  Based on our Chandra imaging-spectroscopic observations, we present the
latest evolution of the X-ray remnant of SN 1987A. Recent changes in the
electron temperatures and volume emission measures suggest that the blast wave
in SN 1987A is moving out of the dense inner ring structure, also called the
equatorial ring (ER). The 0.5-2.0 keV X-ray light curve shows a linearly
declining trend (by $\sim$4.5 % yr$^{-1}$) between 2016 and 2020, as the blast
wave heats the hitherto unknown circumstellar medium (CSM) outside the ER.
While the peak X-ray emission in the latest 0.3-8.0 keV image is still within
the ER, the radial expansion rate in the 3.0-8.0 keV images suggests an
increasing contribution of the X-ray emission from less dense CSM since 2012,
at least partly from beyond the ER. It is remarkable that, since 2020, the
declining soft X-ray flux has stabilized around $\sim$7 $\times$ 10$^{-12}$ erg
s$^{-1}$ cm$^{-2}$, which may signal a contribution from the reverse-shocked
outer layers of ejecta as predicted by the 3-D magneto-hydrodynamic (MHD)
models. In the latest ACIS spectrum of supernova remnant (SNR) 1987A in 2022 we
report a significant detection of the Fe K line at $\sim$6.7 keV, which may be
due to changing thermal conditions of the X-ray emitting CSM and/or the onset
of reverse shock interactions with the Fe-ejecta.
