Let's make this birthday one to remember.

81 years old (Born on September 17, 1943)

Happy Birthday, Samuel T. Durrance! You've orbited the Earth more times than most of us have circled our neighborhood block—and your research on solar system origins has enlightened minds faster than NASA's rockets leave launch pads. With over 60 technical papers under your belt, you've officially written enough to fill a small spacecraft (or at least clutter up mission control).

From payload specialist extraordinaire aboard two Space Shuttle missions to unraveling cosmic mysteries about planetary evolution—your career is truly stellar! May this birthday be filled with laughter and joy that's out-of-this-world...and may gravity never weigh down your spirits or cake slices!