  We investigate the possibility of using the proposed SNAP satellite in
combination with low-z supernova searches to distinguish between different
inverse power-law quintessence models. If the true model is that of a
cosmological constant, we determine the prospects of ruling out the inverse
power-law potential. We show that SNAP combined with e.g. the SNfactory and an
independent measurement of the mass energy density to 17% accuracy can
distinguish between an inverse power-law potential and a cosmological constant
and put severe constraints on the power-law exponent.
