Frankly, I find it fairly "unenlightened" for a person to go around
pretending that rituals in memory of the dead have no useful purpose
for humanity.

Maybe we can all hold hands around the spacecraft and have a sun dance to
keep the rain gods away to assure good weather for the launch.
OOGIDABOOGIDA!

Really, firing ashes into the sky isn't going to do a thing for humanity.
Using the space for a time capsule might though.