Today Marks NASA's Day of Remembrance at Arlington National Cemetery

President Obama and NASA Administrator Charles Bolden conducted a wreath-laying ceremony at Arlington National Cemetery on Friday to honor the men and women who were lost in space tragedies. The NASA memorial day acknowledged and celebrated the lives of victims lost in the three spaceflight disasters.

This annual day of reflection recalls the accidents of the Apollo 1 Fire in 1967, the Challenger space shuttle accident of 1986 and the Columbia shuttle tragedy in 2003. Oddly enough, the anniversaries of these three disasters fall within a week of each other.

"On this Day of Remembrance, we join the American people in honoring the men and women of NASA who have given their lives in our nation's space program," Obama said in a statement in this NBC News article. "Our exploration of space has expanded our knowledge of the universe, improved our lives here on Earth and been a source of inspiration and pride for generations of Americans."

Here's a link to NASA's Day of Remembrance website if you would like to particpate in the day of remembrance.

NASA Administrator Charles Bolden mirrored Obama's statements and gave his condolences to the men and women that dedicated their lives to space exploration, citing their commitment and endless pursuit.

A total of 17 were remembered in today's service. The Apollo 1 fire occurred on January 27^th, 1967, claiming three victims in a fire during a dress rehearsal. The Challenger disaster killed seven in what is known as the most infamous space accident, occurring on January 28^th, 1986. Within 73 seconds after liftoff, the Challenger exploded in mid-air and took the lives of everyone on board. Lastly, the Columbia accident took seven lives as well. On February 1^st, 2003, the space shuttle broke apart during re-entry at the conclusion of a marathon science mission in orbit.

To read more about the memorial service, visit this NBC News article.