It is impossible but it is possible through imagination, there is no limitation when it comes to the time to imagine something. Every human-made born with the ability to think, imagine and express what he/she think/imagine in any form.
I was imagining sketching the tower and during the time am sketching it another idea comes to mind about adding clouds below it and to make as if it was above the sky.
Thes below are steps that I passed through sketching this Flying Tower;
Thanks for taking your time to view my art and I hope you like it.