By Scott Bachmeier •
Approximately once every 239 days, a HBT (Hydrazine Bipropellant Thruster) Flush is performed on GOES-R series satellites — this flushing burn limits the build-up of ferric nitrate in the HBT valves. Following a GOES-17 (GOES-West) HBT Flush that was conducted on 10 July 2019, a navigation offset of about 145 km was seen in 3 consecutive PACUS sector scans and in 2 consecutive Full Disk scans (immediately after the 10-minute image outage during the flush procedure) — a 5-minute PACUS sector view of Baja California using “Red” Visible (0.64 µm) images is shown above, and a 10-minute Full Disk sector view of thermal anomalies associated with wildfires in Alaska using Shortwave Infrared (3.9 µm) images is shown below. Additional information on the HBT can be found in the GOES-R Series Data Book.Categories: Calibration/Anomalies, GOES-17