  We study a new mechanism to dynamically break supersymmetry in the E8xE8
heterotic string. As discussed recently in the literature, a long-lived,
meta-stable non-supersymmetric vacuum can be achieved in an N=1 SQCD whose
spectrum contains a sufficient number of light fundamental flavors. In this
paper, we present, within the context of the hidden sector of the weakly and
strongly coupled heterotic string, a slope-stable, holomorphic vector bundle on
a Calabi-Yau threefold for which all matter fields are in the fundamental
representation and are massive at generic points in moduli space. It is shown,
however, that near certain subvarieties in the moduli space a sufficient number
of light matter fields can occur, providing an explicit heterotic model
realizing dynamical SUSY breaking. This is demonstrated for the low-energy
gauge group Spin(10). However, our methods immediately generalize to Spin(Nc),
SU(Nc), and Sp(Nc), for a wide range of color index Nc. Moduli stabilization in
vacua with a positive cosmological constant is briefly discussed.
