  We explore the possibility of obtaining de Sitter vacua in strongly coupled
heterotic models by adding various corrections to the supergravity potential
energy. We show that, in a generic compactification scenario, Fayet-Iliopoulos
terms can generate a de Sitter vacuum. The cosmological constant in this vacuum
can be fine tuned to be consistent with observation. We also study moduli
potentials in non-supersymmetric compactifications of $E_8 \times E_8$ theory
with anti five-branes and $E_8 \times \bar E_8$ theory. We argue that they can
be used to create a de Sitter vacuum only if some of the Kahler structure
moduli are stabilized at values much less than the Calabi-Yau scale.
