A TECHNIQUE FOR DETERMINING PLANETARY ATMOSPHERE STRUCTURE FROM MEASURED ACCELERATIONS OF AN ENTRY VEHICLE

摘要

Sample calculations were made to illustrate how well extreme model atmospheres for Mars could be defined by this technique. Results of the calculations showed that accelerometers designed to measure over the entire range of expected accelerations with an accuracy of 0.1 percent of full-scale capability would not provide sufficiently precise data to define all of the atmospheres that could be encountered within the possible extremes. If, however, the time period over which large errors in measured accelerations are encountered is reduced by means of an independent method for defining the atmosphere during the portion of the flight when the speed is relatively low or the acceleration measurements are improved by resorting to a dual system in which one set of instruments measures over the entire range of expected accelerations and the other over a more limited range, then any of the model atmospheres within the extremes can be determined reasonably well over extensive ranges of altitude. It is concluded that the method is worthy of further consideration as a means for surveying the atmospheres of the planets.