Today, we hold our Day of Remembrance to honor all of our fallen heroes, including the crews of Apollo 1, Challenger STS-51L, and Columbia STS-107, as well as all of our NASA colleagues who lost their lives while furthering the cause of exploration and discovery. Feb. 1, 2023, marks 20 years since the Columbia tragedy. As we return to the Moon and prepare to venture onto Mars, it is vital that we always adhere to our first core value of safety. Our constant attention to safety is the cornerstone upon which we build mission success—we work to never repeat the mistakes of our past. In the comments, we invite you to share how their legacies inspire you, and if you experienced these dark days with us, to share your memories. Image description 1: The Columbia crew pose together in their orange flight suits during their official portrait. From left, the crew included David Brown, Rick D. Husband, Laurel Blair Sutton Clark, Kalpana Chawla, Michael P. Anderson, William C. McCool and Ilan Ra...