Solaris is a sans serif or a grotesque as we still call it where I come from. (it is an old term which means strange compared with Roman which was the normal font) The face is an open sans, which means that the round signs take the air into the form, minuscule d is drawn kind of backwards like in Gill Sans, which sets off on minuskel a. Here is the Regular version, with a slightly difference between stems and hairlines.