  We investigate the possibility that cosmic rays of energy larger than the
Greisen-Zatsepin-Kuzmin cutoff are not nucleons, but a new stable, massive,
hadron that appears in many extensions of the standard model. We focus
primarily on the S^0, a uds-gluino bound state. The range of the S^0 through
the cosmic background radiation is significantly longer than the range of
nucleons, and therefore can originate from sources at cosmoglogical distances.
