. "Liberty was a 2011 launch vehicle concept proposed by Alliant Techsystems (ATK) and Astrium for phase 2 of the NASA Commercial Crew Development (CCDev) program intended to stimulate development of privately operated crew vehicles to low Earth orbit.Similar to the defunct Ares I project, which consisted of a five segment Space Shuttle Solid Rocket Booster (SRB) and a new cryogenic second stage, Liberty would combine a five-segment SRB with the core stage of the European Ariane 5 as a second stage. "@en . "90.0"^^ . . . . "Liberty"@en . . . "2"^^ . "5.4"^^ .