We can praise their profound courage - which is demonstrated and unquestionable. Anyone who reflects on their own personal frailty amid the forces of nature - especially the unfamiliar and unforgiving realm of space flight - can see that.
We can admire their curiosity and intellect, especially the commitment to cooperate in conquering the unknown with knowledge instead of weapons.
We can respect the personal striving and the sense of enterprise that pushed each of these pioneers to this final distinction in their life's work.
But what we may appreciate most at this moment is their humanity: They were our children, our mothers and fathers, our sisters and brothers, who linked hands from diverse reaches of the earth to embark together on this fateful voyage. Each one entrusted their personal spark of life to a common purpose for the advancement and opportunity of all who will live in the future, as long as mankind shall walk the earth and swim in the sea of stars.