This question originally appeared on Quora, the best answer to any question. Ask a question, get a great answer. Learn from experts and get insider knowledge. You can follow Quora on Twitter, Facebook, and Google Plus.
I witnessed both of these disasters live but in very different contexts.
For Challenger, I was not yet an astronaut. I was still an aerospace engineer, working in the mission planning and analysis division. We were devising ways for space shuttles to approach and dock with some of the new (and quite varied) space station configurations (Power Tower, Delta, SOC, etc.). I was seated in a meeting—discussing various aspects of how to safely approach and dock while using minimal fuel—on the sixth floor of NASA Johnson Space Center's Building 1, the administration and management building, on launch morning.
We took a break from the meeting to turn our attention to the television set in the conference room. As the events unfolded, nominally at first, it quickly became clear to me that something had gone wrong. But we all sat there in silence. No one spoke; no one moved. It was not until I heard screams and sobs emanating from the hallway that reality truly sunk in. I walked back to the office, alone and deep in thought; the remainder of my day was not good.
The Columbia accident took on a far more personal signature. I was one of the family escorts for the mission, hand-picked by shuttle and mission commander Rick Husband.
I'm not sure exactly why he picked me, but I was honored. It would be the first and only time I was ever asked to be a family escort. I believe he gave me the "nod" because of my Christian faith—Rick was also a devout Christian leader—and my demonstrated successes while a not-yet-assigned astronaut.
As we fast-forward to landing day (all of this is covered thoroughly in my forthcoming book The Ordinary Spaceman: From Boyhood Dreams to Astronaut), I was hanging out at the crew family area, near the midpoint of runway 15/33 of the shuttle launch facility at Kennedy Space Center. It was an absolutely gorgeous day for a shuttle landing. Steve Lindsey, the lead escort and veteran space shuttle commander, and I were chatting with doctor and Columbia astronaut Laurel Clark's sister, enjoying the moment. As we watched the countdown clock intermittently and readied ourselves for what we thought was to be a wonderful landing and reunion, everything seemed to be progressing as planned. Of course, it didn't turn out that way.
The countdown clock continued to increase past 00:00. A security guard face's turned ghostly white in an instant. Capsule communicator/astronaut Charlie Hobaugh repeatedly called the Columbia crew with no response. Lindsey quietly uttered the words "Get ready," and I knew it was time—time to be strong in the face of true adversity.
It was the most difficult day of my life—even harder than when my father died, as that was what we were expecting. I do my best to describe the day's events in my book, but suffice it to say I felt a huge emptiness inside, and it is a burden I still carry today. That day changed me inside; it made me much more emotional than I can ever remember being. It tested my faith, and it still tests me.
But it never dulled my dream to fly in space. It only strengthened my resolve. We (NASA) would figure this out. We would make it safer than before. That's what we do. That's "how we roll."
Space flight is dangerous. Space flight is hard. We must keep that in mind as we move forward into the era of commercial spaceflight endeavors, lest we forget the lessons of our past.
Godspeed Challenger. Godspeed Columbia.
More questions on Quora: