We present a plan to address the calibration needs of the Wide Field Instrument (WFI) on the Wide Field Infrared Space Telescope (WFIRST), for on on-orbit observations and ground testing. The science mission of WFI is based on a combination of large surveys, a Guest Observer program, and a strong archival research program.
The WFIRST Science Requirements Document delineates several data quality and calibration requirements for the Mission. The Calibration Plan aims to be prescriptive and predictive, discussing which observations will be needed and estimating the total time required to carry out such observations. We discuss these requirements from an instrumental perspective, and identify the measurements, observations, and analysis steps needed to achieve the desired calibration and data quality levels, especially in terms of on-orbit observations..
ATLAS (Astrophysics Telescope for Large Area Spectroscopy) Probe is a mission concept for a NASA probe-class space mission with primary science goal the definitive study of galaxy evolution through the capture of 300,000,000 galaxy spectra up to z=7. It is made of a 1.5-m Ritchey-Chretien telescope with a field of view of solid angle 0.4 deg2. The wavelength range is at least 1 μm to 4 μm with a goal of 0.9 μm to 5 μm. Average resolution is 600 but with a possible trade-off to get 1000 at the longer wavelengths. The ATLAS Probe instrument is made of 4 identical spectrographs each using a Digital Micro-mirror Device (DMD) as a multi-object mask. It builds on the work done for the ESA SPACE and Phase-A EUCLID projects. Three-mirror fore-optics re-image each sub-field on its DMD which has 2048 x 1080 mirrors 13.6 μm wide with 2 possible tilts, one sending light to the spectrograph, the other to a light dump. The ATLAS Probe spectrographs use prisms as dispersive elements because of their higher and more uniform transmission, their larger bandwidth, and the ability to control the resolution slope with the choice of glasses. Each spectrograph has 2 cameras. While the collimator is made of 4 mirrors, each camera is made of only one mirror which reduces the total number of optics. All mirrors are aspheric but with a relatively small P-V with respect to their best fit sphere making them easily manufacturable. For imaging, a simple mirror to replace the prism is not an option because the aberrations are globally corrected by the collimator and camera together which gives large aberrations when the mirror is inserted. An achromatic grism is used instead. There are many variations of the design that permit very different packaging of the optics. ATLAS Probe will enable ground-breaking science in all areas of astrophysics. It will (1) revolutionize galaxy evolution studies by tracing the relation between galaxies and dark matter from the local group to cosmic voids and filaments, from the epoch of reionization through the peak era of galaxy assembly; (2) open a new window into the dark universe by mapping the dark matter filaments to unveil the nature of the dark Universe using 3D weak lensing with spectroscopic redshifts, and obtaining definitive measurements of dark energy and modification of gravity using cosmic large-scale structure; (3) probe the Milky Way's dust-shrouded regions, reaching the far side of our Galaxy; and (4) characterize asteroids and other objects in the outer solar systems.
The Star Formation Camera (SFC) is a wide-field (~19'×~15', >280 arcmin2), high-resolution (18 mas pixels) UV/optical
dichroic camera designed for the Theia 4-m space-borne space telescope concept. SFC will deliver diffraction-limited
images at λ > 300 nm in both a blue (190-517nm) and a red (517-1075nm) channel simultaneously. The goal is to
conduct a comprehensive and systematic study of the astrophysical processes and environments relevant for the births
and life cycles of stars and their planetary systems, and to investigate the range of environments, feedback mechanisms,
and other factors that most affect the outcome of star and planet formation.
Filters for astronomical imaging traditionally have a simple bandpass that admits (more or less equally) all the
photons within some bandwith ▵λ around some central wavelength λ0. However, there are situations where
not all photons are equally desirable. We plan to develop and apply multiband filters for practical astronomical
application. A multiband filter is a bandpass filter whose transmission dips to zero at select, undesired wavelength
ranges. Anticipated applications include (i) OH-suppressing filters, especially in the J band (λc ≈ 1.2μm); (ii)
economy of filter slots through multi-band filters used in series with broad blocking filters; and (iii) efficient
searches for object classes with highly structured spectra. We present the design and anticipated photometric
properties of a prototype reduced-background JR filter, which we plan to buy and test in 2010.
The Star Formation Observatory (SFO) is a 1.65m space telescope that addresses pivotal components in the 2007 NASA
Science Plan, with a primary focus on Cosmic Origins. The design under consideration provides 100 times greater
imaging efficiency and >10 times greater spectroscopic efficiency below 115 nm than existed on previous missions. The
mission has a well-defined Origins scientific program at its heart: a statistically significant survey of local, intermediate,
and high-redshift sites and indicators of star formation, to investigate and understand the range of environments,
feedback mechanisms, and other factors that most affect the outcome of the star and planet formation process. This
program relies on focused capabilities unique to space and that no other planned NASA mission will provide: near-
UV/visible (20-1100 nm) wide-field, diffraction-limited imaging; and high-efficiency, low- and high- resolution (R~40,000) UV (100-175 nm) spectroscopy using far-UV optimized coatings and recent advances in Micro-Channel Plate
(MCP) detector technology. The Observatory imager has a field of view in excess of 17' × 17' (>250 arcmin2) and uses a
dichroic to create optimized UV/blue and red/near-IR channels for simultaneous observations, employing detectors that
offer substantial quantum efficiency gains and that suffer lower losses due to cosmic rays.