Orsay campus is located at about 30 km south-west from Paris and is easily accessible from Paris, by the RER B, Orsay-Ville
Main directions :
From Roissy airport :
Take RER B towards Saint-Rémy Les Chevreuses and get out at Orsay-Ville.
From Paris downtown :
Metro-RER-Bus Transport itinerary is available under this link RATP-itenerary web site.
Transport fees and policy informations :
Please visit this link, you may find interesting options and prices with the NAVIGO pass
Note : For a NAVIGO pass, you will be charged extra 5 Euros for the card but it is valid at least 10 years. You need a photograph.
With the NAVIGO, you can use all transportation in Paris and suberb (bus, metro, RER in 5 zones, including the travel from the Airports except Orly-Val )
Other Transport informations are available under this link RATP web site.