20,356 research outputs found

    Habitable Exoplanet Observatory (HabEx) Telescope: Systems Engineering and STOP Modeling

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    The Habitable Exoplanet Observatory Mission (HabEx) is one of four missions studied for the 2020 Astrophysics Decadal Survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 115 to 1700 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving its science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is a 4-meter off-axis unobscured three-mirror-anastigmatic, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. This paper summarizes the opto-mechanical design of the baseline optical telescope assembly, including a discussion of how we applied science driven systems engineering to derive the telescopes engineering specifications from the missions science requirements, and presents analysis that the baseline telescope structure meets its specified tolerances

    HabEx Baseline Telescope: Design & Predicted Performance

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    Habitable Exoplanet Observatory Mission (HabEx) will image & spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by a 150 to 1700 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable telescope. The baseline HabEx telescope is a 4-m off-axis unobscured three-mirror-anastigmatic design with diffraction limited performance at 400 nm and wavefront stability of picometers per mK. These specifications are driven by science requirements. STOP (structural thermal optical performance) analysis predicts that the baseline telescopes opto-mechanical design meets its specified performance tolerances

    Orthogonal polynomials for area-type measures and image recovery

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    Let GG be a finite union of disjoint and bounded Jordan domains in the complex plane, let K\mathcal{K} be a compact subset of GG and consider the set GG^\star obtained from GG by removing K\mathcal{K}; i.e., G:=GKG^\star:=G\setminus \mathcal{K}. We refer to GG as an archipelago and GG^\star as an archipelago with lakes. Denote by {pn(G,z)}n=0\{p_n(G,z)\}_{n=0}^\infty and {pn(G,z)}n=0\{p_n(G^\star,z)\}_{n=0}^\infty, the sequences of the Bergman polynomials associated with GG and GG^\star, respectively; that is, the orthonormal polynomials with respect to the area measure on GG and GG^\star. The purpose of the paper is to show that pn(G,z)p_n(G,z) and pn(G,z)p_n(G^\star,z) have comparable asymptotic properties, thereby demonstrating that the asymptotic properties of the Bergman polynomials for GG^\star are determined by the boundary of GG. As a consequence we can analyze certain asymptotic properties of pn(G,z)p_n(G^\star,z) by using the corresponding results for pn(G,z)p_n(G,z), which were obtained in a recent work by B. Gustafsson, M. Putinar, and two of the present authors. The results lead to a reconstruction algorithm for recovering the shape of an archipelago with lakes from a partial set of its complex moments.Comment: 24 pages, 9 figure

    The support of the logarithmic equilibrium measure on sets of revolution in R3\R^3

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    For surfaces of revolution BB in R3\R^3, we investigate the limit distribution of minimum energy point masses on BB that interact according to the logarithmic potential log(1/r)\log (1/r), where rr is the Euclidean distance between points. We show that such limit distributions are supported only on the ``out-most'' portion of the surface (e.g., for a torus, only on that portion of the surface with positive curvature). Our analysis proceeds by reducing the problem to the complex plane where a non-singular potential kernel arises whose level lines are ellipses

    Cost Modeling for Space Telescope

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    Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models

    Reflections on My Time in the Wolfe Den

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    The three and a half years I spent as a member of the Infrared Group were transitional. Bill Wolfe was the nexus. Bill played a role in getting me to Arizona and keeping me there. He helped me advance professionally and taught me how to think like a systems engineer. He played a central role in my effort to earn a PhD. And, he helped start me in SPIE. This paper contains my personal and honest reflections on the impact which Bill Wolfe has had on me

    NASA SBIR Subtopic S2.04 "Advanced Optical Components"

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    The primary purpose of this subtopic is to develop and demonstrate technologies to manufacture ultra-low-cost precision optical systems for very large x-ray, UV/optical or infrared telescopes. Potential solutions include but are not limited to direct precision machining, rapid optical fabrication, slumping or replication technologies to manufacture 1 to 2 meter (or larger) precision quality mirror or lens segments (either normal incidence for uv/optical/infrared or grazing incidence for x-ray). An additional key enabling technology for UV/optical telescopes is a broadband (from 100 nm to 2500 nm) high-reflectivity mirror coating with extremely uniform amplitude and polarization properties which can be deposited on 1 to 3 meter class mirror

    The James Webb Space Telescope (JWST), The First Light Machine

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    Scheduled to begin its 10 year mission after 2018, the James Webb Space Telescope (JWST) will search for the first luminous objects of the Universe to help answer fundamental questions about how the Universe came to look like it does today. At 6.5 meters in diameter, JWST will be the world s largest space telescope. This talk reviews science objectives for JWST and how they drive the JWST architecture, e.g. aperture, wavelength range and operating temperature. Additionally, the talk provides an overview of the JWST primary mirror technology development and fabrication status
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