He is referred to as being one of the founders of modern rocketry and astronautics, along with the Russian Konstantin Tsiolkovsky, the Germans Hermann Oberth, Wernher von Braun and the American Robert H.Esnault-Pelterie developed and manufactured aeroplanes and aero engines under the name REP. His first experiments in aviation were based on the Wright brothers 1902 glider.[5] After condemning the Wright brothers' approach, he developed the concept of the aileron, fitting a pair of mid-gap control surfaces in front of the wings.This potentially "initial" example of the use of ailerons of any sort is believed to pre-date all others,[6] after their patent description in 1868 by British inventor M. P. W. Boulton was approved in that year.After a modified version of this plane was flown for the last time in 1909 at Rheims, Pelterie stopped flying and instead focused on the development and manufacture of aircraft.[9][10] He became interested in space travel, and, not knowing of Tsiolkovsky's 1903 work, in 1913 produced a paper that presented the rocket equation and calculated the energies required to reach the Moon and nearby planets.On 8 June 1927 Esnault-Pelterie gave a symposium for the Société astronomique de France (French Astronomical Society) titled L'exploration par fusées de la très haute atmosphère et la possibilité des voyages interplanétaires, concerning the exploration of outer space using rocket propulsion.The Prix REP-Hirsch was an international award of the Société astronomique de France given in recognition of the study of interplanetary travel and astronautics.In addition to Esnault-Pelterie, Hirsch, and Rosny the elder, it included General Gustave-Auguste Ferrié (President), Jean Perrin and Eugène Fichot (Vice-Presidents) and other expert members.
Avion Esnault-Pelterie, 1908
The wing structure of the R.E.P Type D Monoplane, 1911.