A space-qualified, single-frequency oscillator operating at 1064 nm is a critical component for a number of active optical measurement systems that have been proposed for both ground and space-based NASA missions. These include metrology for space-based interferometers, direct detection wind lidar systems, atmospheric aerosol measurement systems, and differential absorption lidar (DIAL) systems for ozone measurement. These applications all require a frequency-stabilized cw 1064 nm oscillator with an output power in the 10-100 mW range. We propose to design and build a space-qualified version of the required laser oscillator. We will base our design on a diode-pumped microchip laser. It will incorporate both active temperature control and locking to a narrow molecular absorption to provide a high level of frequency stabilization. Redundant diode pumps, thermally and mechanically robust packing, and a careful choice of materials to minimize contamination effects will ensure the design will be space qualifiable. Our Phase I work will demonstrate that the key technology goals can be met in a space qualifiable design. In Phase II we will accomplish the detailed design, assembly, and qualification of a space-qualified single frequency laser that meets the required performance goals.