The NASA Mass Change Designated Observable Study: Overview, Progress, and Future Plans. - David Wiese; Carmen Boening; Victor Zlotnicki; Scott B. Luthcke; Bryant D. Loomis; Matthew Rodell; Jeanne Sauber; David Bearden; Jonathan Chrone; Scott D. Horner; Frank Webb; Bernard Bienstock; et al. (IGARSS, 2020)