Quartz crystal microbalance (QCM) flight measurements of contamination OR the MSX satellite

摘要

The Midcourse Space Experiment (MSX) satellite was launched into a 903 Km, 99.4-deg orbit April 24, 1996. It carries imaging spectrometers and radiometers that operate in the UV, visible, and infrared spectral ranges. In addition, it carries sev¬eral contamination measuring;instrument that are being used to characterize the contamination environment on, in, and around the satellite. Five are quartz crystal microbalances (QCMs), four of which are temperature-controlled (TQCMs). They are located on various external surfaces of the spacecraft and are operating at -40° to -50°C to measure the condensa¬tion of silicone and organic molecules. One is a cryogenic quartz crystal microbalance (CQCM) which is located adjacent to the SPIRIT Ⅲ infrared cryogenic telescope primary mirror. Its temperature followed the mirror which cooled from 28 to 20 K during the first week of operation. AH QCMs recorded deposition in die 10-20 ng/cm2-day (1-2 A/day) range. Thermo-gravimetric analyses on the QCMs provided insight into the amount and species of contaminants condensed. Data from the QCMs and other instruments in the contamination experiment (CE) suite played an important role in determining when it was safe to open covers on some of the optical instruments.