Some people seem to unironically agree with this, so I'll say the obvious: I don't think the absence of a meaning to life has anything to do with the wastefulne

Some people seem to unironically agree with this, so I'll say the obvious: I don't think the absence of a meaning to life has anything to do with the wastefulness of sending your ashes into orbit. It's more wasteful than spreading them over the sea, for example. Unless you're actually saying that you don't believe in the concept of waste, which would be really sad for you and for everyone around you.