Completed Projects
Software Development
Probabilistic systems analysis
N&R has performed a number of probabilistic analyses of complex engineering systems with uncertainties identified at the component level. For example, our NASA-sponsored study investigated the impact of sub-system uncertainties and environmental uncertainties in the electrical power system of the International Space Station. The uncertainties included the Earth's albedo, the space station's positional attitude, battery capacity, the DC/DC converter efficiency, and the battery charge/discharge unit efficiency. The analysis results displayed to program managers a quantitative perspective of the available electrical power to be expected accounting for these uncertainties.
The results showed a mean power level (per panel) of 13.72 kwe with a 0.138 kwe standard deviation, although the power could vary between 13.2 and 14.2 kwe. The DDCU efficiency and the spacecraft attiude error are the most important uncertainties. This information helps mission operators plan the power allocation more effectively.
