Hurricane Irene gathers strength as it passes over the Caribbean on Aug. 22 in this photo snapped by astronaut Ron Garan high above the Earth while aboard the International Space Station.

 

Irene is expected to slam the East Coast of the U.S. this weekend and mandatory evacuations have been issued for some coastal counties for the storm, which NOAA is saying could be "extremely destructive with massive disruptions to society and commerce along its entire track."