The Midcourse Space Experiment (MSX) satellite is a space-based sensor platform primarily designed to collect data on the phenomenology of target detection and tracking. Because of the possible deleterious effect of contamination on these sensors, a suite of contamination monitoring instruments are also included in the satellite. These instruments are the Total Pressure Sensor (TPS), the Contamination Experiment Mass Spectrometer (CEMS), the Ion Mass Spectrometer (IMS), the Cryogenic Quartz Crystal Microbalance (CQCM), four Temperature-controlled Quartz Crystal Microbalance (TQCM), the Xenon Flashlamp Experiment (XFE), the Krypton Flashlamp Experiment (KFE) and the Spirit III Mirror Cleaning Experiment (SMCE). The philosophy of Contamination Experiment (CE), its calibration and testing, modeling and the data to be collected will be discussed.