 His interest in stratospheric flight was also shared by Marshal Mikhail Tukhachevsky who supported this early work.After a long series of unmanned tests of vehicles, Korolev's RP-318-1 rocket aircraft flew on 28 Feb 1940.That Spring, TsAGI ("ЦАГИ – Центра́льный аэрогидродинами́ческий институ́т – Tsentralniy Aerogidrodinamicheskiy Institut" Central Aerohydrodynamic Institute) hosted a conference for aircraft chief designers on the subject of ramjet and rocket propulsion.