After an outgassing event, the Landsat 5 X-band transmitter prematurely shut off during a data downlink to the USGS Landsat Ground Station in Sioux Falls, SD. Specifically the backup Traveling Wave Tube Amplifier (TWTA), which is a downlink power amplifier for spacecraft telecommunications, tripped an Over Current Protection circuit. In 1987, a similar anomaly forced engineers to power down the primary transmitter. Landsat 5 data acquisitions are suspended until this problem can be resolved.
Safeguarding freshwater resources is crucial, and while scientists use a variety of ground-based techniques to gauge water quality, the Landsat program has provided water quality data from orbit for decades.