  First steps have been taken in a more comprehensive study of the dependence
of observables in Type I X-ray bursts on uncertain (p,gamma) reaction rates
along the rp-process path. We use the multizone hydrodynamics code KEPLER which
implicitly couples a full nuclear reaction network of more than 1000 isotopes,
as needed, to follow structure and evolution of the X-ray burst layer and its
ashes. This allows us to incorporate the full rp-process network, including all
relevant nuclear reactions, and individually study changes in the X-ray burst
light curves when modifying selected key nuclear reaction rates. In this work
we considered all possible proton captures to nuclei with 10 < Z < 28 and N <=
Z. When varying individual reaction rates within a symmetric full width
uncertainty of a factor of 10000, early results for some rates show changes in
the burst light curve as large as 10 percent of peak luminosity. This is very
large compared to the current sensitivity of X-ray observations. More precise
reaction rates are therefore needed to test current X-ray burst models,
particularly of the burst rise, with observational data and to constrain
astrophysical parameters.
