Since the 1970’s, Snecma Propulsion Solide has been developing equipment, parts and systems for the Ariane launcher nozzle throats for the various versions of the Viking motor that powered the Ariane 1 to Ariane 4 launchers, constant-pressure control units for the 1st and 2nd stages and for the liquid booster for Ariane 4, titanium spheres for the 2nd stage, igniters and starters for the HM7 motor, sensors etc.These Solid Rocket Motors only operate for the first 2 minutes of flight, but in that time must provide sufficient thrust (90% of the rocket’s total thrust) to release the rocket from the dense lower layers of the atmosphere. Europropulsion (a subsidiary of the SAFRAN Group and AVIO) is responsible for the development and production of these rockets. Ariane 5 can now place satellites of up to 10 metric tons into geostationary transfer orbits.
These boosters must offer extremely high levels of reliability under harsh operating conditions – a requirement that has prompted the development of the largest carbon/carbon parts that have ever been produced, notably for the nozzle throat (inside Ø: 900 mm, outside Ø: 1300 mm, thickness: 80 mm). A continuous evaluation and review of the design of the SRM nozzles searches for ways to reduce costs and simplify the production of these parts.