  In the study of hot and dense nuclear matter, created in relativistic
heavy-ion collisions, dilepton measurements play an essential role. Leptons,
when compared to hadrons, have only little interaction with the strongly
interacting system. Thus, dileptons provide ideal penetrating probes that allow
the study of such a system throughout its space-time evolution. In the low mass
range ($M_{ll}<1.1$ GeV/$c^2$), the dominant source of dileptons originates
from the decay of vector mesons which may see effects from chiral symmetry
restoration. In the intermediate mass range ($1.1<M_{ll}<3.0 $ GeV/$c^2$), the
main contributions to the mass spectrum are expected to originate from the
thermal radiation of a quark-gluon plasma as well as the decays of charm
mesons. In the high mass range ($M_{ll}>3.0$ GeV/$c^2$), dilepton measurements
are expected to see contributions from primordial processes involving heavy
quarks, and Drell-Yan production.
  With the introduction of the Time-of-Flight detector, the STAR detector has
been able to perform large acceptance, high purity electron identification. In
this contribution, we will present STAR's recent dielectron measurements in the
low and intermediate mass range for RHIC beam energies ranging between 19.6 and
200 GeV. Compared to electrons, muon measurements have the advantage of reduced
bremsstrahlung radiation in the surrounding detector materials. With the
upcoming detector upgrades, specifically the muon detector (MTD), STAR will be
able to include such measurements in its (di-)lepton studies. We will discuss
the future dilepton program at STAR and the physics cases for these upgrades.
