  The black hole binary Cygnus X-1 was observed in late-2012 with the Nuclear
Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage
over the ~1-300 keV range. The source was in the soft state with a
multi-temperature blackbody, power-law, and reflection components along with
absorption from highly ionized material in the system. The high throughput of
NuSTAR allows for a very high quality measurement of the complex iron line
region as well as the rest of the reflection component. The iron line is
clearly broadened and is well-described by a relativistic blurring model,
providing an opportunity to constrain the black hole spin. Although the spin
constraint depends somewhat on which continuum model is used, we obtain a*>0.83
for all models that provide a good description of the spectrum. However, none
of our spectral fits give a disk inclination that is consistent with the most
recently reported binary values for Cyg X-1. This may indicate that there is a
>13 degree misalignment between the orbital plane and the inner accretion disk
(i.e., a warped accretion disk) or that there is missing physics in the
spectral models.
