I remember each of these accidents well and the aftermath that ensued. Each had a root cause in human error that led to a chain of circumstances that directly caused each accident.
As America prepares to return to manned spaceflight in the next few years the lessons learned from the loss of these crews must be remembered by NASA, SpaceX, Boeing, Virgin Galactic, and all who would fly humans into space.
There will be more losses in space as we fly new missions to places we have never been before and for durations that will push technology and crews. Humanity has to keep pushing the boundaries of space exploration for the benefit of the planet and our species. If we don't, we will become extinct.
Godspeed Apollo 1, Challenger and Columbia - you are NEVER forgotten and we see you in the stars that beckon us.
Sky Guy in VA