http://www.wishuponastarproject.co.uk/

Long time lurker here, forgive the intrusion. This is an astronomy-based exchange project with schools in India. Your pupils can compete to win a trip to Kennedy Space Centre and also be published in the book that the University of Central Lancashire will publish from this.

This is expected to generate over 9000 entrants and based on the last book, Letters to Africa, should sell over a thousand copies so this will be great for your school to get stuck in to. Participation is free. Contact me if you're interested.