GOES-18 (designated pre-launch as GOES-T) is the third of the "GOES-R Series", the current generation of weather satellites operated by the National Oceanic and Atmospheric Administration (NOAA).

[4] The GOES-R Series also continues the legacy Geostationary SAR (GEOSAR) function of the SARSAT system onboard NOAA's GOES satellites which has contributed to the rescue of thousands of individuals in distress.

In May 2018, NOAA announced that the recently launched GOES-17 satellite was suffering from a severe malfunction in its instrument cooling system which resulted in degraded performance of its infrared sensors.

Lockheed Martin had already completed assembly of GOES-T and had to remove the ABI instrument in October 2018 and ship it to its manufacturer, Harris Corporation, to be rebuilt.

[8] GOES-18 will undergo a "split" post-launch testing (PLT) phase that will get GOES-18 into position near the current GOES-West location in August 2022, so its Advanced Baseline Imager (ABI) data will be available for the "warm" period that degrades some GOES-17 imagery during the height of hurricane season.

[9] The transition plan allows for early operational use of GOES-18 ABI data after Beta maturity is achieved and incorporates radio frequency conflict mitigation between GOES-17 and GOES-18 and telemetry and command uplinks and downlinks.