National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite, Data, and Information Service (NESDIS) is responsible for verification and validation of ground system and product processing after the launch of each Polar Environmental Satellites (POES) spacecraft. NOAA/NESDIS works in conjunction with the National Aeronautics and Space Administration (NASA) On-Orbit Verification team which ensures the proper functioning of the satellite and each instrument before turn-over to NOAA. The post-launch verification/validation period following the launch of each satellite in the NOAA POES KLM satellite series presented a unique set of challenges. The NOAA-15 Advanced Microwave Sounder Unit-A Temperature Sounder (AMSU-A) cross-wiring problem and the NOAA-16 High Resolution Infrared Radiation Sounder (HIRS) pixel misalignment problem are two examples. This paper discusses some of these challenges, how they were overcome, and lessons applied to successive post-launch verification/validation phases.