It was not until after World War II that new techniques of radar and radio astronomy led to a significant improvement in the accuracy of these experimental tests of general relativity. We can now say that the predictions of general relativity for the deflection (and also delay) of light passing the sun and for the orbital motion not only of Mercury but also of the asteroid Icarus and other natural and man-made bodies have been confirmed with experimental uncertainties less than 1%. But this was a long time in coming.
