Technical specifications
Performances
Burn time 130 s
Maximum pressure 60 bar (about 870 psi)
Maximum thrust in vacuum 6 700 kN (1,477,100 lb)
Initial thrust in vacuum 6 000 kN (1,323,000, lb)
Average thrust in a vacuum 900 kN (1,080,270 lb)
Specific impulse (ISVM) 270 s
Dimensions
Total weight 268 metric tons (590,800 lb)
Propellant weight 238 metric tons (524,700 lb)
Overall length 27 m (88.5 ft)
Casing diameter 3 m (9.8 ft)
Structural overview
The Ariane 5 launcher has two EAP boosters on either side of the central cryogenic body that generate more than 90% of the thrust during the first two minutes of flight. These Solid Rocket Motors (SRM) are 27 meters long and 3 meters in diameter. Due to their size and mass, almost 270 metric tons, they are divided up into three parts: a forward segment and two larger center and aft segments, each of which weighs 110 metric tons.
More information about Solid Rocket Motor (74,7 Ko)
Industrial organization
Europropulsion SA, an equally-owned subsidiary of Snecma (France) and Fiat Avio (Italy), is prime contractor for the SRM, with responsibility for development, production and technical coordination. It subcontracts realization of the main SRM subassemblies. Snecma Propulsion Solide produces the SRM nozzle in Bordeaux, and has subcontracted for development and production of the motor casing to MAN, a German company based in Augsburg. FiatAvio is in charge of the propellant grain, thermal insulation and igniter. The company’s Colleferro plant (Italy) installs the thermal insulation and manufactures the propellant for the forward segment and the igniter. Propellant for the center and aft segments is produced at the launch site in Kourou (French Guyana) by Regulus, a joint subsidiary of Fiat Avio and SNPE. Europropulsion is responsible for transporting subassemblies to the Booster Integration Building (BIP) in Kourou, where it assembles the SRM, and is responsible for all checkout operations. Europropulsion kicked off the manufacture of production SRM motors in June 1995. At the same time, it is playing an active role in various projects designed to increase the orbital payload capacity of Ariane 5, by undertaking complementary development initiatives that will decrease the weight of the SRM, while enhancing their ballistic performance. The development tests are performed on the BEAP vertical test rig, located near the launch zone in Kourou.