Pegasus rocket launches from underside of plane
Eight satellites, each the size of a small suitcase, have blasted off over Cape Canaveral on a rocket launched from the underside of a plane.
It was the third launch attempt by Nasa.
It is hoped the satellites will measure wind speeds in stormy weather.
Current satellites can not measure accurately when it is raining heavily, so forecasters have to rely on "Hurricane Hunter" planes.
Footage courtesy of Nasa TV.