Ariane 3 European launcher strap-on booster development, qualification and flight

Ariane 3 is an improved version of the European Ariane launcher System obtained by adding two solid propellant Strap-on boosters. This modification increases the payload from 2175 Kg placed into geostationary transfer orbit. The Strap-on booster, loaded with 7,3 metric tons of solid propellant each and providing a maximum thrust of 730 KN, has been developed and qualified at SNIA BPD, Defence and Space Division, Colleferro, Italy. The program started in late 1979 and the first flight of the new Ariane 3 version took place successfully on 4 August 1984. This paper presents the configuration of the motor and describes the main steps of the design, development and qualification program. The first flight data are then compared with the qualification data.