MDL instruments capable of precisely measuring the sources and emission rates of carbon dioxide and methane on Earth are now on Mars to carry out similar analyses. Next stop: Saturn and its moon Titan.
JPL and NASA have a long history of flying tunable diode laser spectrometers on Earth and planetary missions for atmospheric and trace gas analysis. Most of the semiconductor lasers of interest require unique characteristics that are often unavailable commercially. For this reason, MDL has been involved in the design and fabrication of space-qualified semiconductor lasers since its inception. Two significant accomplishments are the delivery of the first InGaAsP 2.06-μm distributed-feedback semiconductor laser for detection of water and carbon dioxide isotopes to the Mars Volatiles and Climate Surveyor (Mars’98 mission) and the delivery of the first 3.27-μm interband cascade laser for detection of methane and its isotopes. The latter is the heart of the tunable laser spectrometer on Mars Science Laboratory, launched on November 26, 2011.