SIRAS-G, the Spaceborne Infrared Atmospheric Sounder for Geosynchronous Earth Orbit – A Pathfinder for IR Imaging Spectroscopy from Space

The Spaceborne Infrared Sounder for Geosynchronous Earth Orbit (SIRAS-G) is an infrared spectrometer being developed at Ball Aerospace & Technologies under IIP that offers significant benefits for future Earth and planetary science missions. SIRAS-G, selected for development under NASA’s 2002 Instrument Incubator Program (IIP-4), is an instrument concept of lower mass and power than contemporary instruments offering enhanced capabilities for atmospheric temperature, water vapor, and trace gas column measurements. We are now in the second year of this three-year program. SIRAS-G utilizes grating spectrometers coupled with refractive IR cameras to provide high spectral and spatial resolution. The SIRAS-G concept is adaptable to airborne, low-Earth orbit and geosynchronous deployment. We present the status of the laboratory instrument development and discuss instrument concepts for potential future missions. For SIRAS-G, we are building a laboratory demonstration instrument all major subsystems. We present status on planned and on-going development activities, including the fabrication and testing of the reflective triplet objective, the aft-optics and FPA for the demonstration instrument.