  We describe a Galilean test of the weak equivalence principle, to be
conducted during the free fall portion of a sounding rocket flight. The test of
a single pair of substances is aimed at a measurement uncertainty of sigma(eta)
< 10^-16 after averaging the results of eight separate drops. The weak
equivalence principle measurement is made with a set of four laser gauges that
are expected to achieve 0.1 pm Hz^-1/2. The discovery of a violation (eta not
equal to 0) would have profound implications for physics, astrophysics, and
cosmology.
