  In this white paper, we discuss future uses of the LSST facility after the
planned 10-year survey is complete. We expect the LSST survey to profoundly
affect the scientific landscape over the next ten years, and it is likely that
unexpected discoveries may drive its future scientific program. We discuss
various operations and instrument options that could be considered for an
extended LSST mission beyond ten years.

Instrumentation and Methods for Astrophysics