WP_enqueue_script inside shortcode?

I’ve got shortcode that needs to include JS library only once and only there where it’s used.

function shortcode_function($atts, $content = null) {
    $class = shortcode_atts( array('something' => '0'), $atts );

    return "<script src=\"http://maps.googleapis.com/maps/api/js?sensor=false\"></script> 
            And here goes HTML code for the map.";
}
add_shortcode("sh", "shortcode_function");

The problem is that above example is going to include library several times if maps shortcode is used several times. How can I prevent that? Or more precisely: how can I do it “the correct way”? Can I use wp_enqueue_script() in that place?

Just one requirement: I really need this to include that library only-when-shortcode-is-used.

Yes, you should use wp_enqueue_script(). The script will be loaded in the footer (action: wp_footer()). Just once.

To inspect the order of available hooks, functions etc. per request try my plugin T5 WP Load Order.