We report the latest design, fabrication, and characterization results of the Next-Generation Microshutter Arrays (NGMSA) for space borne observatory applications. Our modified blade design aims to ...improve overall actuation torque by reducing the electrostatic force between free end of the shutter blade and the adjacent silicon frame, which generates counter torque at intermediate travel range, thus enables pure electrostatic actuation for more reliable and stable microshutter operations. This paper presents the experimental performance results of newly fabricated microshutter arrays with varying design parameters and compares the results with simulation predictions.
We present the first space flight use of the electrostatically actuated Next Generation MicroShutter Array systems (NGMSA) as multiple celestial object selectors developed for NASA space telescope ...missions at the NASA Goddard Space Flight Center. The NGMSA assembly was installed in the Next Generation Far-ultraviolet Off Rowland-circle Telescope for Imaging and Spectroscopy (NG-FORTIS) and successfully launched recently from the White Sands Missile Range in October 2019. We started to investigate this electrostatic NGMSA technology at the late stages of James Webb Space Telescope (JWST) in 2009 to strategically align with requirements of larger field of view for future telescopes in space. The NGMSA in NG-FORTIS is a 128 X 64 programable 2-D addressing microfabricated shutter array while the current NGMSA system under development is a 736 X 384 large format. The new microshutter array (MSA) features several unique designs aiming at performance improvements: electrostatic actuation, thinned microshutters, better electrical wall insulation and anti-stiction surface coating. To ensure reliable operation in the space environment, NGMSA systems have passed a series of critical environment tests including acoustic, random vibration, life cycle of operation, thermal cycling, and optical contrast tests. The successful launch of the NG-FORTIS sounding rocket equipped with NGMSA demonstrates our NGMSA technology have achieved the highest NASA Technical Readiness Level 9 for sounding rocket space applications.
Finding the UV–Visible Path Forward Scowen, Paul A.; Tripp, Todd; Beasley, Matt ...
Publications of the Astronomical Society of the Pacific,
07/2017, Letnik:
129, Številka:
977
Journal Article
Recenzirano
We present the science cases and technological discussions that came from the workshop titled “Finding the ultraviolet (UV)-Visible Path Forward” held at NASA GSFC 2015 June 25–26. The material ...presented outlines the compelling science that can be enabled by a next generation space-based observatory dedicated for UV–visible science, the technologies that are available to include in that observatory design, and the range of possible alternative launch approaches that could also enable some of the science. The recommendations to the Cosmic Origins Program Analysis Group from the workshop attendees on possible future development directions are outlined.
We present the science cases and technological discussions that came from the workshop titled "Finding the ultraviolet (UV)-Visible Path Forward" held at NASA GSFC 2015 June 25–26. The material ...presented outlines the compelling science that can be enabled by a next generation space-based observatory dedicated for UV–visible science, the technologies that are available to include in that observatory design, and the range of possible alternative launch approaches that could also enable some of the science. The recommendations to the Cosmic Origins Program Analysis Group from the workshop attendees on possible future development directions are outlined.
Partial frequency redistribution (PRD), describing the formation of the line profile, has negligible observational effects for optical depths smaller than {approx}10{sup 3}, at the resolving power of ...most current instruments. However, when the spectral resolution is sufficiently high, PRD modeling becomes essential in interpreting the line shapes and determining the total line fluxes. We demonstrate the effects of PRD on the H{sub 2} line profiles observed at high spectral resolution by the Far-Ultraviolet Spectroscopic Explorer (FUSE) in the atmospheres of Jupiter and Saturn. In these spectra, the asymmetric shapes of the lines in the Lyman (v''-6) progression pumped by the solar Ly{beta} are explained by coherent scattering of the photons in the line wings. We introduce a simple computational approximation to mitigate the numerical difficulties of radiative transfer with PRD and show that it reproduces the exact radiative transfer solution to better than 10%. The lines predicted by our radiative transfer model with PRD, including the H{sub 2} density and temperature distribution as a function of height in the atmosphere, are in agreement with the line profiles observed by FUSE. We discuss the observational consequences of PRD and show that this computational method also allows us to include PRD in modeling the continuum pumped H{sub 2} fluorescence treating about 4000 lines simultaneously.
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