The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s
  The Wide Field Infrared Survey Telescope (WFIRST) is a 2.4m space telescope
with a 0.281 deg^2 field of view for near-IR imaging and slitless spectroscopy
and a coronagraph designed for > 10^8 starlight suppresion. As background
information for Astro2020 white papers, this article summarizes the current
design and anticipated performance of WFIRST. While WFIRST does not have the UV
imaging/spectroscopic capabilities of the Hubble Space Telescope, for wide
field near-IR surveys WFIRST is hundreds of times more efficient. Some of the
most ambitious multi-cycle HST Treasury programs could be executed as routine
General Observer (GO) programs on WFIRST. The large area and time-domain
surveys planned for the cosmology and exoplanet microlensing programs will
produce extraordinarily rich data sets that enable an enormous range of
Archival Research (AR) investigations. Requirements for the coronagraph are
defined based on its status as a technology demonstration, but its expected
performance will enable unprecedented observations of nearby giant exoplanets
and circumstellar disks. WFIRST is currently in the Preliminary Design and
Technology Completion phase (Phase B), on schedule for launch in 2025, with
several of its critical components already in production.
