NASA in the grip of Hurricane Earl

NASA was engaged in an unprecedented study of the latest weather threat to the American coast last night.

It sent scientists to ride the 145mph Hurricane Earl on a quest for the "holy grail" of storm research, as one million people on the ground trembled in its path.

Aircraft including an unmanned Global Hawk drone, were flying into, around and above the storm, firing lasers at it to measure wind speed and humidity, as part of the multi-million dollar GRIP mission."This is going to be a game-changing hurricane experiment," said Dr Ramesh Kakar of Nasa's science mission directorate.

"For the first time, scientists will be able to study these storms and the conditions that produce them for up to 20 hours straight. GRIP will provide a sustained, continuous look at hurricane behaviour at critical times during their evolution."

Hurricane Earl, pictured by satellite, right, was sprinting towards the east coast last night, prompting President Barack Obama to order officials to prepare for a "worst case" scenario. It has been classified as a category three storm; Hurricane Katrina was a category five. It is expected to hit the coast then move northward.

GRIP - the Genesis and Rapid Intensification Processes experiment - will put together a jigsaw of data on the storm as it develops.