Would those same teenagers also not know that the ISS exists or that humans went to the moon 50 years ago?

What kind of odd question is that?

If, as your tone implies, you believe that every teenager knows everything and it's not possible for some of them to have not heard or these things, then you must in fact be a teenager yourself.

I don't think it's unreasonable to be surprised that a teenager (at least, an American teenager) isn't aware of such a thing. They've managed to get through school without once being shown a photo of the space shuttle? Not one blurb? Never seen it in a TV commercial? Photograph?

It was certainly never mentioned when I was in school. I knew about it, but I bet some of my classmates didn't. And it hadn't even been retired yet.

Challenger was mentioned, but only because I brought in a newspaper clipping for the 20th anniversary.

Try asking random strangers what stars are, and which is farther away, the stars or the moon.

Prepare to be disillusioned about humanity.