The MFLL is an airborne lidar system, a single-beam multi-pixel laser altimeter using PRN (Pseudo Random Noise) modulated fiber lasers. The instrument has been developed under a NASA ESTO (Earth Science Technology Office) IIP (Instrument Incubator Program) grant for Climate Change research and Exploration. The major goal of MFLL is to demonstrate the required lidar technology concept for the LAS (Laser Absorption Spectrometer) to be flown on the future spaceborne ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission of NASA. The airborne MFLL is the prototype of the future LAS instrument, it is also referred to as ITT's CO2 EDU (Engineering Development Unit) for ASCENDS. ITT Geospatial Systems of Fort Wayne, Indiana is the developer of the instrument. NASA/LaRC (Langley Research Center) in Hampton, VA is the operator of the MFLL instrument and is providing flight data analysis.