The NASA Mass Change Designated Observable Study: Progress and Future Plans

The 2017-2027 US National Academy of Sciences Decadal Survey for Earth Science and Applications from Space classified mass change as one of five designated observables having the highest priority in terms of Earth observations required to better understand the Earth system over the next decade.  In response to this designation, NASA initiated multi-center studies with an overarching goal of defining observing system architectures for each designated observable.  Here, we discuss the progress made and future plans for the Mass Change Designated Observable study. Progress includes the development of a Science and Applications Traceability Matrix, a tool that links science objectives to measurement techniques and accuracies,  for the 15 science and applications objectives listed in the Decadal Survey, as well as the definition of as many as three different architectural classes for which to achieve those objectives.  We will describe the Value Framework that is under way to assess and evaluate each observing system architectural option.  Preliminary results assessing the science value versus cost/risk of observing system architectures will be presented. In addition, future plans for the Mass Change Designated Observable Study will be discussed.