9/11 Anniversary: NASA Shares Images of That Day Taken by US Astronaut on ISS

The agency noted that the September 11th attacks are considered a national catastrophe in the US that resulted in a "staggering loss of life" and, importantly, a profound shift in American culture. On that dark September Tuesday, aboard the ISS was the only American astronaut to capture the moment that, some say, could define the 21st century.