It's likely a misspelling of one of the following:

* Astronomical: Relating to astronomy, the study of celestial objects.

* Astronautical: Relating to the science and technology of space travel.

* Astronomical: Immensely large or great in size, scope, or degree (e.g., "astronomical costs").

If you can provide more context about where you saw this word, I might be able to give you a more specific answer.