The report identifies space- and ground-based research activities in three categories: large, midsize, and small. For large space activities -- those exceeding $1 billion -- an observatory the report calls the Wide-Field Infrared Survey Telescope (WFIRST) is the top priority because the space telescope would help settle fundamental questions about the nature of dark energy, determine the likelihood of other Earth-like planets over a wide range of orbital parameters, and survey our galaxy and others. For large-scale, ground-based research initiatives that exceed $135 million, the first priority is the Large Synoptic Survey Telescope (LSST), a wide-field optical survey telescope that would observe more than half the sky every four nights, and address diverse areas of study such as dark energy, supernovae, and time-variable phenomena...
Along with WFIRST, other priorities in the large-scale space category recommended in the report are an augmentation to the Explorer program, which supports small- and medium-sized missions that provide high scientific returns; the Laser Interferometer Space Antenna (LISA), which could enable detection of long gravitational waves or "ripples in space-time"; and the International X-Ray Observatory, a large-area X-ray telescope that could transform understanding of hot gas associated with stars, galaxies, and black holes in all evolutionary stages.
Other recommended ground-based research projects include the formation of a Midscale Innovations Program within the National Science Foundation (NSF), which would fill a funding gap for compelling research activities that cost between $4 million and $135 million. In addition, the report recommends participation in the U.S.-led international Giant Segmented Mirror Telescope, a next generation large optical telescope that is vital for continuing the long record of U.S. leadership in ground-based optical astronomy. The next priority is participation in an international ground-based high-energy gamma-ray telescope array.
For midsize space-based activities, the first priority is the New Worlds Technology Development Program, which lays the scientific groundwork for a future mission to study nearby Earth-like planets. Top priority for ground-based midsize research is the Cerro Chajnantor Atacama Telescope (CCAT), which would provide short wavelength radio surveys of the sky to study dusty material associated with galaxies and stars.
You can read it online for free: