant of the Dragon spacecraft based on the model in development to carry astronauts.