PEGASE is a design for a space observatory developed by France in the early 2000s. [1] It combined formation flying with infrared telescopes operating as a double-aperture interferometer. [1] Three free-flying satellites would operate together;a beam combiner and two siderostats. [1] The baseline of the interferometer would be adjustable to between 50 and 500 meters. [1] The goal of the mission is the study of Hot Jupiters ("pegasids"), brown dwarfs and the interior of protoplanetary disks. [2] The design was developed by Centre National d'Études Spatiales and was studied for a launch as early as 2010–2012. [3] However, the Phase-0 part of the study in 2005 suggested it would take 8 or 9 years to develop. [1]