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SMC X-1 has exhibited three super-orbital period excursions since the onsetof X-ray monitoring beginning with RXTE's launch in 1995. NICER has recentlyprobed a fourth observed excursion beginning in 2021 with our programMonitoring Observations of SMC X-1's Excursions (MOOSE). These sensitive newMOOSE data probe different super-orbital periods and phases within them.Spectral fits to the high-state continuum during April 2021 to January 2022show that the intrinsic spectral shapes are characterised by a soft (kT~0.19keV) disc component and a hard (Gamma~0.7) power-law tail. When the 2021-2022NICER observations, taken during an excursion, are compared to 2016 XMM-Newtonobservations (outside of an excursion), we find little evidence for intrinsicspectral variability across the high-states, but find evidence for a >3 sigmachange in the absorption, although we caution that there may be calibrationdifferences between the two instruments. Thus, over different lengths ofsuper-orbital periods, we see little evidence for intrinsic spectral changes inthe high-state. Upcoming studies of the pulse profiles may shed light on themechanism behind the excursions.

Monitoring Observations of SMC X-1's Excursions (MOOSE) I: Program Description and Initial High-State Spectral Results