SAN JUAN, Puerto Rico (AP) - As NASA secured Kennedy Space Center on Thursday for potentially catastrophic wind and rain, the private SpaceX company squeezed out a rocket launch.

Kennedy is closing its doors to all nonessential staff, effective Friday. Of 9,000 workers, a hurricane crew of 120 people will ride out Irma on site.

Most critical buildings can withstand gusts up to about 135 mph (217 kph), but Irma's winds could well exceed that if the storm's center reaches Cape Canaveral.

Space center workers rushed to stack sandbags at doorways and cover the Orion capsule scheduled to launch in two years on a brand new NASA rocket.

Meanwhile, SpaceX managed to launch an unmanned Falcon rocket carrying an Air Force minishuttle bound for a long experimental flight in orbit.