Columbia in flight

Editors' note: This slideshow initially ran on April 11, 2010. We are rerunning it today, a year later, to mark the 30th anniversary of Columbia's debut flight.

After the first few, anniversaries typically get the most attention in increments of 5 or 10--the 10th, the 20th, the 25th, and so on. But this month, it's a 29th anniversary that stands out, and for bittersweet reasons. It was in April 1981 that NASA carried out the first-ever orbital flight of the space shuttle. And as things stand now, NASA's small fleet of shuttles will be retired after a final mission in September of this year.

This image shows that first orbiter, the Columbia, on its return flight to Earth with its two-man crew on April 14, 1981, headed toward the dry lake bed at Edwards Air Force Base in California. The shuttle's dimensions: 122 feet long and 57 feet high, with a wingspan of 78 feet.