French CNES official describes Ariane V launcher

The need for a new and larger version of the ESA Ariane-4 launch vehicle is examined, taking the present situation and future trends in the LEO, SSO, and GTO markets into account; the principal characteristics required of a future launcher are discussed (payload mass and dimensions, reliability, safety, and potential for furhter development); and the three proposed A-5 configurations are characterized and illustrated with drawings. The A-5R is based on the A-44L, replacing its second stage with one using the HM60 large cryogenic engine being developed by ESA. The A-5C employs four HM60s in its first stage and one HM60 in its (optional) second stage, while the A-5P has one single-HM60 stage and two 150-tonne solid-propellant boosters. The technical and economic factors to be weighed in choosing one of these configurations are considered.