I used to etheric project out into space all the time, and even went close to the moon once (close, but not close enough). The minute I decided I wanted to go there, that was it. No more space travel, except for remote viewing. It's frustrating- but I think it has to do with development (in your case). Your understanding leads me to believe that you have evolved past the etheric projection as the first step to projection (I'm not sure if you know what I mean) so I would suggest 'backing into it'- astral project to the moon, and then step down into an etheric projection 'there'- I'd suggest asking for help, and also asking if it's the right way to do it. In fact, I think I'll take my own advice and try it.