Testing the Strong Equivalence Principle with Mars Ranging Data

Anderson, John D.; Gross, Mark; Lau, Eunice L.; Nordtvedt, Kenneth L.; Turyshev, Slava G.

Testing the Strong Equivalence Principle with Mars Ranging Data

Authors

Anderson, John D.

Gross, Mark

Lau, Eunice L.

Nordtvedt, Kenneth L.

Turyshev, Slava G.

Description

The year 1996 will mark the initiation of a number of new space missions to the planet Mars from which we expect to obtain a rich set of data, including spacecraft radio tracking data. Anticipating these events, we have analyzed the feasibility of testing a violation of the strong equivalence principle (SEP) with Earth-Mars ranging. Using analytic and numerical methods, we have demonstrated that ranging data can provide a useful estimate of the SEP parameter $η$. Two estimates of the predicted accuracy are quoted, one based on conventional covariance analysis, and the other based on ``modified worst case'' analysis, which assumes that systematic errors dominate the experiment. If future Mars missions provide ranging measurements with an accuracy of $σ$ meters, after ten years of ranging the expected accuracy for the parameter $η$ will be of order $σ_η\approx (1-12)\times 10^{-4}σ$. In addition, these ranging measurements will provide a significantly improved determination of the mass of the Jupiter system, independent of the test of the {\small SEP} polarization effect.
4 pages; LaTeX; Talk given at the Second William Fairbank Conference