I am wondering if anyone knows of any internet-visible telemetry feeds that provide vehicle, science and/or sensor data? An example of one we have identified is the ISS http://spacestationlive.nasa.gov/ telemetry feed. thanks!
(note that 'telemetry' can mean a few different things ... for satellites, it's typically information about the location and other data about the operating status of the spacecraft)
NASA's STEREO mission makes their telemetry available. See :
Most science missions have such information available, as the spacecraft location and pointing is necessary for proper interpretation of the data. They'll also have other 'housekeeping' information (voltages, temperatures, etc.) which may be necessary for propler calibration.
You can find ephemeris data from other space science missions in the VSPO ... use the restriction 'Measurement Type' of 'Ephemeris'.
You can also compute spacecraft locations using SPICE.