  Operating 1.5 million km from Earth at the Sun-Earth L2 Lagrange point, the
Origins Space Telescope equipped with a slightly modified version of its HERO
heterodyne instrument could function as a uniquely valuable node in a VLBI
network. The unprecedented angular resolution resulting from the combination of
Origins with existing ground-based millimeter/submillimeter telescope arrays
would increase the number of spatially resolvable black holes by a factor of a
million, permit the study of these black holes across all of cosmic history,
and enable new tests of general relativity by unveiling the photon ring
substructure in the nearest black holes.
