Infrared spectroscopy is an invaluable detection and measurement tool intensively used in Earth Science, Solar Physics and Astrophysics experiments pursued from satellite platforms. The geometrical characteristics and sensitivity of satellite infrared spectroscopy systems is often determined or limited by their optical elements. Improvements in optical components allow one to reduce the mass and increase the sensitivity of the system. Here we propose a compact, high sensitivity sensor based on the integration of HgCdTe photodiode detection technology with micro-opto-electromechanical-systems (MOEMS) technology. This combines HgCdTe's high sensitivity with an inexpensive MOEMS lamellar grating interferometer (LGI) device. During Phase I we will perform the optical and mechanical design of the lamellar grating elements, identify suitable processes for fabrication, demonstrate etch processes compatible with the LGI design, and demonstrate prototype lamellar elements. During Phase II, we will further optimize the LGI components, minimize their size, weight and power, and integrate them into an operational LGI. A prototype LGI instrument will be deployed in an environment with controlled input of a variety of low-level test gases. We will develop and test detection-identification algorithms and build a characterization set-up to assess the LGI's sensitivity, selectivity and probability of detection.