It has been 23 years since the Challenger exploded on take off reminding us all that space travel was then, and is still dangerous. It has happened since, and as we continue to expand into space it will certainly happen again but at least for me it will never be burned into my memory the way that the challenger was.
I would have been about 9 when it happened. I don't remember where I first saw it, but I don't believe that it was in school as so many others, but I know that it struck me especially hard that there was a teacher on the flight. I have been lucky and always had good teachers and the idea that someone like one of them could have died meant more to me than the astronauts.
Even then though, I understood that we had to continue. It isn't just a love for science and science fiction which convinces me that we must continue but a love for mankind.
As a species we have survived because of our ability to expand and adapt. While so many other species of animals on this planet have been rendered extinct we have flourished because there isn't a place we can't survive, but we are still at risk, just as the dinosaurs were likely destroyed by an asteroid our global civilization is at risk. The only way that we as a species can ensure our survival is to continue what has worked in the past. We must expand into the rest of our solar system and adapt to live there or adapt it to support us.
Let us remember the Challenger not because of how the people on that ship died but because of how they lived. We, like those on the shuttle, are explorers and we must continue to be so.