The Experimental Probe of Inflationary Cosmology - Intermediate Mission (EPIC-IM) is a concept for the NASA
Einstein Inflation Probe satellite. EPIC-IM is designed to characterize the polarization properties of the Cosmic
Microwave Background to search for the B-mode polarization signal characteristic of gravitational waves generated
during the epoch of Inflation in the early universe. EPIC-IM employs a large focal plane with 11,000 detectors operating
in 9 wavelength bands to provide 30 times higher sensitivity than the currently operating Planck satellite. The optical
design is based on a wide-field 1.4 m crossed-Dragone telescope, an aperture that allows not only comprehensive
measurements of Inflationary B-mode polarization, but also measurements of the E-mode and lensing polarization
signals to cosmological limits, as well as all-sky maps of Galactic polarization with unmatched sensitivity and angular
resolution. The optics are critical to measuring these extremely faint polarization signals, and any design must meet
demanding requirements on systematic error control. We describe the EPIC-IM crossed Dragone optical design, its
polarization properties, and far-sidelobe response.
CALISTO, the Cryogenic Aperture Large Infrared Space Telescope Observatory, will enable extraordinarily high
sensitivity far-infrared continuum and moderate (R ~ 1000) resolution spectroscopic observations at wavelengths from
~30µm to ~300 μm - the wavelengths between those accessible by JWST and future ground based facilities.
CALISTO's observations will provide vital information about a wide range of important astronomical questions
including (1) the first stars and initial heavy element production in the universe; (2) structures in the universe traced by
H2 emission; (3) the evolution of galaxies and the star formation within them (4) the formation of planetary systems
through observations of protostellar and debris disks; (5) the outermost portions of our solar system through observations
of Trans-Neptunian Objects (TNOs) and the Oort cloud. With optics cooled to below 5 K, the photon fluctuations from
the astronomical background (Zodiacal, Galactic, and extragalactic) exceed those from the telescope. Detectors with a
noise equivalent power below that set by the background will make possible astronomical-background-limited sensitivity
through the submillimeter/far-infrared region. CALISTO builds on studies for the SAFIR (Single Aperture Far Infrared)
telescope mission, employing a 4m x 6m off-axis Gregorian telescope which has a simple deployment using an Atlas V
launch vehicle. The unblocked telescope with a cold stop has minimal sidelobes and scattering. The clean beam will
allow astronomical background limited observations over a large fraction of the sky, which is what is required to achieve
CALISTO's exciting science goals. The maximum angular resolution varies from 1.2" at 30 µm to 12" at 300 μm. The
5σ 1 hr detectable fluxes are ▵S(dν/ν = 1.0) = 2.2x10-20 Wm-2, and ▵S(dν/ν = 0.001) = 6.2x10-22 Wm-2. The 8 beams per
source confusion limit at 70 μm is estimated to be 5 μJy. We discuss CALISTO optics, performance, instrument
complement, and mission design, and give an overview of key science goals and required technology development to
enable this promising far IR/submm mission.
We present a design for a cryogenically cooled large aperture telescope for far-infrared astronomy in the wavength
range 30 μm to 300 μm. The Cryogenic Aperture Large Infrared Space Telescope Observatory, or CALISTO, is
based on an off-axis Gregorian telesocope having a 4 m by 6 m primary reflector. This can be launched using an
Atlas V 511, with the only optical deployment required being a simple hinged rotation of the secondary reflector.
The off-axis design, which includes a cold stop, offers exceptionally good performance in terms of high efficiency
and minimum coupling of radiation incident from angles far off the direction of maximum response. This means
that strong astronomical sources, such as the Milky Way and zodiacal dust in the plane of the solar system,
add very little to the background. The entire optical system is cooled to 4 K to make its emission less than
even this low level of astronomical emission. Assuming that detector technology can be improved to the point
where detector noise is less than that of the astronomical background, we anticipate unprecedented low values
of system noise equivalent power, in the vicinity of 10-19 WHz-0.5, through CALISTO's operating range. This
will enable a variety of new astronomical investigations ranging from studies of objects in the outer solar system
to tracing the evolution of galaxies in the universe throughout cosmic time.
An integrated Large Deployable Reflector (LDR) analysis model was developed to enable studies of system responses to the mechanical and thermal disturbances anticipated during on-orbit operations. Functional requirements of the major subsystems of the LDR are investigated, design trades are conducted, and design options are proposed. System mass and inertia properties are computed in order to estimate environmental disturbances, and in the sizing of control system hardware. Scaled system characteristics are derived for use in evaluating launch capabilities and achievable orbits. It is concluded that a completely passive 20-m primary appears feasible for the LDR from the standpoint of both mechanical vibration and thermal distortions.