The Wide Field Infrared Survey Telescope (WFIRST), NASA’s next decadal astrophysics observatory, will enable advances in astrophysics by providing a large-scale survey capability in infrared wavelengths. The observatory is designed to capture data that will allow astronomers to unlock the mysteries of the universe, answering high-priority scientific questions related to the evolution of the universe and the habitability of exoplanets. Using a 2.4 m (7.9 ft) primary mirror, WFIRST will capture comparable quality images to the Hubble Space Telescope, but with more than 100 times the field of view, enabling the observatory to conduct comprehensive and efficient surveys of the infrared sky. Scientists estimate WFIRST has the potential to examine a billion galaxies over the course of its mission. Ball Aerospace was selected as NASA’s partner to design and develop the Wide Field Instrument (WFI) Opto-Mechanical Assembly for the WFIRST mission. The optical-mechanical assembly, which includes the optical bench, thermal control system, precision mechanisms, optics, electronics, and the relative calibration system, provides the stable structure and thermal environment that enables the wide-field, high quality observations of WFI. Ball's innovative design uses heritage hardware to unfold the incoming light, providing cost and schedule savings to the mission. In this paper, we present an overview of the WFI design, which completed its preliminary design review in June 2019. The overview includes a discussion of the design process, including several of the trade studies completed that led to the unfolded optical path architecture for the instrument design. The current state of the design is shown.
REMI (Reduced Envelope Multispectral Imager) is a new instrument developed by Ball Aerospace specifically for the Sustained Land Imaging (SLI) program. The goal of REMI is to meet the current Landsat mission requirements with a much smaller volume, lower cost payload. A lower single unit recurring cost enables economies of scale on multiple builds by leveraging non-recurring engineering costs. This lower cost enables multiple copies on-orbit at the same time for improved temporal sampling, an innovative approach to space segment reliability, and more frequent technology onramps. REMI achieves miniaturization through use of a common aperture for all spectral bands. REMI features a pointing mechanism that compensates for platform and ground motion while using cross-track, step-stare pointing to produce contiguous ground coverage in all spectral bands. The status of the REMI development and airborne flight testing will be presented.
The long-term stability of exoplanetary atmospheres depends critically on the extreme-ultraviolet (EUV) flux from the host star. The EUV flux likely controls the demographics of the short-period planet population as well the ability for rocky planets to maintain habitable environments long enough for the emergence of life. We present the Extreme-ultraviolet Stellar Characterization for Atmospheric Physics and Evolution (ESCAPE) mission, an astrophysics Small Explorer proposed to NASA. ESCAPE employs extreme- and far-ultraviolet spectroscopy (70 - 1800 Α) to characterize the highenergy radiation environment in the habitable zones (HZs) around nearby stars. ESCAPE provides the first comprehensive study of the stellar EUV environments that control atmospheric mass-loss and determine the habitability of rocky exoplanets. The ESCAPE instrument comprises an EUV grazing incidence telescope feeding four diffraction gratings and a photon-counting detector. The telescope is 50 cm diameter with four nested parabolic primary mirrors and four nested elliptical secondary mirrors, fabricated and aligned by NASA Marshall Space Flight Center and the Smithsonian Astrophysical Observatory. The off-plane grating assemblies are fabricated at Pennsylvania State University and the ESCAPE detector system is a micro-channel plate (MCP; 125mm x 40mm active area) sensor developed by the University of California, Berkeley. ESCAPE employs the versatile and high-heritage Ball Aerospace BCP-100 spacecraft.