In addition to the Observatory, what is today ONERA, a national aerospace research institute and wind tunnel has been present since the military opened its aerostatic (lighter-than-air) field in the Chalais park in 1877.
Selain Observatorium, juga terdapat ONERA, sebuah institut penelitian nasional terhadap penerbangan (dan terowongan angin), telah didirikan sejak militer membuka lapangan udara statis (lebih ringan dari udara) di taman Chalais tahun 1877.