Uranophobia or Ouranophobia
Urano is Greek (meaning heave) and phobia is Greek (meaning fear). So people with this phobia will fear Heaven or the sky. As Christians we shouldn’t fear Heaven, as when we die, that will be where we will be present with the Lord.
Not only is this the fear of Heaven, but also the fear of the sky. They might fear the sky is falling or being up in the sky, say maybe airplane, helicopter, etc. But, as stated it is also the fear of Heaven.