Friday, the Active Thermal Control (ATC) system brought key zones on the instrument up to their design operating temperatures. Very precise thermal control is necessary to ensure the proper sensor calibration once the science instruments are turned on later. The telemetry today showed that the ATC is working very well and the measured variations remained much smaller than the design requirements. The remainder of the work Friday was uploading and verifying the flight software patches. The telemetry showed that this was also going smoothly. Saturday's activities include uploading and installing the remaining software patches. The microwave radiometers are now scheduled to be turned on during a pass over the Alaska ground station beginning at 1803 UT Saturday. The first data downlink will be 4 hours later, after about 2.5 orbits.