Comparison tools for assessing the microgravity environment of space missions, carriers, and conditions

The microgravity environment of the NASA Shuttles and Russia's MArspace station have been measmed by specially designed _xeletometer systems. The need fca comparisons between different missions, vehicles, conditions, etc. has been addressed by the two uew tgcx_sses described in this paper. The Principal Conkuonmt Specual Analysis (PCSA) and Quasi-steady "Ihtee-dimensional Histogram (QTH) techniques provide the means to describe the microgravity acceleration environment of a long time span of data on a single plot. As described in this paper, the PCSA and QTH lechniques allow both the range mad the median of the micmgravity environment to be represented graphically on a single page. A variety of operating conditions may be made evident by using PCSA or QTH plots. The PCSA plot can help to distinquish between equipment operating full time or pan time, as well as show the variability of the magnitude and/ca frequency of an w_cleration source. A QTH plot unnmmizes the magnitude and one"ntation of the low-frequency acceleration vector. _ type of plot can show the microgravity effects of attitude, altitude, venting, etc.