Knock and await call before entering.
A man sits behind the desk, pouring over papers and articles, books are put neatly away, save for the one he is also using. Floating above him is a miniature planetary system that was left as a gift from last term in the observatory.
The shelves are filled with books and photos either in space, from space, or of space, and there's a picture of a group of people on a shuttle mission...one looks shockingly like a younger version of the man behind the desk.