1,382 research outputs found
Breaking the Cost Curve: Applying Lessons Learned from the James Webb Space Telescope Development to Build More Cost-Effective Large Space Telescopes in the Future
This paper looks at the key programmatic and technical drivers of the James Webb Space Telescope and assesses ways to building more cost-effective telescopes in the future. The paper evaluates the top level programmatics for JWST along with the key technical drivers from design through integration and testing. Actual data and metrics from JWST are studied to identify what ultimately drove cost on JWST. Finally, the paper assesses areas where applying lessons learned can reduce costs on future observatories and will provide better insights into critical areas to optimize for cost
End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture
Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it
A new paradigm for space astrophysics mission design
Pursuing ground breaking science in a highly cost-constrained environment presents new challenges to the development of future space astrophysics missions. Within the conventional cost models for large observatories, executing a flagship “mission after next” appears to be unstainable. To achieve our nation’s science ambitions requires a new paradigm of system design, development and manufacture. This paper explores the nature of the current paradigm and proposes a series of steps to guide the entire community to a sustainable future
High Efficiency Collector for Laser Plasma EUV Source.
Collector optics for an EUV radiation source for collecting EUV radiation. The collector optics includes an elliptical dish reflector where light generated at a focal point of the reflector and is directed to a collection location. A frustal annual reflector is positioned around an outer edge of the dish reflector to collect more of the EUV radiation that may otherwise be lost. The radiation reflected by the annual reflector is directed to a center axicon reflector positioned between the focal point of the dish reflector and the collection location to redirect the radiation reflected by the annual reflector to be within a predetermined collection angle
Active Figure Control Effects on Mounting Strategy for X-Ray Optics
As part of ongoing development efforts at MSFC, we have begun to investigate mounting strategies for highly nested xray optics in both full-shell and segmented configurations. The analytical infrastructure for this effort also lends itself to investigation of active strategies. We expect that a consequence of active figure control on relatively thin substrates is that errors are propagated to the edges, where they might affect the effective precision of the mounting points. Based upon modeling, we describe parametrically, the conditions under which active mounts are preferred over fixed ones, and the effect of active figure corrections on the required number, locations, and kinematic characteristics of mounting points
Monolithic Silicon EUV Collector
A collector optic assembly for a EUV radiation source. The collector optic assembly includes an elliptical meniscus having a reflective Si/Mo coating for collecting and reflecting EUV radiation generated by the source. The meniscus is machined from a single piece of silicon. The collector optic assembly further includes a heat exchanger that includes cooling channels through which flows a liquid coolant. The heat exchanger is fabricated from a plurality of machined silicon sections fused together by a glass frit bonding process. The meniscus is fused to a front side of the heat echanger by a glass frit bonding process. A liquid coolant inlet manifold and a liquid coolant outlet manifold are also each machined from a single silicon block and are mounted to a back side of the heat exchange
The Lynx X-Ray Observatory: Concept Study Overview and Status
Lynx, one of four strategic mission concepts under study for the 2020 Astrophysics Decadal Survey, will provide leaps in capability over previous and planned X-ray missions, and will provide synergistic observations in the 2030s to a multitude of space- and ground-based observatories across all wavelengths. Lynx will have orders of magnitude improvement in sensitivity, on-axis sub-arcsecond imaging with arcsecond angular resolution over a large field of view, and high-resolution spectroscopy for point-like and extended sources. The Lynx architecture enables a broad range of unique and compelling science, to be carried out mainly through a General Observer Program. This Program is envisioned to include detecting the very first supermassive black holes, revealing the high-energy drivers of galaxy and structure formation, characterizing the mechanisms that govern stellar activity - including effects on planet habitability, and exploring the highest redshift galaxy clusters. An overview and status of the Lynx concept are summarized
Interview with Rich Arenberg by Brien Williams
Biographical NoteRichard A. “Rich” Arenberg, the son of Bernard and Mary Arenberg, was born on October 16, 1945, in Norwich Connecticut. He was a campus activist during his undergraduate years at Boston University, and worked on some local campaigns, including the campaign of Tom Atkins, the first African American city councilor in Boston. He received a Ph.D. in political science also from Boston University and has a background in survey research. He worked as the issues director for Paul Tsongas’s first congressional campaign in Massachusetts and continued on Tsongas’s congressional and Senate staff until Tsongas retired from the Senate in 1984. At that point he was hired as Senator Mitchell’s chief of staff and was involved with the Congressional Committee Investigating the Iran-Contra Affair. He later collaborated with Senators Mitchell and Cohen to write the book Men of Zeal. At the time of this interview he was working for Senator Carl Levin of Michigan.
SummaryInterview includes discussion of: experiences as a staffer on Capitol Hill; Senator Mitchell’s decision-making style, in particular as compared to Senator Tsongas’s style; the role of a senator’s chief of staff; Democratic leadership positions in the Senate; the advantages of being a senator from a small state; Senator Mitchell’s ascent to the position of majority leader; the Iran-Contra Committee, Oliver North’s testimony, and Senator Mitchell’s questioning; the tension between pursuing justice and the public’s right to know regarding public scandals; collaborating with Senators Mitchell and Cohen on their book Men of Zeal and the two men’s distinct writing styles; the role of the deputy president pro tempore in the Senate; the tension between covert intelligence and democratic values, and the emphasis Mitchell placed on opening those issues up; the “Gang of Eight;” the congressional bunker at the Greenbrier Hotel; and the importance of pursuing solutions over partisan issues and the work Senator Mitchell did in that direction
Basal Gene Expression by Lung CD4+ T Cells in Chronic Obstructive Pulmonary Disease Identifies Independent Molecular Correlates of Airflow Obstruction and Emphysema Extent
Lung CD4+ T cells accumulate as chronic obstructive pulmonary disease (COPD) progresses, but their role in pathogenesis remains controversial. To address this controversy, we studied lung tissue from 53 subjects undergoing clinically-indicated resections, lung volume reduction, or transplant. Viable single-cell suspensions were analyzed by flow cytometry or underwent CD4+ T cell isolation, followed either by stimulation with anti-CD3 and cytokine/chemokine measurement, or by real-time PCR analysis. In lung CD4+ T cells of most COPD subjects, relative to lung CD4+ T cells in smokers with normal spirometry: (a) stimulation induced minimal IFN-γ or other inflammatory mediators, but many subjects produced more CCL2; (b) the T effector memory subset was less uniformly predominant, without correlation with decreased IFN-γ production. Analysis of unstimulated lung CD4+ T cells of all subjects identified a molecular phenotype, mainly in COPD, characterized by markedly reduced mRNA transcripts for the transcription factors controlling TH1, TH2, TH17 and FOXP3+ T regulatory subsets and their signature cytokines. This mRNA-defined CD4+ T cell phenotype did not result from global inability to elaborate mRNA; increased transcripts for inhibitory CD28 family members or markers of anergy; or reduced telomerase length. As a group, these subjects had significantly worse spirometry, but not DLCO, relative to subjects whose lung CD4+ T cells expressed a variety of transcripts. Analysis of mRNA transcripts of unstimulated lung CD4+ T cell among all subjects identified two distinct molecular correlates of classical COPD clinical phenotypes: basal IL-10 transcripts correlated independently and inversely with emphysema extent (but not spirometry); by contrast, unstimulated IFN-γ transcripts correlated independently and inversely with reduced spirometry (but not reduced DLCO or emphysema extent). Aberrant lung CD4+ T cells polarization appears to be common in advanced COPD, but also exists in some smokers with normal spirometry, and may contribute to development and progression of specific COPD phenotypes. Trial Registration ClinicalTrials.gov as NCT0028122
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