A weak equivalence principle test on a suborbital rocket

Abstract

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 σ(η) < 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 (η ≠ 0) would have profound implications for physics, astrophysics and cosmology.