I've heard that the radar data of Venus from Haystack was good enough to improve the orbital parameters of Jupiter.
A friend at the VLA reports that they ran into a glitch when they were helping NASA track an interplanetary probe. The data wasn't nearly as good as they were expecting. It all made sense after they updated their blue-shift corrections to start part way into the Earth's gravity well rather than at infinity.
GPS was a good test of Relativity, both Special and General. Without corrections, a 10 MHz signal derived from the clocks in the GPS satellites would be off by 4 mili-Hz. wiki
Fourth Test of Einstein's Theory of General Relativity at Haystack.