  Debris disks are exoplanetary systems containing planets, minor bodies (such
as asteroids and comets) and debris dust. Unseen planets are presumed to
perturb the minor bodies into crossing orbits, generating small dust grains
that are detected via remote sensing. Debris disks have been discovered around
main sequence stars of a variety of ages (from 10 Myr to several Gyr) and
stellar spectral types (from early A-type to M-type stars). As a result, they
serve as excellent laboratories for understanding whether the architecture and
the evolution of our Solar System is common or rare. This white paper addresses
two outstanding questions in debris disk science: (1) Are debris disk minor
bodies similar to asteroids and comets in our Solar System? (2) Do planets
separate circumstellar material into distinct reservoirs and/or mix material
during planet migration? We anticipate that SOFIA/HIRMES, JWST, and WFIRST/CGI
will greatly improve our understanding of debris disk composition, enabling the
astronomical community to answer these questions. However, we note that despite
their observational power, these facilities will not provide large numbers of
detections or detailed characterization of cold ices and silicates in the Trans
Neptunian zone. Origins Space Telescope is needed to revolutionize our
understanding of the bulk composition and mixing in exoplanetary systems.
