  FUV spectra of Eta Car, recorded across two decades with HST/STIS, document
multiple changes in resonant lines caused by dissipating extinction in our line
of sight. The FUV flux has increased nearly ten-fold which has led to increased
ionization of the multiple shells within the Homunculus and photo-destruction
of molecular hydrogen. Comparison of observed resonant line profiles with
CMFGEN model profiles allows separation of wind-wind collision and shell
absorptions from the primary wind, P Cygni profiles.The dissipating occulter
preferentially obscured the central binary and interacting winds relative to
the very extended primary wind. We are now able to monitor changes in the
colliding winds with orbital phase. High velocity transient absorptions
occurred across the most recent periastron passage, indicating acceleration of
the primary wind by the secondary wind which leads to a downstream, high
velocity bowshock that is newly generated every orbital period. There is no
evidence of changes in the properties of the binary winds.

Solar and Stellar Astrophysics