December 31, 2019 Updates Posted on December 31, 2019June 28, 2020 by Doug Loss Mass constraints for 15 protoplanetary disks from HD 1-0 https://arxiv.org/abs/1912.11883 Setting Sail for the Sun: The NEA Scout & Solar Cruiser Missions https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190033998.pdf