I'm presuming that the OP's parents know her well enough to know whether she wants to be buried or scattered or sent into space. After all, that's kind of one of those things you're going to need to tell someone about ahead of time if you want it done.
Why would you presume that? My parents don't have a clue what I want. It's just not the type of thing we talk about.
I suppose that I presumed the same thing: that if the parents bought it for them, that they already had some idea of the OP's wishes.
My parents (dad, for some reason) are so tickled with theirs that we all drive by and visit it when we go to visit them. Seriously
To the rest of us, it's funny and it was a good thing because it opened up a discussion of what my wishes are.
While this gift seems impractical for me because DH & I desire cremation, I have to admit that I've been wondering what to do with my ashes. I could just make that my next-of-kin's problem. My desire is cremation and then for my next-of-kin to spread the ashes wherever has the greatest meaning for him (or them, whoever). However, it has recently come to my attention that the state I live in has laws about the disposition of ashes. I do not want to be in an urn, carted around, but when I'm dead I won't be around to be all snitty about it.
A gift like what was given to the OP would eliminate that concern.
At any rate, the suggested 'thank-you's' given by Elisabunny and others - even tongue-in-cheek - are excellent!