Is the Navigo Découverte card available to purchase at the Orly airport

Navigo Découverte is available for purchase at Orly airport from the Orlybus station ticket office.  You'll have to follow the signs throughout Orly airport for the Orlybus stations.
 
I believe the reason why the Navigo pass is sold at the Orlybus station and not the Orlyval station is because Navigo is valid for Orlybus, but not the Orlyval train.