  On two occasions, we obtained nearly simultaneous ~ 4 kilosecond snapshot
observations of the Galactic black hole and microquasar XTE J1550-564 with
Chandra and RXTE near the peak of its May, 2000 outburst. The low-energy
sensitivity of Chandra and the resolution of the High Energy Transmission
Grating Spectrometer (HETGS), coupled with the broad energy range and large
collecting area of RXTE, have allowed us to place constraints on the outburst
accretion flow geometry of this source in the ``intermediate'' X-ray state. The
0.65-25.0 keV continuum spectra are well-described by relatively hot (kT ~ 0.8
keV) accretion disk and hard (Gamma ~ 2.3) coronal power-law components. Broad,
relatively strong Fe K-alpha emission line (EW ~170 eV) and smeared absorption
edge components consistent with Fe XXV are strongly required in joint spectral
fits. The resolution of the Chandra/HETGS reveals that the broad Fe K-alpha
emission lines seen clearly in the individual RXTE spectra are not due to an
intrinsically narrow line.
