{'fraction_non_alphanumeric': 0.024199288256227757, 'fraction_numerical': 0.013523131672597865, 'mean_word_length': 5.361990950226244, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Flight Experiment To Measure Contamination Enhancement By Spacecraft Charging

The ML12 experiment was launched on January 30, 1979, on the United States Air Force (USAF) Space Test Program P78-2 spacecraft, which is sometimes called SCATHA. It was designed to determine if spacecraft charging contributes significantly to the rate that contaminants arrive at exterior spacecraft surfaces, and to establish some of the characteristics and effects of these contaminants. Two sensor types are used in the experiment. One type is a combination retarding potential analyzer (RPA) and temperature controlled quartz crystal microbalance (TQCM). With it, distinction can be made between charged and uncharged arriving molecules, and information can be obtained concerning the temperature dependence of contaminant adsorption and desorption rates. The other sensor type is a tray of calorimetrically mounted thermal control coating (TCC) samples. Samples of different spacecraft surface materials are exposed to arriving contaminants, and the solar absorptances (as) of these materials are continuously measured. The two RPA/TQCMs are both accumulating mass, but the accumulation rates and characteristics of the mass differ, probably because of the locations of the RPA/TQCMs on the spacecraft. Of the 16 TCC samples, two quartz fabric samples showed .01 to .05 increases in as during the first 50 days on orbit.