  Relativistic positioning systems are interesting {\em technical objects} for
applications around the Earth and in the Solar system. But above all else, they
are basic {\em scientific objects} allowing developing relativity from its own
concepts. Some past and future features of relativistic positioning systems,
with special attention to the developments that they suggest for an {\em
epistemic relativity} (relativistic experimental approach to physics), are
analyzed. This includes {\em relativistic stereometry}, which, together with
relativistic positioning systems, allows to introduce the general relativistic
notion of (finite) {\em laboratory} (space-time region able to perform
experiments of finite size).
