From a New York Times story by Michael Roston headlined “Space and Astronomy in February: What to Expect”:

February’s space events start with a somber memorial.

The first of the month is the 20th anniversary of the Columbia disaster, when seven astronauts died as their space shuttle broke up during a return flight to Earth after 17 days in space. The cause of the accident was insulating foam that fell off the shuttle’s external fuel tank during its ascent to space. The foam struck the shuttle’s left wing and damaged its heat shielding, which then failed 16 days later during atmospheric re-entry.