Description: We propose to develop a sensor for in-situ stable isotope analysis from a lander/rover on future planetary missions. The system will enable the collection of valuable information applicable to biosignature investigations, i.e., the search for evidence of life within the solar system. Current limitations to in-situ isotope measurements will be overcome by utilizing a hollow fiber optic based IR spectroscopy concept. This concept enables high precision measurements within the ultra-small sample volume (<<1ml) of the hollow fiber and has proven to be three orders of magnitude more sensitive in terms of required sample size than current state of the art isotope sensors. The proposed project will focus on transitioning the current lab-based technique to a small size, weight, and power (SWaP) device that can be operated unattended. Significant strides will be made in this direction through the use of optimized hollow fiber technology developed at OKSI. In Phase I, proposed concepts for improving the system performance, reducing the SWaP, and engineering a field-capable device will be proven and specific options down selected for full development in Phase II. A complete prototype will be produced to measure Carbon (C) and Sulfur (S) isotope ratios from solid rock samples in Phase II. The ability to generate simultaneous C and S isotope measurements from solid samples has great potential for assessing biosignatures relating to sulfate reducing organisms and organisms using simple C substrates (including methanogens, fermenters, and others). The sensitivity afforded by the proposed system would open up this capability to smaller samples than ever before measured as well as provide a potential device for remote deployment. This could be a significant development in the search for these biosignatures on other planets and near space objects as well as in the early Earth rock record.

Benefits: The isotope sensor resulting from this project will be developed to support efforts to search for evidence of life on future NASA missions. The research is specifically relevant to NASA Objective 2.3 which is to "Ascertain the content, origin, and evolution of the solar system and the potential for life elsewhere," as well as NASA Astrobiology Roadmap Goal 7: "Determine how to recognize signatures of life on other worlds and on Earth." In fact, NASA Astrobiology Roadmap Objective 7.1 is to "Learn how to recognize and interpret biosignatures which, if identified in samples from ancient rocks on Earth or from other planets, can help to detect and/or characterize ancient and/or present-day life." The anticipated technology would also be useful for the exploration of the Moon and asteroids, since it is able to quantify local variations in δ 13C, which have been observed in primitive meteorites, comets, and interplanetary dust particles when investigated at the microscale. The capillary absorption spectrometer (CAS) at the heart of the system will also provide a new high precision, ultra-low-volume sensor relevant to a range of other NASA applications. These include atmospheric sensing of Earth and other planets (e.g., Uranus) environmental sensing from a small UAV, analysis of soil bacteria related to Carbon cycle, as well as full elemental analysis of various microscopic-sized samples and organisms.

The CAS sensor to be developed under this project will provide an extremely attractive alternative to both isotope ratio mass spectrometers (IRMS) and cavity ring down spectrometers (CRDS). The CAS will be relatively inexpensive, require only picomoles of material, and under this project, will be developed to be easily portable and operated unattended. Such a system will fill niche markets in forensic analysis, environmental sensing, human breath analysis, and industrial process control. Furthermore, the new capabilities and features of the CAS will enable new applications in isotope and gas sensing that simply were not possible before.