  We construct the graviton propagator on de Sitter background in exact de
Donder gauge. We prove that it must break de Sitter invariance, just like the
propagator of the massless, minimally coupled scalar. Our explicit solutions
for its two scalar structure functions preserve spatial homogeneity and
isotropy so that the propagator can be used within the larger context of
inflationary cosmology, however, it is simple to alter the residual symmetry.
Because our gauge condition is de Sitter invariant (although no solution for
the propagator can be) renormalization should be simpler using this propagator
than one based on a noncovariant gauge. It remains to be seen how other
computational steps compare.
