The Cross-track Infrared Sounder (CrIS) will provide improved atmospheric moisture and temperature profile measurements that can be used to improve the accuracy of future weather forecasts. Prior to launch, an extensive ground test and characterization program will be completed to build confidence that the sensor will be able carry out its mission. Flight model one (FM1) has been assembled and is now in testing. The testing is designed to insure that all the sensor requirements are being meet. First bench level tests will be completed; then the sensor will be placed in a thermal vacuum chamber to test the sensor under space like conditions. Performance tests that are planned include: measurement of the noise equivalent change in radiance (NEdN), radiometric stability, spectral stability, detector non-linearity, and instrument line shape (ILS) characterization and stability. In addition to performance and operational testing, the sensors will also be subject to numerous other tests such as EMI and launch level vibration tests.