The Ares I CLV (Crew launch vehicle) is a heavy launch vehicle design for carrying the CEV into LEO. Its first stage is a five segment SRB, like those used for the Ares V, creating up to 16 MN thrust at liftoff. The second stage is currently under development and will be a cryogen stage with two J-2X engines.
It consists of two and a half stages, two five segment SRBs with a cryogenic sustainer stage and a cryogenic second stage. The sustainer stage uses five expendable RS-68 rocket engines, while the second stage uses a single J-2X. It will most likely launch from a modified LC 39 from KSC.
See also: Exploration Systems Architecture Study