Physical Sciences Inc. (PSI) proposes to synthesize, characterize, and test new ionic liquids and formulations as lubricants for aerospace applications. The compounds will operate effectively at low temperatures with appropriate viscosities, high viscosity indices, large heat capacities, and high thermal decomposition temperatures. The innovative, versatile, lubricants will also have an extremely wide liquidus range, nearly zero vapor pressure, low friction coefficients, small wear effects, and low outgassing for long-term operational stability in aerospace systems. In the Phase II program, additional ionic liquids will be identified, synthesized, characterized, formulated with various additives, and tested as liquid lubricants and base lubricants in greases for use at low temperature. Their tribological performance will be evaluated in an aerospace system(s) for TRL 3.