The Wide-Field Imager for Solar Probe (WISPR) is an imaging instrument of the Parker Solar Probe mission to the Sun, launched in August 2018.[1] Imaging targets include visible light images of the corona, solar wind, shocks, solar ejecta, etc.[1] Development of WISPR was led by the U.S. Naval Research Laboratory.[2] The Parker Solar Probe with WISPR on board was launched by a Delta IV Heavy on 12 August 2018 from Cape Canaveral, Florida.[3] WISPR is intended take advantage of the spacecraft's proximity to the Sun by taking coronagraph-style images of the solar corona and features like coronal streamers, plumes, and mass ejections.[4] One of the goals is to better understand the structure of the solar corona near the Sun.[4]
WISPR is designed to study the electron density and velocity structure of the corona.[5] The instrument field of view is planned to extend from 13 to 108 degrees away from the Sun, and does not directly image the Sun; the area of interest is a very wide field extending away from the Sun.[1]
WISPR includes two separate telescopes, each with a radiation-hardened CMOS imager with resolution of 2,048×1,920 pixels.[6] The CMOS sensors are an active pixel sensor type of detector.[7]
The WISPR first light image was published in September 2018.[8] In December, a view of the corona including a coronal streamer was released.[9]
In November 2018, a video of WIPSR recording solar wind during the spacecraft's first close pass to the Sun was released.[10] One project scientist noted, "The data we’re seeing from Parker Solar Probe’s instruments is showing us details about solar structures and processes that we have never seen before."[10]
The stray light and baffle for WISPR was modeled during development of the instrument.[11] Two noted cases where stray material caused issue with space imaging includes the Infrared Telescope (IRT) flown on the Space Shuttle Spacelab-2 mission, in which a piece of mylar insulation broke loose and floated into the line-of-sight of the telescope corrupting data.[12] This was on the STS-51-F in the year 1985.[12] Another case was in the 2010s on the Gaia spacecraft for which some stray light was identified coming from fibers of the sunshield, protruding beyond the edges of the shield.[13]