摘要:
An experiment set has been performed using the Progress-M spacecraft and a set of dedicated and non-dedicated maneuvers in the vicinity of the Mir space station. The purpose of the experiment was to acquire ultraviolet data from t...
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An experiment set has been performed using the Progress-M spacecraft and a set of dedicated and non-dedicated maneuvers in the vicinity of the Mir space station. The purpose of the experiment was to acquire ultraviolet data from the far-field glow of rocket exhaust plumes at very high altitudes. Ultraviolet imagery of the Progress main engine was acquired using a camera with a response function that peaked at 290 nm. The data show an intense near-field radiation accompanied by a low-level glow that exists over spatial scales of kilometers. The emission is attributed to the decay of the OH(A) state, presumably formed in reactive collisions of plume species with atmo- spheric atomic oxygen. While many observations were recorded of the main engine that is used on both the Progress-M and Soyuz-TM spacecraft, as well as the smaller attitude control system thrusters, two key main engine measurements are reported here. In the first measurement, the imager field of view was at a right angle to the plume axis, at a radial range of 9.2 km. The firing lasted 5.3 sec. In the second measurement of the main engine plume, the aspect angle varied from 173 to 168 deg while the range from the main engine to the Mir station ranged from 15 to 28 km. The firing lasted 244 sec in that case. In both measurements, the far- field emission was found to completely fill the imager field of view. A relatively sluggish rise of the far-field radiation was observed at ignition, as compared to the near-field radiation. The measurements of the far-field plume were calibrated using the irradiance of a known star. It was estimated that within the portion of the plume observed by the Imager, the plume radiated 30 and 150 W of power for the first and second measurements, respectively. These results are briefly compared with the requirements for OH(A) generation the H(2) O+O reaction.
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