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A multi-discipline, multi-year collaborative spaceflight research program (NASA/Mir Science Program) has been established between the United States and Russia utilizing the capabilities of the Russian Mir Space Station and the NASA space shuttle fleet. As a key research discipline to be carried out onboard Mir, fundamental biology research encompasses three basic objectives: first, to investigate long-term effects of microgravity upon plant and avian physiology and developmental biology; second, to investigate the long-term effects of microgravity upon circadian rhythm patterns of biological systems; and third, to characterize the long-term radiation environment (internal and external) of the Russian Mir space station. The first joint U.S./Russian fundamental biology research on-board Mir is scheduled to begin in March, 1995 with the Mir mission 18 and conclude with the docking of the U.S. shuttle to Mir in June, 1995 during the STS-71, Spacelab/Mir Mission-1 (SLM-1).

The chemistry involved in the selective catalytic reduction of oxides of nitrogen (NOx) to nitrogen is outlined and the requirements of a practical NOx reduction catalyst are summarized. The effects of temperature, gas composition, NOx concentration, and sulfur dioxide on the activity of some potential NOx catalysts have been studied. Steady-state engine dynamometer endurance runs with ruthenium and non-ruthenium catalysts are described, and some vehicle durability data with particulate and monolithic base metal containing NOx catalysts are also presented.