It was morally wrong. Christians used to pray to God that He would spare them an “unprovided” death, an unforeseen death. They prayed that because they wanted the opportunity to prepare for death.
Maybe none of the astronauts were believers. But somehow I rather doubt it.
Even ancient pagan philosophers understood that, because we are not mere animals, preparing for death is the mark of a human being. Not everyone gets the opportunity to do so, which is why Christian teachers always advised people to “see ahead” to death at all points in life (memento mori).
I would think that even secular folk, if they think about it, would appreciate the opportunity to prepare for death.
But whaddah I know.
I hope I am able to say this when my time comes.
“I have fought a good fight, I have finished the course, I have kept the faith.
Henceforth there is laid up for me a crown of righteousness, which the Lord, the righteous judge, shall give me at that day: and not to me only, but unto all them also that love his appearing.