Video: Liftoff of Atlas 5 rocket with Mexico’s Morelos 3

NASA Administrator Jim Bridenstine said this week the space agency is not unduly delaying the debut of new SpaceX and Boeing commercial crew capsules as engineers gear up for a challenging rapid-fire sequence of test flights in the next few months, all against the backdrop of in-depth safety reviews before clearing the privately-owned ships to carry astronauts.

Up to 24 launches are planned from Cape Canaveral in 2015, thanks to jam-packed manifests for SpaceX and United Launch Alliance to send up satellites for the U.S. military, NASA and commercial telecom operators.

A Northrop Grumman Antares rocket rolled out of its hangar Monday night, riding a self-propelled transporter for a mile-long trip to launch pad 0A on Wallops Island, Virginia, for a predawn liftoff Thursday with a Cygnus supply ship heading for the International Space Station.