re proton centaur in article r aii ivs access digex net prb access pat writes in article apr zeus calpoly edu jgreen trumpet calpoly edu james thomas green writes has anyone looked into the possiblity of a proton centaur combo i don t know a whole lot on proton but given that it is a multi stage rocket up to stages it may not really need the centaur plus it may end up seriously beating on said centaur the proton has been used in and stage versions the two stage version was used for the first launches while the and stage versions are used today the four stage version is used mostly for escape and geosynchronous orbits while the stage version is used for low earth orbits since this is the version that launched mir and the salyuts and the add on modules for mir as long as centaur is smaller than mir which i believe it is it should fit under the shroud i vaguely recall that the russians are developing a lh lox upper stage for the proton chris jones clj ksr com
