The Monday golf ball-size hail fell making a ring of thousands of dings on the upper reaches of the 153-foot-tall external tank. It crushed some foam along wedge-shaped brackets, an area where foam has been known to shed in the past. The hail also caused cosmetic damage to more than two dozen tiles along the shuttle's left wing.
Atlantis will now have to launch after a Russian Soyuz vehicle completes a mission to the international space station in the first part of April, putting the next opportunity likely between late April and late May, according to various reports. April 22nd was mentioned as a new target.
During their 11 days in space, Atlantis' astronauts are scheduled to deliver a 35,000-pound addition to the international space station, the heaviest ever, along with a new pair of solar arrays. Crew members are tasked with unfurling the solar arrays, folding up an old pair, and conducting at least three spacewalks.