  Planetary ephemerides have been developed and improved over centuries. They
are a fundamental tool for understanding solar system dynamics, and essential
for planetary and small body mass determinations, occultation predictions,
high-precision tests of general relativity, pulsar timing, and interplanetary
spacecraft navigation. This paper presents recent results from a continuing
program of high-precision astrometric very-long-baseline interferometry (VLBI)
observations of the Cassini spacecraft orbiting Saturn, using the Very Long
Baseline Array (VLBA). We have previously shown that VLBA measurements can be
combined with spacecraft orbit determinations from Doppler and range tracking
and VLBI links to the inertial extragalactic reference frame (ICRF) to provide
the most accurate barycentric positions currently available for Saturn. Here we
report an additional five years of VLBA observations along with improved phase
reference source positions, resulting in an improvement in residuals with
respect to the Jet Propulsion Laboratory's dynamical ephemeris.
