Overview and Accomplishments of Advanced Mirror Technology Development Phase 2 (AMTD-2) Project

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2015-01-01

The Advance Mirror Technology Development (AMTD) project is in Phase 2 of a multiyear effort, initiated in FY12, to mature by at least a half TRL step critical technologies required to enable 4 meter or larger UVOIR space telescope primary mirror assemblies for both general astrophysics and ultra-high contrast observations of exoplanets. AMTD Phase 1 completed all of its goals and accomplished all of its milestones. AMTD Phase 2 started in 2014. Key accomplishments include deriving primary mirror engineering specifications from science requirements; developing integrated modeling tools and using those tools to perform parametric design trades; and demonstrating new mirror technologies via sub-scale fabrication and test. AMTD-1 demonstrated the stacked core technique by making a 43-cm diameter 400 mm thick 'biscuit-cut' of a 4-m class mirror. AMTD-2 is demonstrating lateral scalability of the stacked core method by making a 1.5 meter 1/3rd scale model of a 4-m class mirror.

Figure and Dimension Metrology of Extremely Lightweight X-Ray Mirrors for Space Astronomy Applications

NASA Technical Reports Server (NTRS)

Zhang, William W.

2010-01-01

The International X-ray Observatory (IXO) is the next major space X-ray observatory, performing both imaging and spectroscopic studies of all kinds of objects in the Universe. It is a collaborative mission of the National Aeronautics and Space Administration of the United States, the European Space Agency, and Japan Aerospace Exploration Agency. It is to be launched into a Sun-Earth L2 orbit in 2021. One of the most challenging aspects of the mission is the construction of a flight mirror assembly capable focusing X-rays in the band of 0.1 to 40 keY with an angular resolution of better than 5 arc-seconds and with an effective collection area of more than 3 sq m. The mirror assembly will consist of approximately 15,000 parabolic and hyperbolic mirror segments, each of which is approximately 200mm by 300mm with a thickness of 0.4mm. The manufacture and qualification of these mirror segments and their integration into the giant mirror assembly have been the objectives of a vigorous technology development program at NASA's Goddard Space Flight Center. Each of these mirror segments needs to be measured and qualified for both optical figure and mechanical dimensions. In this talk, I will describe the technology program with a particular emphasis on a measurement system we are developing to meet those requirements, including the use of coordinate measuring machines, Fizeau interferometers, and custom-designed, and -built null lens. This system is capable of measuring highly off-axis aspherical or cylindrical mirrors with repeatability, accuracy, and speed.

Engineering Specification for Large-aperture UVO Space Telescopes Derived from Science Requirements

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Postman, Marc; Smith, W. Scott

2013-01-01

The Advance Mirror Technology Development (AMTD) project is a three year effort initiated in FY12 to mature by at least a half TRL step six critical technologies required to enable 4 to 8 meter UVOIR space telescope primary mirror assemblies for both general astrophysics and ultra-high contrast observations of exoplanets. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system. To provide the science community with options, we are pursuing multiple technology paths. We have assembled an outstanding team from academia, industry, and government with extensive expertise in astrophysics and exoplanet characterization, and in the design/manufacture of monolithic and segmented space telescopes. A key accomplishment is deriving engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicles and their mass and volume constraints.

Progress making the top end optical assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope

NASA Astrophysics Data System (ADS)

Canzian, Blaise; Barentine, J.; Arendt, J.; Bader, S.; Danyo, G.; Heller, C.

2012-09-01

L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to design and produce the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakal', Maui. ATST will perform to a very high optical performance level in a difficult thermal environment. The TEOA, containing the 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, thermally managed Lyot stop, safety interlock and control system, and support frame, operates in the "hot spot" at the prime focus of the ATST and so presents special challenges. In this paper, we describe progress in the L-3 technical approach to meeting these challenges, including silicon carbide off-axis mirror design, fabrication, and high accuracy figuring and polishing all within L-3; mirror support design; the design for stray light control; subsystems for opto-mechanical positioning and high accuracy absolute mirror orientation sensing; Lyot stop design; and thermal management of all design elements to remain close to ambient temperature despite the imposed solar irradiance load.

Overview and Recent Accomplishments of the Advanced Mirror Technology Development (AMTD) for Large Aperture UVOIR Space Telescopes Project

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2013-01-01

Per Astro2010, a new, larger UVO telescope is needed to answer fundamental scientific questions, such as: is there life on Earth-like exoplanets; how galaxies assemble stellar populations; how baryonic matter interacts with intergalactic medium; and how solar systems form and evolve. And, present technology is not mature enough to affordably build and launch any potential UVO concept. Advanced Mirror Technology Development (AMTD) is a funded SAT project. Our objective is to mature to TRL-6 the critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable mission can be considered by the 2020 Decadal Review. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system. To provide the science community with options, we are pursuing multiple technology paths. We have assembled an outstanding team from academia, industry, and government with extensive expertise in astrophysics and exoplanet characterization, and in the design/manufacture of monolithic and segmented space telescopes. One of our key accomplishments is that we have derived engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicle and its inherent mass and volume constraints. We defined and initiated a program to mature 6 key technologies required to fabricate monolithic and segmented space mirrors.

Challenges and Approach for Making the Top End Optical Assembly for the 4-meter Advanced Technology Solar Telescope

NASA Astrophysics Data System (ADS)

Canzian, Blaise; Barentine, J.; Hull, T.

2012-01-01

L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to make the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakala, Maui. ATST will perform to a very high optical performance level in a difficult thermal environment. The TEOA, containing the 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, thermally managed Lyot stop, safety interlock and control system, and support frame, operates in the "hot spot” at the prime focus of the ATST and so presents special challenges. In this paper, we will describe the L-3 IOS technical approach to meet these challenges, including subsystems for opto-mechanical positioning, rejected and stray light control, wavefront tip-tilt compensation, and thermal management. Key words: ATST, TEOA, L-3 IOS, thermal management, silicon carbide (SiC) mirrors, hexapods, solar astronomy

CFRP composite optical telescope assembly for the 1 m ULTRA project

NASA Astrophysics Data System (ADS)

Martin, Robert N.; Romeo, Robert C.

2006-06-01

The focus of the ULTRA Project is to develop and test Ultra-Lightweight Technology for Research applications in Astronomy. The ULTRA project is a collaborative effort involving the private firm Composite Mirror Applications, Inc (CMA) and 3 universities: University of Kansas, San Diego State University, and Dartmouth College. Funding for ULTRA is predominately from a NSF three year MRI program grant to CMA and KU with additional support from CMA, KU and SDSU. The goal of the ULTRA program is to demonstrate that a viable alternative exists to traditional glass mirror and steel telescope technology by designing, fabricating and testing a research telescope constructed from carbon fiber reinforced plastic (CFRP) materials. In particular, a 1m diameter, Cassegrain telescope optics set and optical tube assembly (OTA) are being designed and fabricated by CMA. The completed telescope will be deployed at SDSU's Mt Laguna Observatory in a refurbished structure (new dome and mount provided via KU and SDSU). We expect that a successful completion and testing of this project will lead to future use of CFRP technology in larger telescopes and segmented telescopes. This paper describes the OTA (optical tube assembly) that has been developed for the ULTRA project. The mirror technology is described in another paper in this conference. A poster describes the ULTRA project overview in more detail.

High-Resolution and Lightweight X-ray Optics for the X-Ray Surveyor

NASA Astrophysics Data System (ADS)

Zhang, William

Envisioned in "Enduring Quest, Daring Visions" and under study by NASA as a potential major mission for the 2020s, the X-ray Surveyor mission will likely impose three requirements on its optics: (1) high angular resolution: 0.5 PSF, (2) large effective area: e10,000 cm2 or more, and (3) affordable production cost: $500M. We propose a technology that can meet these requirements by 2020. It will help the X-ray Surveyor secure the endorsement of the coming decadal survey and enable its implementation following WFIRST. The technology comprises four elements: (1) fabrication of lightweight single crystal silicon mirrors, (2) coating these mirrors with iridium to maximize effective area without figure degradation, (3) alignment and bonding of these mirrors to form meta-shells that will be integrated to make a mirror assembly, and (4) systems engineering to ensure that the mirror assembly meet all science performance and spaceflight environmental requirements. This approach grows out of our existing approach based on glass slumping. Using glass slumping technology, we have been able to routinely build and test mirror modules of 10half-power diameter (HPD). While comparable in HPD to XMM-Newtons electroformed nickel mirrors, these mirror modules are 10 times lighter. Likewise, while comparable in weight to Suzakus epoxy-replicated aluminum foil mirrors, these modules have 10 times better HPD. These modules represent the current state of the art of lightweight X-ray optics. Although both successful and mature, the glass slumping technology has reached its limit and cannot achieve sub-arc second HPD. Therefore, we are pursuing the new approach based on polishing single crystal silicon. The new approach will enable the building and testing of mirror modules, called meta-shells, capable of 3HPD by 2018 and 1HPD by 2020, and has the potential to reach diffraction limits ( 0.1) in the 2020s.

Feasibility of a 30-meter space based laser transmitter

NASA Technical Reports Server (NTRS)

Berggren, R. R.; Lenertz, G. E.

1975-01-01

A study was made of the application of large expandable mirror structures in future space missions to establish the feasibility and define the potential of high power laser systems for such applications as propulsion and power transmission. Application of these concepts requires a 30-meter diameter, diffraction limited mirror for transmission of the laser energy. Three concepts for the transmitter are presented. These concepts include consideration of continuous as well as segmented mirror surfaces and the major stow-deployment categories of inflatable, variable geometry and assembled-in-space structures. The mirror surface for each concept would be actively monitored and controlled to maintain diffraction limited performance at 10.6 microns during operation. The proposed mirror configurations are based on existing aerospace state-of-the-art technology. The assembled-in-space concept appears to be the most feasible, at this time.

A design study of mirror modules and an assembly based on the slumped glass for an Athena-like optics

NASA Astrophysics Data System (ADS)

Basso, Stefano; Civitani, Marta; Pareschi, Giovanni; Buratti, Enrico; Eder, Josef; Friedrich, Peter; Fürmetz, Maria

2015-09-01

The Athena mission was selected for the second large-class mission, due for launch in 2028, in ESA's Cosmic Vision program. The current solution for the optics is based on the Silicon Pore Optics (SPO) technology with the goal of 2m2 effective area at 1keV (aperture about 3m diameter) with a focal length of 12m. The SPO advantages are the compactness along the axial direction and the high conductivity of the Silicon. Recent development in the fabrication of mirror shells based on the Slumped Glass Optics (SGO) makes this technology an attractive solution for the mirror modules for Athena or similar telescopes. The SGO advantages are a potential high collecting area with a limited vignetting due to the lower shadowing and the aptitude to curve the glass plates up to small radius of curvature. This study shows an alternative mirror design based on SGO technology, tailored for Athena needs. The main challenges are the optimization of the manufacturing technology with respect to the required accuracy and the thermal control of the large surface in conjunction with the low conductivity of the glass. A concept has been elaborated which considers the specific benefits of the SGO technology and provides an efficient thermal control. The output of the study is a preliminary design substantiated by analyses and technological studies. The study proposes interfaces and predicts performances and budgets. It describes also how such a mirror system could be implemented as a modular assembly for X-ray telescope with a large collecting area.

By the Dozen: NASA's James Webb Space Telescope Mirrors

NASA Image and Video Library

2016-01-03

Caption: One dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. "This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently." Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.

By the Dozen: NASA's James Webb Space Telescope Mirrors

NASA Image and Video Library

2016-01-03

A view of the one dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. "This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently." Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year.

Modular Orbital Demonstration of an Evolvable Space Telescope

NASA Astrophysics Data System (ADS)

Baldauf, Brian

2016-06-01

The key driver for a telescope's sensitivityis directly related to the size of t he mirror area that collects light from the objects being observed.The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The HDST envisioned for this mission would have an aperture >10 m, which is a larger payload than can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. The Optical Telescope Assembly for HDST is a primary mission cost driver. Enabling affordable solutions for this next generation of large aperture space-based telescope are needed.This reports on the concept for the MODEST, which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, a testbed for new instruments, and a tool for student's exploration of space. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Ceramic Matrix Composite that have excellent mechanical and thermal properties, e.g. high stiffness, high thermal conductivity, and low thermal expansion. It has been demonstrated that mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making these materials excellent candidates for a low cost, high performance OTA.

Hybrid Electrostatic/Flextensional Mirror for Lightweight, Large-Aperture, and Cryogenic Space Telescopes

NASA Technical Reports Server (NTRS)

Patrick, Brian; Moore, James; Hackenberger, Wesley; Jiang, Xiaoning

2013-01-01

A lightweight, cryogenically capable, scalable, deformable mirror has been developed for space telescopes. This innovation makes use of polymer-based membrane mirror technology to enable large-aperture mirrors that can be easily launched and deployed. The key component of this innovation is a lightweight, large-stroke, cryogenic actuator array that combines the high degree of mirror figure control needed with a large actuator influence function. The latter aspect of the innovation allows membrane mirror figure correction with a relatively low actuator density, preserving the lightweight attributes of the system. The principal components of this technology are lightweight, low-profile, high-stroke, cryogenic-capable piezoelectric actuators based on PMN-PT (piezoelectric lead magnesium niobate-lead titanate) single-crystal configured in a flextensional actuator format; high-quality, low-thermal-expansion polymer membrane mirror materials developed by NeXolve; and electrostatic coupling between the membrane mirror and the piezoelectric actuator assembly to minimize problems such as actuator print-through.

Monocrystalline silicon and the meta-shell approach to building x-ray astronomical optics

NASA Astrophysics Data System (ADS)

Zhang, William W.; Allgood, Kim D.; Biskach, Michael P.; Chan, Kai-Wing; Hlinka, Michal; Kearney, John D.; Mazzarella, James R.; McClelland, Ryan S.; Numata, Ai; Olsen, Lawrence G.; Riveros, Raul E.; Saha, Timo T.; Solly, Peter M.

2017-08-01

Angular resolution and photon-collecting area are the two most important factors that determine the power of an X-ray astronomical telescope. The grazing incidence nature of X-ray optics means that even a modest photon-collecting area requires an extraordinarily large mirror area. This requirement for a large mirror area is compounded by the fact that X-ray telescopes must be launched into, and operated in, outer space, which means that the mirror must be both lightweight and thin. Meanwhile the production and integration cost of a large mirror area determines the economical feasibility of a telescope. In this paper we report on a technology development program whose objective is to meet this three-fold requirement of making astronomical X-ray optics: (1) angular resolution, (2) photon-collecting area, and (3) production cost. This technology is based on precision polishing of monocrystalline silicon for making a large number of mirror segments and on the metashell approach to integrate these mirror segments into a mirror assembly. The meta-shell approach takes advantage of the axial or rotational symmetry of an X-ray telescope to align and bond a large number of small, lightweight mirrors into a large mirror assembly. The most important features of this technology include: (1) potential to achieve the highest possible angular resolution dictated by optical design and diffraction; and (2) capable of implementing every conceivable optical design, such as Wolter-I, WolterSchwarzschild, as well as other variations to one or another aspect of a telescope. The simplicity and modular nature of the process makes it highly amenable to mass production, thereby making it possible to produce very large X-ray telescopes in a reasonable amount of time and at a reasonable cost. As of June 2017, the basic validity of this approach has been demonstrated by finite element analysis of its structural, thermal, and gravity release characteristics, and by the fabrication, alignment, bonding, and X-ray testing of mirror modules. Continued work in the coming years will raise the technical readiness of this technology for use by SMEX, MIDEX, Probe, as well as major flagship missions.

Monocrystalline Silicon and the Meta-Shell Approach to Building X-Ray Astronomical Optics

NASA Technical Reports Server (NTRS)

Zhang, William W.; Allgood, Kim D.; Biskach, Michael P.; Chan, Kai-Wing; Hlinka, Michal; Kearney, John D.; Mazzarella, James R.; McClelland, Ryan S.; Numata, Ai; Olsen, Lawrence G.;

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, an MSFC employee is inspecting one of many segments of the mirror assembly for flaws. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

NASA Astrophysics Data System (ADS)

Baldauf, Brian; Conti, Alberto

2016-01-01

The "Search for Life" via imaging of exoplanets is a mission that requires extremely stable telescopes with apertures in the 10 m to 20 m range. The High Definition Space Telescope (HDST) envisioned for this mission would have an aperture >10 m, which is a larger payload than what can be delivered to space using a single launch vehicle. Building and assembling the mirror segments enabling large telescopes will likely require multiple launches and assembly in space. Space-based telescopes with large apertures will require major changes to system architectures.The Optical Telescope Assembly (OTA) for HDST is a primary mission cost driver. Enabling and affordable solutions for this next generation of large aperture space-based telescope are needed.This paper reports on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST), which demonstrates on-orbit robotic and/or astronaut assembly of a precision optical telescope in space. It will also facilitate demonstration of active correction of phase and mirror shape. MODEST is proposed to be delivered to the ISS using standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets. Post-assembly value includes space, ground, and environmental studies, and a testbed for new instruments. This demonstration program for next generation mirror technology provides significant risk reduction and demonstrates the technology in a six-mirror phased telescope. Other key features of the demonstration include the use of an active primary optical surface with wavefront feedback control that allows on-orbit optimization and demonstration of precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal conductivity, and low thermal expansion. It has been demonstrated that mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making these materials excellent candidates for a low cost, high performance OTA.

Experimental evaluation of the ring focus test for X-ray telescopes using AXAF's technology mirror assembly, MSFC CDDF Project No. H20

NASA Technical Reports Server (NTRS)

Zissa, D. E.; Korsch, D.

1986-01-01

A test method particularly suited for X-ray telescopes was evaluated experimentally. The method makes use of a focused ring formed by an annular aperture when using a point source at a finite distance. This would supplement measurements of the best focus image which is blurred when the test source is at a finite distance. The telescope used was the Technology Mirror Assembly of the Advanced X-ray Astrophysis Facility (AXAF) program. Observed ring image defects could be related to the azimuthal location of their sources in the telescope even though in this case the predicted sharp ring was obscured by scattering, finite source size, and residual figure errors.

Stable mirror mount

DOEpatents

Cutburth, R.W.

1983-11-04

An improved mirror mount assembly is disclosed. The mirror mount assembly provides a post assembly slidable in a Y-axis orientation and a nut plate assembly slidable in an X-axis orientation and means for simultaneously locking said post assembly and said key assembly in a fixed position.

James Webb Space Telescope Optical Telescope Element Mirror Development History and Results

NASA Technical Reports Server (NTRS)

Feinber, Lee D.; Clampin, Mark; Keski-Kuha, Ritva; Atkinson, Charlie; Texter, Scott; Bergeland, Mark; Gallagher, Benjamin B.

2012-01-01

In a little under a decade, the James Webb Space Telescope (JWST) program has designed, manufactured, assembled and tested 21 flight beryllium mirrors for the James Webb Space Telescope Optical Telescope Element. This paper will summarize the mirror development history starting with the selection of beryllium as the mirror material and ending with the final test results. It will provide an overview of the technological roadmap and schedules and the key challenges that were overcome. It will also provide a summary or the key tests that were performed and the results of these tests.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, one of many segments of the mirror assembly is being set up inside the 24-ft vacuum chamber where it will undergo x-ray calibration tests. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Stable mirror mount

DOEpatents

Cutburth, Ronald W.

1990-01-01

An improved mirror mount assembly is disclosed. The mirror mount assembly provides a post assembly slidable in a Y-axis orientation and a nut plate assembly slidable in an X-axis orientation and a device for simultaneously locking the post assembly and the key assembly in a fixed position.

The Advanced Technology Solar Telescope mount assembly

NASA Astrophysics Data System (ADS)

Warner, Mark; Cho, Myung; Goodrich, Bret; Hansen, Eric; Hubbard, Rob; Lee, Joon Pyo; Wagner, Jeremy

2006-06-01

When constructed on the summit of Haleakala on the island of Maui, Hawaii, the Advanced Technology Solar Telescope (ATST) will be the world's largest solar telescope. The ATST is a unique design that utilizes a state-of-the-art off-axis Gregorian optical layout with five reflecting mirrors delivering light to a Nasmyth instrument rotator, and nine reflecting mirrors delivering light to an instrument suite located on a large diameter rotating coude lab. The design of the telescope mount structure, which supports and positions the mirrors and scientific instruments, has presented noteworthy challenges to the ATST engineering staff. Several novel design solutions, as well as adaptations of existing telescope technologies to the ATST application, are presented in this paper. Also shown are plans for the control system and drives of the structure.

By the Dozen: NASA's James Webb Space Telescope Mirrors

NASA Image and Video Library

2017-12-08

A view of the one dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. "This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently." Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year. Read more: www.nasa.gov/feature/goddard/2016/by-the-dozen-nasas-jame... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

By the Dozen: NASA's James Webb Space Telescope Mirrors

NASA Image and Video Library

2016-01-07

Caption: One dozen (out of 18) flight mirror segments that make up the primary mirror on NASA's James Webb Space Telescope have been installed at NASA's Goddard Space Flight Center. Credits: NASA/Chris Gunn More: Since December 2015, the team of scientists and engineers have been working tirelessly to install all the primary mirror segments onto the telescope structure in the large clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The twelfth mirror was installed on January 2, 2016. "This milestone signifies that all of the hexagonal shaped mirrors on the fixed central section of the telescope structure are installed and only the 3 mirrors on each wing are left for installation," said Lee Feinberg, NASA's Optical Telescope Element Manager at NASA Goddard. "The incredibly skilled and dedicated team assembling the telescope continues to find ways to do things faster and more efficiently." Each hexagonal-shaped segment measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). After being pieced together, the 18 primary mirror segments will work together as one large 21.3-foot (6.5-meter) mirror. The primary mirror will unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium. The mirrors are placed on the telescope's backplane using a robotic arm, guided by engineers. The full installation is expected to be completed in a few months. The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors onto the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope. While the mirror assembly is a very significant milestone, there are many more steps involved in assembling the Webb telescope. The primary mirror and the tennis-court-sized sunshield are the largest and most visible components of the Webb telescope. However, there are four smaller components that are less visible, yet critical. The instruments that will fly aboard Webb - cameras and spectrographs with detectors able to record extremely faint signals — are part of the Integrated Science Instrument Module (ISIM), which is currently undergoing its final cryogenic vacuum test and will be integrated with the mirror later this year. Read more: www.nasa.gov/feature/goddard/2016/by-the-dozen-nasas-jame... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Design and Analysis of Modules for Segmented X-Ray Optics

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; BIskach, Michael P.; Chan, Kai-Wing; Saha, Timo T; Zhang, William W.

2012-01-01

Future X-ray astronomy missions demand thin, light, and closely packed optics which lend themselves to segmentation of the annular mirrors and, in turn, a modular approach to the mirror design. The modular approach to X-ray Flight Mirror Assembly (FMA) design allows excellent scalability of the mirror technology to support a variety of mission sizes and science objectives. This paper describes FMA designs using slumped glass mirror segments for several X-ray astrophysics missions studied by NASA and explores the driving requirements and subsequent verification tests necessary to qualify a slumped glass mirror module for space-flight. A rigorous testing program is outlined allowing Technical Development Modules to reach technical readiness for mission implementation while reducing mission cost and schedule risk.

Silicon pore optics for the international x-ray observatory

NASA Astrophysics Data System (ADS)

Wille, E.; Wallace, K.; Bavdaz, M.; Collon, M. J.; Günther, R.; Ackermann, M.; Beijersbergen, M. W.; Riekerink, M. O.; Blom, M.; Lansdorp, B.; de Vreede, L.

2017-11-01

Lightweight X-ray Wolter optics with a high angular resolution will enable the next generation of X-ray telescopes in space. The International X-ray Observatory (IXO) requires a mirror assembly of 3 m2 effective area (at 1.5 keV) and an angular resolution of 5 arcsec. These specifications can only be achieved with a novel technology like Silicon Pore Optics, which is developed by ESA together with a consortium of European industry. Silicon Pore Optics are made of commercial Si wafers using process technology adapted from the semiconductor industry. We present the manufacturing process ranging from single mirror plates towards complete focusing mirror modules mounted in flight configuration. The performance of the mirror modules is tested using X-ray pencil beams or full X-ray illumination. In 2009, an angular resolution of 9 arcsec was achieved, demonstrating the improvement of the technology compared to 17 arcsec in 2007. Further development activities of Silicon Pore Optics concentrate on ruggedizing the mounting system and performing environmental tests, integrating baffles into the mirror modules and assessing the mass production.

Large Deployable Reflector (LDR) system concept and technology definition study. Volume 2: Technology assessment and technology development plan

NASA Technical Reports Server (NTRS)

Agnew, Donald L.; Jones, Peter A.

1989-01-01

A study was conducted to define reasonable and representative LDR system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume presents thirteen technology assessments and technology development plans, as well as an overview and summary of the LDR concepts. Twenty-two proposed augmentation projects are described (selected from more than 30 candidates). The five LDR technology areas most in need of supplementary support are: cryogenic cooling; astronaut assembly of the optically precise LDR in space; active segmented primary mirror; dynamic structural control; and primary mirror contamination control. Three broad, time-phased, five-year programs were synthesized from the 22 projects, scheduled, and funding requirements estimated.

Point Relay Scanner Utilizing Ellipsoidal Mirrors

NASA Technical Reports Server (NTRS)

Manhart, Paul K. (Inventor); Pagano, Robert J. (Inventor)

1997-01-01

A scanning system uses a polygonal mirror assembly with each facet of the polygon having an ellipsoidal mirror located thereon. One focal point of each ellipsoidal mirror is located at a common point on the axis of rotation of the polygonal mirror assembly. As the mirror assembly rotates. a second focal point of the ellipsoidal mirrors traces out a scan line. The scanner can be utilized for scanned output display of information or for scanning information to be detected.

Amorphous Metals and Composites as Mirrors and Mirror Assemblies

NASA Technical Reports Server (NTRS)

Hofmann, Douglas C. (Inventor); Davis, Gregory L. (Inventor); Agnes, Gregory S. (Inventor); Shapiro, Andrew A. (Inventor)

2016-01-01

A mirror or mirror assembly fabricated by molding, pressing, assembling, or depositing one or more bulk metal glass (BMG), bulk metal glass composite (BMGMC), or amorphous metal (AM) parts and where the optical surface and backing of the mirror can be fabricated without machining or polishing by utilizing the unique molding capabilities of this class of materials.

Research study entitled advanced X-ray astrophysical observatory (AXAF). [system engineering for a total X-ray telescope assembly

NASA Technical Reports Server (NTRS)

Rasche, R. W.

1979-01-01

General background and overview material are presented along with data from studies performed to determine the sensitivity, feasibility, and required performance of systems for a total X-ray telescope assembly. Topics covered include: optical design, mirror support concepts, mirror weight estimates, the effects of l g on mirror elements, mirror assembly resonant frequencies, optical bench considerations, temperature control of the mirror assembly, and the aspect determination system.

Fabrication of large aperture SiC brazing mirror

NASA Astrophysics Data System (ADS)

Li, Ang; Wang, Peipei; Dong, Huiwen; Wang, Peng

2016-10-01

The SiC brazing mirror is the mirror whose blank is made by assembling together smaller SiC pieces with brazing technique. Using such kinds of joining techniques, people can manufacture large and complex SiC assemblies. The key technologies of fabricating and testing SiC brazing flat mirror especially for large aperture were studied. The SiC brazing flat mirror was ground by smart ultrasonic-milling machine, and then it was lapped by the lapping smart robot and measured by Coordinate Measuring Machine (CMM). After the PV of the surface below 4um, we did classic coarse polishing to the surface and studied the shape of the polishing tool which directly effects removal amount distribution. Finally, it was figured by the polishing smart robot and measured by Fizeau interferometer. We also studied the influence of machining path and removal functions of smart robots on the manufacturing results and discussed the use of abrasive in this process. At last, an example for fabricating and measuring a similar SiC brazing flat mirror with the aperture of 600 mm made by Shanghai Institute of Ceramics was given. The mirror blank consists of 6 SiC sectors and the surface was finally processed to a result of the Peak-to-Valley (PV) 150nm and Root Mean Square (RMS) 12nm.

Advanced Mirror Technology Development (AMTD) Project: 3.0 Year Status

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2015-01-01

Advanced Mirror Technology Development (AMTD) is a funded NASA Strategic Astrophysics Technology project. Begun in 2011, we are in Phase 2 of a multi-year effort. Our objective is to mature towards TRL6 critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable astronomy mission can be considered by the 2020 Decadal Review. The developed technology must enable missions capable of both general astrophysics and ultra-high contrast observations of exoplanets. Just as JWST's architecture was driven by launch vehicle, a future UVOIR mission's architecture (monolithic, segmented or interferometric) will depend on capacities of future launch vehicles (and budget). Since we cannot predict the future, we must prepare for all potential futures. Therefore, we are pursuing multiple technology paths. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system. One of our key accomplishments is that we have derived engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicle and its inherent mass and volume constraints. Another key accomplishment is that we have matured our technology by building and testing hardware. To demonstrate stacked core technology, we built a 400 mm thick mirror. Currently, to demonstrate lateral scalability, we are manufacturing a 1.5 meter mirror. To assist in architecture trade studies, the Engineering team develops Structural, Thermal and Optical Performance (STOP) models of candidate mirror assembly systems including substrates, structures, and mechanisms. These models are validated by test of full- and subscale components in relevant thermo-vacuum environments. Specific analyses include: maximum mirror substrate size, first fundamental mode frequency (i.e., stiffness) and mass required to fabricate without quilting, survive launch, and achieve stable pointing and maximum thermal time constant.

Opto-Mechanical Analyses for Performance Optimization of Lightweight Grazing-Incidence Mirrors

NASA Technical Reports Server (NTRS)

Roche, Jacqueline; Kolodziejczak, Jeff; Odell, Steve; Eisner, Ronald; Ramsey, Brian; Gubarev, Mikhail

2013-01-01

New technology in grazing-incidence mirror fabrication and assembly is necessary to achieve sub-arcsecond optics for large-area x-ray telescopes. In order to define specifications, an understanding of performance sensitivity to design parameters is crucial. MSFC is undertaking a systematic study to specify a mounting approach, mirror substrate, and testing method. Because the lightweight mirrors are typically flimsy, they are susceptible to significant distortion due to mounting and gravitational forces. Material properties of the mirror substrate along with its thickness and dimensions significantly affect the distortions caused by mounting and gravity. A parametric study of these properties and their relationship to mounting and testing schemes will indicate specifications for the design of the next generation of lightweight grazing-incidence mirrors. Initial results will be reported.

Opto-mechanical Analyses for Performance Optimization of Lightweight Grazing-incidence Mirrors

NASA Technical Reports Server (NTRS)

Roche, Jacqueline M.; Kolodziejczak, Jeffery J.; Odell, Stephen L.; Elsner, Ronald F.; Weisskopf, Martin C.; Ramsey, Brian; Gubarev, Mikhail V.

2013-01-01

New technology in grazing-incidence mirror fabrication and assembly is necessary to achieve subarcsecond optics for large-area x-ray telescopes. In order to define specifications, an understanding of performance sensitivity to design parameters is crucial. MSFC is undertaking a systematic study to specify a mounting approach, mirror substrate, and testing method. Lightweight mirrors are typically flimsy and are, therefore, susceptible to significant distortion due to mounting and gravitational forces. Material properties of the mirror substrate along with its dimensions significantly affect the distortions caused by mounting and gravity. A parametric study of these properties and their relationship to mounting and testing schemes will indicate specifications for the design of the next generation of lightweight grazing-incidence mirrors. Here we report initial results of this study.

Opto-mechanical Analyses for Performance Optimization of Lightweight Grazing-incidence Mirrors

NASA Technical Reports Server (NTRS)

Roche, Jacqueline; Kolodsiejczak, Jeffrey; Odell, Stephen; Elsner, Ronald; Weisskopf, Martin; Ramsey, Brian; Gubarev, Mikhail

2013-01-01

New technology in grazing-incidence mirror fabrication and assembly is necessary to achieve sub-arcsecond optics for large-area x-ray telescopes. In order to define specifications, an understanding of performance sensitivity to design parameters is crucial. MSFC is undertaking a systematic study to specify a mounting approach, mirror substrate, and testing method. Because the lightweight mirrors are typically flimsy, they are susceptible to significant distortion due to mounting and gravitational forces. Material properties of the mirror substrate along with its thickness and dimensions significantly affect the distortions caused by mounting and gravity. A parametric study of these properties and their relationship to mounting and testing schemes will indicate specifications for the design of the next generation of lightweight grazing-incidence mirrors. Initial results will be reported.

Segmented X-Ray Optics for Future Space Telescopes

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.

2013-01-01

Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of approx.17 sq cm/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

Toward Large-Area Sub-Arcsecond X-Ray Telescopes II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Allured, Ryan; Ames, Andrew O.; Biskach, Michael P.; Broadway David M.; Bruni, Ricardo J.; Burrows, David; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing;

SXI prototype mirror mount

NASA Technical Reports Server (NTRS)

1995-01-01

The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve the design, assembly and alignment of the telescope. Finally, a high level assembly and alignment plan for the entire telescope was prepared by UAH. This plan addresses the sequence of assembly, the required assembly and alignment tolerances, and the methods to verify the alignment at each step during the assembly process. This assembly and alignment plan will be used to assemble and integrate the engineering model (EM) of the telescope. Later on, based on this plan more detailed assembly and alignment procedures will be developed for the lower-level assemblies of SXI.

High-performance mirror for space applications using anodic bonding technology

NASA Astrophysics Data System (ADS)

Otto, W.; Fischer, E.; Kemper, J.; Koch, S.; Kolberg, J.; Kramer, C.; Kunde, J.; Läger, M.

2017-11-01

Berliner Glas developed and manufactured the plane elliptical shaped mirrors for the Synopta Coarse Pointing Assembly (CPA) being one of the key elements of the TESAT Spacecom Laser Communication Terminals (LCT's). The first TESAT LCT containing a Synopta CPA was embarked on Sentinel 1A and is in orbit since April 2014. TESAT Spacecom LCT's have been successfully tested in space since 2007 and are now operationally used in commercial satellite communication systems.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

This photo (rear view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Manufacture, alignment and measurement for a reflective triplet optics in imaging spectrometer

NASA Astrophysics Data System (ADS)

Yuan, Liyin; He, Zhiping; Wang, Yueming; Lv, Gang

2016-09-01

Reflective triplet (RT) optics is an optical form with decenters and tilts of all the three mirrors. It can be used in spectrometer as collimator and reimager to get fine optical and spectral performances. To alleviate thermal and assembly stress deformation, opto-mechanical integrated design suggests that as with all the machine elements and the mainframe, the mirrors substrates are aluminum. All the mirrors are manufactured by single-point diamond turning technology and measured by interferometer or profilometer. Because of retro-reflection by grating or prism and reimaging away from the object field, solo three mirrors optical path of RT has some aberrations. So its alignment and measurement needs an aberration corrected measuring optical system with auxiliary plane and sphere mirrors and in which the RT optics used in four pass. Manufacture, alignment and measurement for a RT optics used in long wave infrared grating spectrometer is discussed here. We realized the manufacture, alignment and test for the RT optics of a longwave infrared spectromter by CMM and interferometer. Wavefront error test by interferometer and surface profiles measured by profilometer indicate that performances of the manufactured mirrors exceed the requirements. Interferogram of the assembled RT optics shows that wavefront error rms is less than 0.0493λ@10.6μm vs design result 0.0207λ.

AMTD: update of engineering specifications derived from science requirements for future UVOIR space telescopes

NASA Astrophysics Data System (ADS)

Stahl, H. Philip; Postman, Marc; Mosier, Gary; Smith, W. Scott; Blaurock, Carl; Ha, Kong; Stark, Christopher C.

2014-08-01

The Advance Mirror Technology Development (AMTD) project is in Phase 2 of a multiyear effort, initiated in FY12, to mature by at least a half TRL step six critical technologies required to enable 4 meter or larger UVOIR space telescope primary mirror assemblies for both general astrophysics and ultra-high contrast observations of exoplanets. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND provide a high-performance low-cost low-risk system. To give the science community options, we are pursuing multiple technology paths. A key task is deriving engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicles and their mass and volume constraints. A key finding of this effort is that the science requires an 8 meter or larger aperture telescope.

AMTD: Update of Engineering Specifications Derived from Science Requirements for Future UVOIR Space Telescopes

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Postman, Marc; Mosier, Gary; Smith, W. Scott; Blaurock, Carl; Ha, Kong; Stark, Christopher C.

2014-01-01

The Advance Mirror Technology Development (AMTD) project is in Phase 2 of a multiyear effort, initiated in FY12, to mature by at least a half TRL step six critical technologies required to enable 4 meter or larger UVOIR space telescope primary mirror assemblies for both general astrophysics and ultra-high contrast observations of exoplanets. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND provide a high-performance low-cost low-risk system. To give the science community options, we are pursuing multiple technology paths. A key task is deriving engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicles and their mass and volume constraints. A key finding of this effort is that the science requires an 8 meter or larger aperture telescope

Electrostatically Driven Large Aperture Micro-Mirror Actuator Assemblies for High Fill-Factor, Agile Optical Phase Arrays

DTIC Science & Technology

2015-06-18

platform assembly 2, with micro-mirror platform deflection, measured on actuation side ( PFa ) and side opposite actuation (PFo...beam micro-mirror platform assembly 1; micro-mirror platform deflection, measured on actuation side ( PFa ) and side opposite actuation (PFo...side ( PFa ) and side opposite actuation (PFo) ........................................................ 106 xiv Figure 73: Graph of measured 10-beam

Current Technology Development Efforts on the International X-Ray Observatory

NASA Technical Reports Server (NTRS)

Robinson, David

2011-01-01

The International X-ray Observatory (IXO) is a collaboration between NASA, ESA, and JAXA which is under study for launch in 2021. IXO will be a large 6600 kilogram Great Observatory-class mission which will build upon the legacies of the Chandra and XMM-Newton X-ray observatories. There is an extensive ongoing effort to raise the technology readiness level of the X-ray mirror from TRL 3 to TRL 6 in the next decade. Improvements have recently been made in the area of positioning and bonding mirrors on the nanometer scale and developing metals and composites with a matching coefficient of thermal expansion to the glass X-ray mirrors. On the mission systems side, the NASA reference design has been through a preliminary coupled loads analysis and a STOP analysis of the flight mirror assembly has been initiated. An impact study was performed comparing launching IXO on an Ariane 5 or a U.S. EELV. This paper will provide a snapshot of NASA's current observatory configuration and summarize the progress of these various technology and design efforts.

Technologies for the fabrication of the E-ELT mirrors within the T-REX project

NASA Astrophysics Data System (ADS)

Pareschi, G.; Aliverti, M.; Bianco, A.; Basso, S.; Citterio, O.; Civitani, M.; Ghigo, M.; Pariani, G.; Sironi, G.; Riva, M.; Vecchi, G.; Zerbi, F.

With its primary mirror with 39 m of diameter, the E-ELT will be the largest optical/near-infrared telescope in the world and will gather 13 times more light than the largest optical telescopes existing today. The different optical sub-systems of E-ELT, including the primary mirror based on hundreds of reflecting tiles assembled together, represent key components for the implementation of the telescopes. A huge amount of aspherical reflecting elements have to be produced with "state of the art" figuring and polishing technologies and measured with proper metrological equipments. In the past couple of years, in the context of the T-REX project, a specific development program was carried out at the Brera Astronomical Observatory-INAF in order to address a numbers of technology aspects related to the fabrication of the E-ELT mirrors. In this paper we give a short overview of the activities that have been carried out. Other papers in this volume report on specific activities that have pursed within such a development program. skip=8pt

Alignment and assembly process for primary mirror subsystem of a spaceborne telescope

NASA Astrophysics Data System (ADS)

Lin, Wei-Cheng; Chang, Shenq-Tsong; Chang, Sheng-Hsiung; Chang, Chen-Peng; Lin, Yu-Chuan; Chin, Chi-Chieh; Pan, Hsu-Pin; Huang, Ting-Ming

2015-11-01

In this study, a multispectral spaceborne Cassegrain telescope was developed. The telescope was equipped with a primary mirror with a 450-mm clear aperture composed of Zerodur and lightweighted at a ratio of approximately 50% to meet both thermal and mass requirements. Reducing the astigmatism was critical for this mirror. The astigmatism is caused by gravity effects, the bonding process, and deformation from mounting the main structure of the telescope (main plate). This article presents the primary mirror alignment, mechanical ground-supported equipment (MGSE), assembly process, and optical performance test used to assemble the primary mirror. A mechanical compensated shim is used as the interface between the bipod flexure and main plate. The shim was used to compensate for manufacturer errors found in components and differences between local coplanarity errors to prevent stress while the bipod flexure was screwed to the main plate. After primary mirror assembly, an optical performance test method called a bench test with an algorithm was used to analyze the astigmatism caused by the gravity effect and deformation from the mounting or supporter. The tolerance conditions for the primary mirror assembly require the astigmatism caused by gravity and mounting force deformation to be less than P-V 0.02 λ at 632.8 nm. The results demonstrated that the designed MGSE used in the alignment and assembly processes met the critical requirements for the primary mirror assembly of the telescope.

First results of the wind evaluation breadboard for ELT primary mirror design

NASA Astrophysics Data System (ADS)

Reyes García-Talavera, Marcos; Viera, Teodora; Núñez, Miguel

2010-07-01

The Wind Evaluation Breadboard (WEB) is a primary mirror and telescope simulator formed by seven aluminium segments, including position sensors, electromechanical support systems and support structures. WEB has been developed to evaluate technologies for primary mirror wavefront control and to evaluate the performance of the control of wind buffeting disturbance on ELT segmented mirrors. For this purpose WEB electro-mechanical set-up simulates the real operational constrains applied to large segmented mirrors. This paper describes the WEB assembly, integration and verification, the instrument characterisation and close loop control design, including the dynamical characterization of the instrument and the control architecture. The performance of the new technologies developed for position sensing, acting and controlling is evaluated. The integration of the instrument in the observatory and the results of the first experiments are summarised, with different wind conditions, elevation and azimuth angles of incidence. Conclusions are extracted with respect the wind rejection performance and the control strategy for an ELT. WEB has been designed and developed by IAC, ESO, ALTRAN and JUPASA, with the integration of subsystems of FOGALE and TNO.

Silicon pore optics for future x-ray telescopes

NASA Astrophysics Data System (ADS)

Wille, Eric; Bavdaz, Marcos; Wallace, Kotska; Shortt, Brian; Collon, Maximilien; Ackermann, Marcelo; Günther, Ramses; Olde Riekerink, Mark; Koelewijn, Arenda; Haneveld, Jeroen; van Baren, Coen; Erhard, Markus; Kampf, Dirk; Christensen, Finn; Krumrey, Michael; Freyberg, Michael; Burwitz, Vadim

2017-11-01

Lightweight X-ray Wolter optics with a high angular resolution will enable the next generation of X-ray telescopes in space. The candidate mission ATHENA (Advanced Telescope for High Energy Astrophysics) required a mirror assembly of 1 m2 effective area (at 1 keV) and an angular resolution of 10 arcsec or better. These specifications can only be achieved with a novel technology like Silicon Pore Optics, which is being developed by ESA together with a consortium of European industry. Silicon Pore Optics are made of commercial Si wafers using process technology adapted from the semiconductor industry. We present the recent upgrades made to the manufacturing processes and equipment, ranging from the manufacture of single mirror plates towards complete focusing mirror modules mounted in flight configuration, and results from first vibration tests. The performance of the mirror modules is tested at X-ray facilities that were recently extended to measure optics at a focal distance up to 20 m.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

This photo (a frontal view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Kodak Mirror Assembly Tested at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

2003-01-01

This photo (a side view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Space Science

NASA Image and Video Library

2003-04-09

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, an MSFC employee is inspecting one of many segments of the mirror assembly for flaws. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Space Science

NASA Image and Video Library

2003-04-09

The Eastman-Kodak mirror assembly is being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). In this photo, one of many segments of the mirror assembly is being set up inside the 24-ft vacuum chamber where it will undergo x-ray calibration tests. MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Completion of the Design of the Top End Optical Assembly for ATST

NASA Astrophysics Data System (ADS)

Canzian, Blaise; Barentine, J.

2013-01-01

L-3 Integrated Optical Systems (IOS) Division has been selected by the National Solar Observatory (NSO) to make the Top End Optical Assembly (TEOA) for the 4-meter Advanced Technology Solar Telescope (ATST) to operate at Haleakala, Maui. ATST will perform to a very high optical performance level in a difficult operational environment. The TEOA (including a 0.65-meter silicon carbide secondary mirror and support, mirror thermal management system, mirror positioning and fast tip-tilt system, field stop with thermally managed heat dump, Lyot stop, safety interlock and control system, and support frame) operates in the “hot spot” at the prime focus of the ATST, presenting unusual challenges. L-3 IOS has passed Critical Design Review of the TEOA. In this paper, we describe L-3 IOS success meeting technical challenges, including our solutions for optic fabrication, opto-mechanical positioning, rejected and stray light control, wavefront tip-tilt compensation, and thermal management and control.

Using the ISS as a testbed to prepare for the next generation of space-based telescopes

NASA Astrophysics Data System (ADS)

Postman, Marc; Sparks, William B.; Liu, Fengchuan; Ess, Kim; Green, Joseph; Carpenter, Kenneth G.; Thronson, Harley; Goullioud, Renaud

2012-09-01

The infrastructure available on the ISS provides a unique opportunity to develop the technologies necessary to assemble large space telescopes. Assembling telescopes in space is a game-changing approach to space astronomy. Using the ISS as a testbed enables a concentration of resources on reducing the technical risks associated with integrating the technologies, such as laser metrology and wavefront sensing and control (WFS&C), with the robotic assembly of major components including very light-weight primary and secondary mirrors and the alignment of the optical elements to a diffraction-limited optical system in space. The capability to assemble the optical system and remove and replace components via the existing ISS robotic systems such as the Special Purpose Dexterous Manipulator (SPDM), or by the ISS Flight Crew, allows for future experimentation as well as repair if necessary. In 2015, first light will be obtained by the Optical Testbed and Integration on ISS eXperiment (OpTIIX), a small 1.5-meter optical telescope assembled on the ISS. The primary objectives of OpTIIX include demonstrating telescope assembly technologies and end-to-end optical system technologies that will advance future large optical telescopes.

Null Lens Assembly for X-Ray Mirror Segments

NASA Technical Reports Server (NTRS)

Robinson, David W.

2011-01-01

A document discusses a null lens assembly that allows laser interferometry of 60 deg. slumped glass mirror segments used in x-ray mirrors. The assembly consists of four lenses in precise alignment to each other, with incorporated piezoelectric nanometer stepping actuators to position the lenses in six degrees of freedom for positioning relative to each other.

Overview and Summary of the Advanced Mirror Technology Development Project

NASA Astrophysics Data System (ADS)

Stahl, H. P.

2014-01-01

Advanced Mirror Technology Development (AMTD) is a NASA Strategic Astrophysics Technology project to mature to TRL-6 the critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable mission can be considered by the 2020 Decadal Review. The developed mirror technology must enable missions capable of both general astrophysics & ultra-high contrast observations of exoplanets. Just as JWST’s architecture was driven by launch vehicle, a future UVOIR mission’s architectures (monolithic, segmented or interferometric) will depend on capacities of future launch vehicles (and budget). Since we cannot predict the future, we must prepare for all potential futures. Therefore, to provide the science community with options, we are pursuing multiple technology paths. AMTD uses a science-driven systems engineering approach. We derived engineering specifications for potential future monolithic or segmented space telescopes based on science needs and implement constraints. And we are maturing six inter-linked critical technologies to enable potential future large aperture UVOIR space telescope: 1) Large-Aperture, Low Areal Density, High Stiffness Mirrors, 2) Support Systems, 3) Mid/High Spatial Frequency Figure Error, 4) Segment Edges, 5) Segment-to-Segment Gap Phasing, and 6) Integrated Model Validation Science Advisory Team and a Systems Engineering Team. We are maturing all six technologies simultaneously because all are required to make a primary mirror assembly (PMA); and, it is the PMA’s on-orbit performance which determines science return. PMA stiffness depends on substrate and support stiffness. Ability to cost-effectively eliminate mid/high spatial figure errors and polishing edges depends on substrate stiffness. On-orbit thermal and mechanical performance depends on substrate stiffness, the coefficient of thermal expansion (CTE) and thermal mass. And, segment-to-segment phasing depends on substrate & structure stiffness. This presentation will introduce the goals and objectives of the AMTD project and summarize its recent accomplishments.

Optical simulations for design, alignment, and performance prediction of silicon pore optics for the ATHENA x-ray telescope (Conference Presentation)

NASA Astrophysics Data System (ADS)

Spiga, D.; Della Monica Ferreira, D.; Shortt, B.; Bavdaz, M.; Bergback Knudsen, E.; Bianucci, G.; Christensen, F.; Civitani, M.; Collon, M.; Conconi, P.; Fransen, S.; Marioni, F.; Massahi, S.; Pareschi, G.; Salmaso, B.; Jegers, A. S.; Tayabaly, K.; Valsecchi, G.; Westergaard, N.; Wille, E.

2017-09-01

The ATHENA X-ray observatory is a large-class ESA approved mission, with launch scheduled in 2028. The technology of silicon pore optics (SPO) was selected as baseline to assemble ATHENA's optic with hundreds of mirror modules, obtained by stacking wedged and ribbed silicon wafer plates onto silicon mandrels to form the Wolter-I configuration. In the current configuration, the optical assembly has a 3 m diameter and a 2 m2 effective area at 1 keV, with a required angular resolution of 5 arcsec. The angular resolution that can be achieved is chiefly the combination of 1) the focal spot size determined by the pore diffraction, 2) the focus degradation caused by surface and profile errors, 3) the aberrations introduced by the misalignments between primary and secondary segments, 4) imperfections in the co-focality of the mirror modules in the optical assembly. A detailed simulation of these aspects is required in order to assess the fabrication and alignment tolerances; moreover, the achievable effective area and angular resolution depend on the mirror module design. Therefore, guaranteeing these optical performances requires: a fast design tool to find the most performing solution in terms of mirror module geometry and population, and an accurate point spread function simulation from local metrology and positioning information. In this paper, we present the results of simulations in the framework of ESA-financed projects (SIMPOSiuM, ASPHEA, SPIRIT), in preparation of the ATHENA X-ray telescope, analyzing the mentioned points: 1) we deal with a detailed description of diffractive effects in an SPO mirror module, 2) we show ray-tracing results including surface and profile defects of the reflective surfaces, 3) we assess the effective area and angular resolution degradation caused by alignment errors between SPO mirror module's segments, and 4) we simulate the effects of co-focality errors in X-rays and in the UV optical bench used to study the mirror module alignment and integration.

Design and Analysis of the International X-Ray Observatory Mirror Modules

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; Carnahan, Timothy M.; Robinson, David W.; Saha, Timo T.

2009-01-01

The Soft X-Ray Telescope (SXT) modules are the fundamental focusing assemblies on NASA's next major X-ray telescope mission, the International X-Ray Observatory (IXO). The preliminary design and analysis of these assemblies has been completed, addressing the major engineering challenges and leading to an understanding of the factors effecting module performance. Each of the 60 modules in the Flight Mirror Assembly (FMA) supports 200-300 densely packed 0.4 mm thick glass mirror segments in order to meet the unprecedented effective area required to achieve the scientific objectives of the mission. Detailed Finite Element Analysis (FEA), materials testing, and environmental testing have been completed to ensure the modules can be successfully launched. Resulting stress margins are positive based on detailed FEA, a large factor of safety, and a design strength determined by robust characterization of the glass properties. FEA correlates well with the results of the successful modal, vibration, and acoustic environmental tests. Deformation of the module due to on-orbit thermal conditions is also a major design driver. A preliminary thermal control system has been designed and the sensitivity of module optical performance to various thermal loads has been determined using optomechanical analysis methods developed for this unique assembly. This design and analysis furthers the goal of building a module that demonstrates the ability to meet IXO requirements, which is the current focus of the IXO FMA technology development team.

Cryogenic Optical Performance of a Light-weight Mirror Assembly for Future Space Astronomical Telescopes: Optical Test Results and Thermal Optical Model

NASA Technical Reports Server (NTRS)

Eng, Ron; Arnold, William; Baker, Markus A.; Bevan, Ryan M.; Carpenter, James R.; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Kegley, Jeffrey R.; Hogue, William D.;

Alignment System for Full-Shell Replicated X-Ray Mirrors

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Arnold, William; Ramsey, Brian

2009-01-01

We are developing grazing-incidence x-ray optics for high-energy astrophysical applications using the electroformnickel replication process. For space-based applications these optics must be light-weight yet stable, which dictates the use of very-thin-walled full-shell mirrors. Such shells have been fabricated with resolution as good as 11 arcsec for hard x-rays, and technology enhancements under development at MSFC are aimed at producing mirrors with resolution better than 10 arcsec. The challenge, however, is to preserve this resolution during mounting and assembly. We present here a status report on a mounting and alignment system currently under development at Marshall Space Flight Center designed to meet this challenge.

Technicians position the transport cradle as a crane lowers SOFIA's primary mirror assembly into place prior to finish coating of the mirror at NASA Ames

NASA Image and Video Library

2008-04-18

Technicians at the NASA Dryden Aircraft Operations Facility in Palmdale, Calif., removed the German-built primary mirror assembly from the Stratospheric Observatory for Infrared Astronomy, or SOFIA, April 18, 2008 in preparation for the final finish coating of the mirror. A precision crane lifted the more than two-ton mirror assembly from its cavity in the rear fuselage of the highly modified Boeing 747SP. The assembly was then secured in its transport dolly and moved to a clean room where it was prepared for shipment to NASA Ames Research Center at Moffett Field near Mountain View, Calif. where it would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

On the alignment and focusing of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)

NASA Astrophysics Data System (ADS)

Champey, Patrick; Winebarger, Amy; Kobayashi, Ken; Savage, Sabrina; Cirtain, Jonathan; Cheimets, Peter; Hertz, Edward; Golub, Leon; Ramsey, Brian; McCracken, Jeff; Marquez, Vanessa; Allured, Ryan; Heilmann, Ralf K.; Schattenburg, Mark; Bruccoleri, Alexander

2016-07-01

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument that is designed to observe soft X-ray emissions from 24 - 6.0 Å (0.5 - 2.0 keV energies) in the solar atmosphere. For the first time, high-temperature, low-emission plasma will be observed directly with 5 arcsecond spatial resolution and 22 mÅ spectral resolution. The unique optical design consists of a Wolter - I telescope and a 3-optic grazing- incidence spectrometer. The spectrometer utilizes a finite conjugate mirror pair and a blazed planar, varied line spaced grating, which is directly printed on a silicon substrate using e-beam lithography. The grating design is being finalized and the grating will be fabricated by the Massachusetts Institute of Technology (MIT) and Izentis LLC. Marshall Space Flight Center (MSFC) is producing the nickel replicated telescope and spectrometer mirrors using the same facilities and techniques as those developed for the ART-XC and FOXSI mirrors. The Smithsonian Astrophysical Observatory (SAO) will mount and align the optical sub-assemblies based on previous experience with similar instruments, such as the Hinode X-Ray Telescope (XRT). The telescope and spectrometer assembly will be aligned in visible light through the implementation of a theodolite and reference mirrors, in addition to the centroid detector assembly (CDA) - a device designed to align the AXAF-I nested mirrors. Focusing of the telescope and spectrometer will be achieved using the X-ray source in the Stray Light Facility (SLF) at MSFC. We present results from an alignment sensitivity analysis performed on the on the system and we also discuss the method for aligning and focusing MaGIXS.

On the Alignment and Focusing of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)

NASA Technical Reports Server (NTRS)

Champey, Patrick; Winebarger, Amy; Kobayashi, Ken; Savage, Sabrina; Cirtain, Jonathan; Cheimets, Peter; Hertz, Edward; Golub, Leon; Ramsey, Brian; McCracken, Jeff

2016-01-01

The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument that is designed to observe soft X-ray emissions from 24 - 6.0 A (0.5 - 2.0 keV energies) in the solar atmosphere. For the rst time, high-temperature, low-emission plasma will be observed directly with 5 arcsecond spatial resolution and 22 mA spectral resolution. The unique optical design consists of a Wolter - I telescope and a 3-optic grazing- incidence spectrometer. The spectrometer utilizes a nite conjugate mirror pair and a blazed planar, varied line spaced grating, which is directly printed on a silicon substrate using e-beam lithography. The grating design is being nalized and the grating will be fabricated by the Massachusetts Institute of Technology (MIT) and Izentis LLC. Marshall Space Flight Center (MSFC) is producing the nickel replicated telescope and spectrometer mirrors using the same facilities and techniques as those developed for the ART-XC and FOXSI mirrors. The Smithsonian Astrophysical Observatory (SAO) will mount and align the optical sub-assemblies based on previous experience with similar instruments, such as the Hinode X-Ray Telescope (XRT). The telescope and spectrometer assembly will be aligned in visible light through the implementation of a theodolite and reference mirrors, in addition to the centroid detector assembly (CDA) { a device designed to align the AXAF-I nested mirrors. Focusing of the telescope and spectrometer will be achieved using the X-ray source in the Stray Light Facility (SLF) at MSFC. We present results from an alignment sensitivity analysis performed on the on the system and we also discuss the method for aligning and focusing MaGIXS.

Lightweight deformable mirrors for future space telescopes

NASA Astrophysics Data System (ADS)

Patterson, Keith

This thesis presents a concept for ultra-lightweight deformable mirrors based on a thin substrate of optical surface quality coated with continuous active piezopolymer layers that provide modes of actuation and shape correction. This concept eliminates any kind of stiff backing structure for the mirror surface and exploits micro-fabrication technologies to provide a tight integration of the active materials into the mirror structure, to avoid actuator print-through effects. Proof-of-concept, 10-cm-diameter mirrors with a low areal density of about 0.5 kg/m2 have been designed, built and tested to measure their shape-correction performance and verify the models used for design. The low cost manufacturing scheme uses replication techniques, and strives for minimizing residual stresses that deviate the optical figure from the master mandrel. It does not require precision tolerancing, is lightweight, and is therefore potentially scalable to larger diameters for use in large, modular space telescopes. Other potential applications for such a laminate could include ground-based mirrors for solar energy collection, adaptive optics for atmospheric turbulence, laser communications, and other shape control applications. The immediate application for these mirrors is for the Autonomous Assembly and Reconfiguration of a Space Telescope (AAReST) mission, which is a university mission under development by Caltech, the University of Surrey, and JPL. The design concept, fabrication methodology, material behaviors and measurements, mirror modeling, mounting and control electronics design, shape control experiments, predictive performance analysis, and remaining challenges are presented herein. The experiments have validated numerical models of the mirror, and the mirror models have been used within a model of the telescope in order to predict the optical performance. A demonstration of this mirror concept, along with other new telescope technologies, is planned to take place during the AAReST mission.

Realization and testing of a deployable space telescope based on tape springs

NASA Astrophysics Data System (ADS)

Lei, Wang; Li, Chuang; Zhong, Peifeng; Chong, Yaqin; Jing, Nan

2017-08-01

For its compact size and light weight, space telescope with deployable support structure for its secondary mirror is very suitable as an optical payload for a nanosatellite or a cubesat. Firstly the realization of a prototype deployable space telescope based on tape springs is introduced in this paper. The deployable telescope is composed of primary mirror assembly, secondary mirror assembly, 6 foldable tape springs to support the secondary mirror assembly, deployable baffle, aft optic components, and a set of lock-released devices based on shape memory alloy, etc. Then the deployment errors of the secondary mirror are measured with three-coordinate measuring machine to examine the alignment accuracy between the primary mirror and the deployed secondary mirror. Finally modal identification is completed for the telescope in deployment state to investigate its dynamic behavior with impact hammer testing. The results of the experimental modal identification agree with those from finite element analysis well.

Toward Large-Area Sub-Arcsecond X-Ray Telescopes

NASA Technical Reports Server (NTRS)

ODell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.;

Toward Large-Area Sub-Arcsecond X-Ray Telescopes

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.;

Mounting for Fabrication, Metrology, and Assembly of Full Shell Grazing Incidence Optics

NASA Technical Reports Server (NTRS)

Roche, Jacqueline M.; Gubarev, Mikhail V.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Ramsey, Brian D.; Elsner, Ronald F.

2014-01-01

Future x-ray telescopes will likely require lightweight mirrors to attain the large collecting areas needed to accomplish the science objectives. Understanding and demonstrating processes now is critical to achieving sub-arcsecond performance in the future. Consequently, designs not only of the mirrors but of fixtures for supporting them during fabrication, metrology, handling, assembly, and testing must be adequately modeled and verified. To this end, MSFC is using finite-element modeling to study the effects of mounting on full-shell grazing-incidence mirrors, during all processes leading to flight mirror assemblies. Here we report initial results of this study.

Dynamic analysis of the large deployable reflector

NASA Technical Reports Server (NTRS)

Calleson, Robert E.; Scott, A. Don

1987-01-01

The Large Deployable Reflector (LDR) is to be an astronomical observatory orbiting above Earth's obscuring atmosphere and operating in the spectral range between 30 microns and 1000 microns wavelength. The LDR will be used to study such astronomical phenomena as stellar and galactic formation, cosmology, and planetary atmospheres. The LDR will be the first observatory to be erected and assembled in space. This distinction brings with it several major technological challenges such as the development of ultra-lightweight deployable mirrors, advanced mirror fabrication techniques, advanced structures, and control of vibrations due to various sources of excitation. The purpose of this analysis is to provide an assessment of the vibrational response due to secondary mirror chopping and LDR slewing. The dynamic response of two 20-m LDR configurations was studied. Two mirror support configurations were investigated for the Ames concept, the first employs a six-strut secondary mirror support structure, while the second uses a triple-bipod support design. All three configurations were modeled using a tetrahedral truss design for the primary mirror support structure. Response resulting from secondary mirror chopping was obtained for the two Ames configurations, and the response of the primary mirror from slewing was obtained for all three configurations.

Prototype Development of the GMT Fast Steering Mirror

NASA Astrophysics Data System (ADS)

Kim, Young-Soo; Koh, J.; Jung, H.; Jung, H.; Cho, M. K.; Park, W.; Yang, H.; Kim, H.; Lee, K.; Ahn, H.; Park, B.

2013-06-01

A Fast Steering Mirror (FSM) is going to be produced as a secondary mirror of the Giant Magellan Telescope (GMT). FSM is 3.2 m in diameter and the focal ratio is 0.65. It is composed of seven circular segments which match with the primary mirror segments. Each segment contains a light-weighted mirror whose diameter is 1.1 m. It also contains tip-tilt actuators which would compensate wind effect and structure jitter. An FSM prototype (FSMP) has been developed, which consists of a full-size off-axis mirror segment and a tip-tilt test-bed. The main purpose of the FSMP development is to achieve key technologies, such as fabrication of highly aspheric off-axis mirror and tip-tilt actuation. The development has been conducted by a consortium of five institutions in Korea and USA, and led by Korea Astronomy and Space Science Institute. The mirror was light-weighted and grinding of the front surface was finished. Polishing is in progress with computer generated hologram tests. The tip-tilt test-bed has been manufactured and assembled. Frequency tests are being performed and optical tilt set-up is arranged for visual demonstration. In this paper, we present progress of the prototype development, and future works.

Status of the eROSITA Telescope testing and calibrating the x-ray mirror assemblies

NASA Astrophysics Data System (ADS)

Burwitz, Vadim; Predehl, Peter; Bräuninger, Heinrich; Burkert, Wolfgang; Dennerl, Konrad; Eder, Josef; Friedrich, Peter; Fürmetz, Maria; Grisoni, Gabriele; Hartner, Gisela; Marioni, Fabio; Menz, Benedikt; Pfeffermann, Elmar; Valsecchi, Giuseppe

2013-09-01

The eROSITA X-ray observatory that will be launched on board the Russian Spectrum-RG mission comprises seven X-ray telescopes, each with its own mirror assembly (mirror module + X-ray baffle), electron deflector, filter wheel, and CCD camera with its control electronics. The completed flight mirror modules are undergoing many thorough X-ray tests at the PANTHER X-ray test facility after delivery, after being mated with the X-ray baffle, and again after both the vibration and thermal-vacuum tests. A description of the work done with mirror modules/assemblies and the test results obtained will be reported here. We report also on the environmental tests that have been performed on the eROSITA telescope qualification model.

A NASA Technician directs loading of the crated SOFIA primary mirror assembly into a C-17 for shipment to NASA Ames Research Center for finish coating

NASA Image and Video Library

2008-05-01

Technicians at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., loaded the German-built primary mirror assembly of the Stratospheric Observatory for Infrared Astronomy, or SOFIA, onto an Air Force C-17 for shipment to NASA's Ames Research Center on May 1, 2008. In preparation for the final finish coating of the mirror, the more than two-ton mirror assembly had been removed from its cavity in the rear fuselage of the highly modified SOFIA Boeing 747SP two weeks earlier. After arrival at NASA Ames at Moffett Field near Mountain View, Calif., the mirror would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

Maximizing coupling-efficiency of high-power diode lasers utilizing hybrid assembly technology

NASA Astrophysics Data System (ADS)

Zontar, D.; Dogan, M.; Fulghum, S.; Müller, T.; Haag, S.; Brecher, C.

2015-03-01

In this paper, we present hybrid assembly technology to maximize coupling efficiency for spatially combined laser systems. High quality components, such as center-turned focusing units, as well as suitable assembly strategies are necessary to obtain highest possible output ratios. Alignment strategies are challenging tasks due to their complexity and sensitivity. Especially in low-volume production fully automated systems are economically at a disadvantage, as operator experience is often expensive. However reproducibility and quality of automatically assembled systems can be superior. Therefore automated and manual assembly techniques are combined to obtain high coupling efficiency while preserving maximum flexibility. The paper will describe necessary equipment and software to enable hybrid assembly processes. Micromanipulator technology with high step-resolution and six degrees of freedom provide a large number of possible evaluation points. Automated algorithms are necess ary to speed-up data gathering and alignment to efficiently utilize available granularity for manual assembly processes. Furthermore, an engineering environment is presented to enable rapid prototyping of automation tasks with simultaneous data ev aluation. Integration with simulation environments, e.g. Zemax, allows the verification of assembly strategies in advance. Data driven decision making ensures constant high quality, documents the assembly process and is a basis for further improvement. The hybrid assembly technology has been applied on several applications for efficiencies above 80% and will be discussed in this paper. High level coupling efficiency has been achieved with minimized assembly as a result of semi-automated alignment. This paper will focus on hybrid automation for optimizing and attaching turning mirrors and collimation lenses.

Towards a Multi-Variable Parametric Cost Model for Ground and Space Telescopes

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Henrichs, Todd

2016-01-01

Parametric cost models can be used by designers and project managers to perform relative cost comparisons between major architectural cost drivers and allow high-level design trades; enable cost-benefit analysis for technology development investment; and, provide a basis for estimating total project cost between related concepts. This paper hypothesizes a single model, based on published models and engineering intuition, for both ground and space telescopes: OTA Cost approximately (X) D(exp (1.75 +/- 0.05)) lambda(exp(-0.5 +/- 0.25) T(exp -0.25) e (exp (-0.04)Y). Specific findings include: space telescopes cost 50X to 100X more ground telescopes; diameter is the most important CER; cost is reduced by approximately 50% every 20 years (presumably because of technology advance and process improvements); and, for space telescopes, cost associated with wavelength performance is balanced by cost associated with operating temperature. Finally, duplication only reduces cost for the manufacture of identical systems (i.e. multiple aperture sparse arrays or interferometers). And, while duplication does reduce the cost of manufacturing the mirrors of segmented primary mirror, this cost savings does not appear to manifest itself in the final primary mirror assembly (presumably because the structure for a segmented mirror is more complicated than for a monolithic mirror).

Multivariable parametric cost model for space and ground telescopes

NASA Astrophysics Data System (ADS)

Stahl, H. Philip; Henrichs, Todd

2016-09-01

Parametric cost models can be used by designers and project managers to perform relative cost comparisons between major architectural cost drivers and allow high-level design trades; enable cost-benefit analysis for technology development investment; and, provide a basis for estimating total project cost between related concepts. This paper hypothesizes a single model, based on published models and engineering intuition, for both ground and space telescopes: OTA Cost (X) D (1.75 +/- 0.05) λ (-0.5 +/- 0.25) T-0.25 e (-0.04) Y Specific findings include: space telescopes cost 50X to 100X more ground telescopes; diameter is the most important CER; cost is reduced by approximately 50% every 20 years (presumably because of technology advance and process improvements); and, for space telescopes, cost associated with wavelength performance is balanced by cost associated with operating temperature. Finally, duplication only reduces cost for the manufacture of identical systems (i.e. multiple aperture sparse arrays or interferometers). And, while duplication does reduce the cost of manufacturing the mirrors of segmented primary mirror, this cost savings does not appear to manifest itself in the final primary mirror assembly (presumably because the structure for a segmented mirror is more complicated than for a monolithic mirror).

SiC lightweight telescopes for advanced space applications. II - Structures technology

NASA Technical Reports Server (NTRS)

Anapol, Michael I.; Hadfield, Peter; Tucker, Theodore

1992-01-01

A critical technology area for lightweight SiC-based telescope systems is the structural integrity and thermal stability over spaceborne environmental launch and thermal operating conditions. Note, it is highly desirable to have an inherently athermal design of both SiC mirrors and structure. SSG has developed an 8 inch diameter SiC telescope system for brassboard level optical and thermal testing. The brassboard telescope has demonstrated less than 0.2 waves P-V in the visible wavefront change over +50 C to -200 C temperature range. SSG has also fabricated a SiC truss structural assembly and successfully qualified this hardware at environmental levels greater than 3 times higher than normal Delta, Titan, and ARIES launch loads. SSG is currently developing two SiC telescopes; an 20 cm diameter off-axis 3 mirror re-imaging and a 60 cm aperture on-axis 3 mirror re-imager. Both hardware developments will be tested to flight level environmental, optical, and thermal specifications.

OpTIIX: An ISS-Based Testbed Paving the Roadmap Toward a Next Generation Large Aperture UV/Optical Space Telescope

NASA Technical Reports Server (NTRS)

Carpenter, Kenneth G.; Etemad, Shar; Seery, Bernard D.; Thronson, Harley; Burdick, Gary M.; Coulter, Dan; Goullioud, Renaud; Green, Joseph J.; Liu, Fengchuan; Ess, Kim;

SOFIA's primary mirror assembly is cradled on its dolly as technicians prepare to move it into a "clean room" at NASA Dryden's Aircraft Operations Facility

NASA Image and Video Library

2008-04-18

Technicians at the NASA Dryden Aircraft Operations Facility in Palmdale, Calif., removed the German-built primary mirror assembly from the Stratospheric Observatory for Infrared Astronomy, or SOFIA, April 18, 2008 in preparation for the final finish coating of the mirror. A precision crane lifted the more than two-ton mirror assembly from its cavity in the rear fuselage of the highly modified Boeing 747SP. The assembly was then secured in its transport dolly and moved to a clean room where it was prepared for shipment to NASA Ames Research Center at Moffett Field near Mountain View, Calif. where it would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

The SOFIA primary mirror assembly is cautiously lifted from its cavity in the modified 747 by a crane in preparation for finish coating operations at NASA Ames

NASA Image and Video Library

2008-04-18

Technicians at the NASA Dryden Aircraft Operations Facility in Palmdale, Calif., removed the German-built primary mirror assembly from the Stratospheric Observatory for Infrared Astronomy, or SOFIA, April 18, 2008 in preparation for the final finish coating of the mirror. A precision crane lifted the more than two-ton mirror assembly from its cavity in the rear fuselage of the highly modified Boeing 747SP. The assembly was then secured in its transport dolly and moved to a clean room where it was prepared for shipment to NASA Ames Research Center at Moffett Field near Mountain View, Calif. where it would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

Technicians carefully guide SOFIA's primary mirror assembly on its transport cradle into a clean room where it is being prepared for shipment to NASA Ames

NASA Image and Video Library

2008-04-18

Technicians at the NASA Dryden Aircraft Operations Facility in Palmdale, Calif., removed the German-built primary mirror assembly from the Stratospheric Observatory for Infrared Astronomy, or SOFIA, April 18, 2008 in preparation for the final finish coating of the mirror. A precision crane lifted the more than two-ton mirror assembly from its cavity in the rear fuselage of the highly modified Boeing 747SP. The assembly was then secured in its transport dolly and moved to a clean room where it was prepared for shipment to NASA Ames Research Center at Moffett Field near Mountain View, Calif. where it would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

Technicians with ropes carefully guide the primary mirror assembly as a crane slowly moves it toward its transport cradle after removal from the SOFIA aircraft

NASA Image and Video Library

2008-04-18

Technicians at the NASA Dryden Aircraft Operations Facility in Palmdale, Calif., removed the German-built primary mirror assembly from the Stratospheric Observatory for Infrared Astronomy, or SOFIA, April 18, 2008 in preparation for the final finish coating of the mirror. A precision crane lifted the more than two-ton mirror assembly from its cavity in the rear fuselage of the highly modified Boeing 747SP. The assembly was then secured in its transport dolly and moved to a clean room where it was prepared for shipment to NASA Ames Research Center at Moffett Field near Mountain View, Calif. where it would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

The Alignment Test System for AXAF-I's High Resolution Mirror Assembly

NASA Technical Reports Server (NTRS)

Waldman, Mark

1995-01-01

The AXAF-1 High Resolution Mirror Assembly (HRMA) consists of four nested mirror pairs of Wolter Type-1 grazing incidence optics. The HRMA assembly and alignment will take place in a vibration-isolated, cleanliness class 100, 18 meter high tower at an Eastman Kodak Company facility in Rochester, NY. Each mirror pair must be aligned such that its image is coma-free, and the four pairs must be aligned such that their images are coincident. In addition, both the HRMA optical axis and focal point must be precisely known with respect to physical references on the HRMA. The alignment of the HRMA mirrors is measured by the HRMA Alignment Test System (HATS), which is an integral part of the tower facility. The HATS is configured as a double-pass, autocollimating Hartmann test where each mirror aperture is scanned to determine the state of alignment. This paper will describe the design and operation of the HATS.

HabEx Optical Telescope Assembly

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2017-01-01

Purpose: a) Introduce candidate optical telescope assembly (OTA) architectures. b) Illustrate design/analysis process. Agenda: a) Definitions, Specification & Assumptions. b.) 4-meter Monolithic Mirror Concept. c) 6.5-meter Segmented Mirror Concept.

Ground crewmen prepare to load the crated SOFIA primary mirror assembly into an Air Force C-17 for shipment to NASA Ames Research Center for finish coating

NASA Image and Video Library

2008-05-01

Technicians at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., loaded the German-built primary mirror assembly of the Stratospheric Observatory for Infrared Astronomy, or SOFIA, onto an Air Force C-17 for shipment to NASA's Ames Research Center on May 1, 2008. In preparation for the final finish coating of the mirror, the more than two-ton mirror assembly had been removed from its cavity in the rear fuselage of the highly modified SOFIA Boeing 747SP two weeks earlier. After arrival at NASA Ames at Moffett Field near Mountain View, Calif., the mirror would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

Ground crewmen shove the more than two-ton SOFIA primary mirror assembly in its transport crate into a C-17's cavernous cargo bay for shipment to NASA Ames

NASA Image and Video Library

2008-05-01

Technicians at NASA's Dryden Aircraft Operations Facility in Palmdale, Calif., loaded the German-built primary mirror assembly of the Stratospheric Observatory for Infrared Astronomy, or SOFIA, onto an Air Force C-17 for shipment to NASA's Ames Research Center on May 1, 2008. In preparation for the final finish coating of the mirror, the more than two-ton mirror assembly had been removed from its cavity in the rear fuselage of the highly modified SOFIA Boeing 747SP two weeks earlier. After arrival at NASA Ames at Moffett Field near Mountain View, Calif., the mirror would receive its aluminized finish coating before being re-installed in the SOFIA aircraft.

SMART-X: Square Meter, Arcsecond Resolution Telescope for X-rays

NASA Astrophysics Data System (ADS)

Vikhlinin, Alexey; SMART-X Collaboration

2013-04-01

SMART-X is a concept for a next-generation X-ray observatory with large-area, 0.5" angular resolution grazing incidence adjustable X-ray mirrors, high-throughput critical angle transmission gratings, and X-ray microcalorimeter and CMOS-based imager in the focal plane. High angular resolution is enabled by new technology based on controlling the shape of mirror segments using thin film piezo actuators deposited on the back surface. Science applications include observations of growth of supermassive black holes since redshifts of ~10, ultra-deep surveys over 10's of square degrees, galaxy assembly at z=2-3, as well as new opportunities in the high-resolution X-ray spectroscopy and time domains. We also review the progress in technology development, tests, and mission design over the past year.

Method of Analysis for Determining and Correcting Mirror Deformation due to Gravity

DTIC Science & Technology

2014-01-01

obtainable. 1.3 Description of As-Built Beam Compressor Assembly The as-built beam compressor assembly consists of primary and secondary Zerodur ® mirrors held...Method of analysis for determining and correcting mirror deformation due to gravity James H. Clark, III F. Ernesto, Penado Downloaded From: http...00-00-2014 4. TITLE AND SUBTITLE Method of analysis for determining and correcting mirror deformation due to gravity 5a. CONTRACT NUMBER 5b. GRANT

Performance of The Far Ultraviolet Spectroscopic Explorer Mirror Assemblies

NASA Technical Reports Server (NTRS)

Ohi, Raymond G.; Barkhouser, Robert H.; Conard, Steven J.; Friedman, Scott D.; Hampton, Jeffery; Moos, H. Warren; Nikulla, Paul; Oliveira, Cristina M.; Saha, Timo T.; Obenschain, Arthur (Technical Monitor)

2000-01-01

The Far Ultraviolet Spectroscopic Explorer is a NASA astrophysics satellite which produces high-resolution spectra in the far-ultraviolet (90.5-118.7 nm bandpass) using a high effective area and low background detectors. The observatory was launched on its three-year mission from Cape Canaveral Air Station on 24 June 1999. The instrument contains four coaligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographically ruled diffraction gratings and delay line microchannel plate detectors. The telescope mirrors have a 352 x 387 mm aperture and 2245 mm focal length and are attached to actuator assemblies, which provide on-orbit, tip, tilt, and focus control. Two mirrors are coated with silicon carbide (SiC) and two are coated with lithium fluoride over aluminum (Al:LiF). We describe mirror assembly in-flight optical and mechanical performance. On-orbit measurements of the far-ultraviolet point spread function associated with each mirror are compared to expectations based on pre-flight laboratory measurements and modeling using the Optical Surface Analysis Code and surface metrology data. On-orbit imaging data indicate that the mirrors meet their instrument-level requirement of 50 percent and 95 percent slit transmission for the high- and mid-resolution spectrograph entrance slits, respectively. The degradation of mirror reflectivity during satellite integration and test is also discussed. The far-ultraviolet reflectivity of the SiC- and AlLiF-coated mirrors decreased about six percent and three percent, respectively, between coating and launch. Each mirror is equipped with three actuators, which consist of a stepper motor driving a ball screw via a two-stage planetary gear train. We also discuss the mechanical performance of the mirror assemblies, including actuator performance and thermal effects.

Performance of the Far Ultraviolet Spectroscopic Explorer mirror assemblies

NASA Astrophysics Data System (ADS)

Ohl, Raymond G.; Barkhouser, Robert H.; Conard, Steven J.; Friedman, Scott D.; Hampton, Jeffrey; Moos, H. Warren; Nikulla, Paul; Oliveira, Cristina M.; Saha, Timo T.

2000-12-01

The Far Ultraviolet Spectroscopic Explorer is a NASA astrophysics satellite which produces high-resolution spectra in the far-ultraviolet (90.5 - 118.7 nm bandpass) using a high effective area and low background detectors. The observatory was launched on its three-year mission from Cape Canaveral Air Station on 24 June 1999. The instrument contains four co- aligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographically ruled diffraction gratings and delay line microchannel plate detectors. The telescope mirrors have a 352 X 387 mm aperture and 2245 mm focal length and are attached to actuator assemblies, which provide on-orbit, tip, tilt, and focus control. Two mirrors are coated with silicon carbide (SiC) and two are coated with lithium fluoride over aluminum (Al:LiF). We describe mirror assembly in-flight optical and mechanical performance. On-orbit measurements of the far-ultraviolet point spread function associated with each mirror are compared to expectations based on pre-flight laboratory measurements and modeling using the Optical Surface Analysis Code and surface metrology data. On-orbit imaging data indicate that the mirrors meet their instrument-level requirement of 50% and 95% slit transmission for the high- and mid-resolution spectrograph entrance slits, respectively. The degradation of mirror reflectivity during satellite integration and test is also discussed. The FUV reflectivity of the SiC- and Al:LiF-coated mirrors decreased about 6% and 3%, respectively, between coating and launch. Each mirror is equipped with three actuators, which consist of a stepper motor driving a ball screw via a two-stage planetary gear train. We also discuss the mechanical performance of the mirror assemblies, including actuator performance and thermal effects.

Cryogenic Optical Performance of a Lightweighted Mirror Assembly for Future Space Astronomical Telescopes: Correlating Optical Test Results and Thermal Optical Model

NASA Technical Reports Server (NTRS)

Eng, Ron; Arnold, William R.; Baker, Marcus A.; Bevan, Ryan M.; Burdick, Gregory; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Hanson, Craig; Hogue, William D.;

Prototype Development of the GMT Fast Steering Mirror

NASA Astrophysics Data System (ADS)

Kim, Young-Soo; Koh, J.; Jung, H.; Jung, H.; Cho, M. K.; Park, W.; Yang, H.; Kim, H.; Lee, K.; Ahn, H.; Park, B.

2014-01-01

A Fast Steering Mirror (FSM) is going to be provided as the secondary of the Giant Magellan Telescope (GMT) for the first light observations. FSM is 3.2 m in diameter and the focal ratio is 0.65. It is composed of seven circular segments which match with the primary mirror segments. Each segment contains a light-weighted mirror whose diameter is 1.1 m, and each mirror is activated by three tip-tilt actuators which compensate image degradations caused by winds and structure jitter. An FSM prototype (FSMP) has been developed to achieve the key technologies, fabrication of highly aspheric off-axis mirror and precise tip-tilt actuation. It consists of a full-size off-axis mirror segment and a tip-tilt test-bed. The development has been conducted by Korea Astronomy and Space Science Institute together with four other institutions in Korea and USA. The mirror was light-weighted by digging about a hundred holes at the backside, and the front surface has been polished. The result of computer generated hologram measurements showed the surface error of 11.7 nm rms. The tip-tilt test-bed has been manufactured and assembled. Tip-tilt range and resolution tests complied the requirements, and the attenuation test results also satisfied the performance requirements. In this paper, we present the successful developments of the prototype.

Development of a miniature multiple reference optical coherence tomography imaging device

NASA Astrophysics Data System (ADS)

McNamara, Paul M.; O'Riordan, Colm; Collins, Seán.; O'Brien, Peter; Wilson, Carol; Hogan, Josh; Leahy, Martin J.

2016-03-01

Multiple reference optical coherence tomography (MR-OCT) is a new technology ideally suited to low-cost, compact OCT imaging. This modality is an extension of time-domain OCT with the addition of a partial mirror in front of the reference mirror. This enables extended, simultaneous depth scanning with the relatively short sweep of a miniature voice coil motor on which the scanning mirror is mounted. Applications of this technology include biometric security, ophthalmology, personal health monitoring and non-destructive testing. This work details early-stage development of the first iteration of a miniature MR-OCT device. This device utilizes a fiber-coupled input from an off-board superluminescent diode (SLD). Typical dimensions of the module are 40 × 57 mm, but future designs are expected to be more compact. Off-the-shelf miniature optical components, voice coil motors and photodetectors are used, with the complexity of design depending on specific applications. The photonic module can be configured as either polarized or non-polarized and can include balanced detection. The photodetectors are directly connected to a printed circuit board under the module containing a transimpedance amplifier with complimentary outputs. The results shown in this work are from the non-polarized device. Assembly of the photonic modules requires extensive planning. In choosing the optical components, Zemax simulations are performed to model the beam characteristics. The physical layout is modeled using Solidworks and each component is placed and aligned via a well-designed alignment procedure involving an active-alignment pick-and-place assembly system.

Poly-SiGe MEMS actuators for adaptive optics

NASA Astrophysics Data System (ADS)

Lin, Blake C.; King, Tsu-Jae; Muller, Richard S.

2006-01-01

Many adaptive optics (AO) applications require mirror arrays with hundreds to thousands of segments, necessitating a CMOS-compatible MEMS process to integrate the mirrors with their driving electronics. This paper proposes a MEMS actuator that is fabricated using low-temperature polycrystalline silicon-germanium (poly-SiGe) surface-micromaching technology (total thermal budget is 6 hours at or below 425°C). The MEMS actuator consists of three flexures and a hexagonal platform, on which a micromirror is to be assembled. The flexures are made of single-layer poly-SiGe with stress gradient across thickness of the film, making them bend out-of-plane after sacrificial-layer release to create a large nominal gap. The platform, on the other hand, has an additional stress-balancing SiGe layer deposited on top, making the dual-layer stack stay flat after release. Using this process, we have successfully fabricated the MEMS actuator which is lifted 14.6 μm out-of-plane by 290-μm-long flexures. The 2-μm-thick hexagonal mirror-platform exhibits a strain gradient of -5.5×10 -5 μm -1 (equivalent to 18 mm radius-of-curvature), which would be further reduced once the micromirror is assembled.

Chandra X-Ray Observatory High Resolution Mirror Assembly

NASA Technical Reports Server (NTRS)

1997-01-01

This photograph shows the mirrors of the High Resolution Mirror Assembly (HRMA) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being assembled in the Eastman Kodak Company in Rochester, New York. The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical 'telescope' portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission.

A Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST)

NASA Astrophysics Data System (ADS)

Conti, Alberto; Arenberg, Jonathan; Baldauf, Brian

2017-01-01

The “Search for Life” (direct imaging of earth-like planets) will require extremely stable telescopes with apertures in the 10 m to 20 m range. Such apertures are larger than what can be delivered to space using current or planned future launch vehicles. Building and assembling large telescopes in space is therefore likely to require not only multiple launches but importantly assembly in spce. As a result, space-based telescopes with large apertures will require major changes to our conventional telescope design and architecture.Here we report on the concept for the Modular Orbital Demonstration of an Evolvable Space Telescope (MODEST) to demonstrates the on-orbit robotic and/or astronaut assembly of an optical telescope in space. MODEST is a proposed International Space Station (ISS demonstration that will make use of the standard Express Logistics Carriers (ELCs) and can mounted to one of a variety of ISS pallets.MODEST will provides significant risk reduction for the next generation of space observatories, and demonstrates the technology needed to assemble a six-mirror phased telescope. Key modest features include the use of an active primary optical surface with wavefront feedback control to allow on-orbit optimization, and the precise surface control to meet optical system wavefront and stability requirements.MODEST will also be used to evaluate advances in lightweight mirror and metering structure materials such as SiC or Carbon Fiber Reinforced Polymer (CFRP) that have excellent mechanical and thermal properties, e.g. high stiffness, high modulus, high thermal conductivity, and low thermal expansion. Mirrors built from these materials can be rapidly replicated in a highly cost effective manner, making them an excellent candidate for a low cost, high performance Optical Telescope Assembly paving the way for enabling affordable solutions for the next generation of large aperture space-based telescope.MODEST post-assembly value includes space, ground, and environmental studies, a testbed for new instruments, and a tool for student’s exploration of space.

WFXT Technology Overview

NASA Astrophysics Data System (ADS)

Pareschi, G.; Campana, S.

The Wide Field X-ray Telescope (WFXT) is a medium class mission for X-ray surveys of the sky with an unprecedented area and sensitivity. In order to meet the effective area requirement, the design of the optical system is based on very thin mirror shells, with thicknesses in the 1-2 mm range. In order to get the desired angular resolution (10 arcsec requirement, 5 arcsec goal) across the entire 1× 1 degree FOV (Field Of View), the design of the optical system is based on nested modified grazing incidence Wolter-I mirrors realized with polynomial profiles, focal plane curvature and plate scale corrections. This design guarantees an increased angular resolution at large off-axis angle with respect to the normally used Wolter I configuration, making WFXT ideal for survey purposes. The WFXT X-ray Telescope Assembly is composed by three identical mirror modules of 78 nested shells each, with diameter up to 1.1 m. The epoxy replication process with SiC shells has already been proved to be a valuable technology to meet the angular resolution requirement of 10 arcsec. To further mature the telescope manufacturing technology and to achieve the goal of 5 arcsec, we are considering different materials for the mirror shells with particular care to quartz glass (fused silica), a well-known material with good thermo-mechanical and polishability characteristics that could meet our goal in terms of mass and stiffness, with significant cost and time saving with respect to SiC. To bring the mirror shells to the needed accuracy a deterministic direct polishing method for the mirror shells is under investigation. A direct polishing method has already been used for past missions (as Einstein, Rosat, Chandra): the technological challenge now is to apply it for almost ten times thinner shells. Our approach is based on two main steps: first quartz glass tubes available on the market are grinded to conical profiles, and second the obtained shells are polished to the required polynomial profiles by Computer Numerical Control (CNC) polishing machine.

Fabrication and Metrology of High-Precision Foil Mirror Mounting Elements

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2002-01-01

During the period of this Cooperative Agreement, MIT (Massachusetts Institute of Technology) developed advanced methods for applying silicon microstructures for the precision assembly of foil x-ray optics in support of the Constellation-X Spectroscopy X-ray Telescope (SXT) development effort at Goddard Space Flight Center (GSFC). MIT developed improved methods for fabricating and characterizing the precision silicon micro-combs. MIT also developed and characterized assembly tools and several types of metrology tools in order to characterize and reduce the errors associated with precision assembly of foil optics. Results of this effort were published and presented to the scientific community and the GSFC SXT team. A bibliography of papers and presentations is offered.

Ion-assisted coating for large-scale Bimorph deformable mirror

NASA Astrophysics Data System (ADS)

Mikami, Takuya; Okamoto, Takayuki; Yoshida, Kunio; Jitsuno, Takahisa; Motokoshi, Shinji; Samarkin, Vadim V.; Kudryashov, Alexis V.; Kawanaka, Junji; Miyanaga, Noriaki

2016-07-01

We have fabricated a 410 x 468 mm size deformable mirror with 100 Bimorph piezoceramic actuators for the LFEX laser system at Osaka University. In the case of Bimorph-type deformable mirrors, the mirror surface had to be polished and coated after bonding the piezoceramic actuators to the rear side of the thin mirror substrate. This provides a good surface figure, but the coating temperature for the high-reflection mirror was strictly limited because of the thermal fragility of piezoceramic actuators. The mirror substrate with the actuators was polished, and an ion-assisted multilayer dielectric coating was produced at 60 degrees Celsius with our 80-inch coating chamber. The flatness of the mirror just after coating was 7 μm, and reduced by aging to 3.2 μm when the mirror was assembled. The surface figure of the assembled mirror with 20 piezostack bonded actuators is demonstrated and a laser-induced damage threshold tested with a witness sample is also reported.

Gemini 8.2-m primary mirror no. 1 polishing

NASA Astrophysics Data System (ADS)

Cayrel, Marc; Beraud, P.; Paseri, Jacques; Dromas, E.

1998-08-01

The 8-m class primary mirrors of the GEMINI Telescopes are thin ULE menisci actively supported. The two mirror blanks are produced by CORNING, the optical figuring, manufacturing and assembling of interfaces are done by REOSC. REOSC is as well in charge of the transportation of the mirror blanks from CORNING to REOSC, and of the shipment of the finished optics to Hawaii and to Chile. The mirror assembly requirements are summarized, the manufacturing and testing methods are addressed. REOSC had to design and manufacture a dedicated active supporting system, representative of the one used at the telescope level. Its design and performance are presented. The manufacturing steps undertaken at REOSC and the results achieved are then detailed: mirror blank surface generating and grinding, polishing, testing. The current status of the mirrors is finally presented.

Performance of lightweight large C/SiC mirror

NASA Astrophysics Data System (ADS)

Yui, Yukari Y.; Goto, Ken; Kaneda, Hidehiro; Katayama, Haruyoshi; Kotani, Masaki; Miyamoto, Masashi; Naitoh, Masataka; Nakagawa, Takao; Saruwatari, Hideki; Suganuma, Masahiro; Sugita, Hiroyuki; Tange, Yoshio; Utsunomiya, Shin; Yamamoto, Yasuji; Yamawaki, Toshihiko

2017-11-01

Very lightweight mirror will be required in the near future for both astronomical and earth science/observation missions. Silicon carbide is becoming one of the major materials applied especially to large and/or light space-borne optics, such as Herschel, GAIA, and SPICA. On the other hand, the technology of highly accurate optical measurement of large telescopes, especially in visible wavelength or cryogenic circumstances is also indispensable to realize such space-borne telescopes and hence the successful missions. We have manufactured a very lightweight Φ=800mm mirror made of carbon reinforced silicon carbide composite that can be used to evaluate the homogeneity of the mirror substrate and to master and establish the ground testing method and techniques by assembling it as the primary mirror into an optical system. All other parts of the optics model are also made of the same material as the primary mirror. The composite material was assumed to be homogeneous from the mechanical tests of samples cut out from the various areas of the 800mm mirror green-body and the cryogenic optical measurement of the mirror surface deformation of a 160mm sample mirror that is also made from the same green-body as the 800mm mirror. The circumstance and condition of the optical testing facility has been confirmed to be capable for the highly precise optical measurements of large optical systems of horizontal light axis configuration. Stitching measurement method and the algorithm for analysis of the measurement is also under study.

James Webb Space Telescope: Frequently Asked Questions for Scientists and Engineers

NASA Technical Reports Server (NTRS)

Gardner, Jonathan P.

2008-01-01

JWST will be tested incrementally during its construction, starting with individual mirrors and instruments (including cameras and spectrometers) and building up to the full observatory. JWST's mirrors and the telescope structure are first each tested individually, including optical testing of the mirrors and alignment testing of the structure inside a cold thermal-vacuum chamber. The mirrors are then installed on the telescope structure in a clean room at Goddard Space Flight Center (GSFC). In parallel to the telescope assembly and alignment, the instruments are being built and tested, again first individually, and then as part of an integrated instrument assembly. The integrated instrument assembly will be tested in a thermal-vacuum chamber at GSFC using an optical simulator of the telescope. This testing makes sure the instruments are properly aligned relative to each other and also provides an independent check of the individual tests. After both the telescope and the integrated instrument module are successfully assembled, the integrated instrument module will be installed onto the telescope, and the combined system will be sent to Johnson Space Flight Center (JSC) where it will be optically tested in one of the JSC chambers. The process includes testing the 18 primary mirror segments acting as a single primary mirror, and testing the end-to-end system. The final system test will assure that the combined telescope and instruments are focused and aligned properly, and that the alignment, once in space, will be within the range of the actively controlled optics. In general, the individual optical tests of instruments and mirrors are the most accurate. The final system tests provide a cost-effective check that no major problem has occurred during assembly. In addition, independent optical checks of earlier tests will be made as the full system is assembled, providing confidence that there are no major problems.

Novel high-bandwidth bimorph deformable mirrors

NASA Astrophysics Data System (ADS)

Griffith, Michael S.; Laycock, Leslie C.; Archer, Nick J.

2004-12-01

Adaptive Optics (AO) is a critical underpinning technology for future laser delivery (including free-space optical communications), target illumination and imaging systems. It measures and compensates for optical distortion caused by transmission through the atmosphere, resulting in the ability to deploy smaller lasers and identify targets at greater ranges. One of the key components in an AO system is the wavefront modifier, which acts on the incoming or outgoing beam to counter the effects of the atmosphere. BAE SYSTEMS Advanced Technology Centre is developing multi-element bimorph deformable mirrors for such an applications. Our initial designs were based on a standard construction and exhibited a resonant frequency of 1kHz with a maximum stroke of +/-20μm for an active aperture of 50mm. These devices were limited by the necessity to have a 'dead space' between the inner active area and the mirror boundary; this ensured that both the requirements for the stroke and the fixed boundary conditions could be met simultaneously. However, there was a significant penalty to pay in terms of bandwidth, which is inversely proportional to the square of the full mirror diameter. In a series of iteration steps, we have created novel mounting arrangements that reduce dead space and thus provide the optimum trade-off between bandwidth and stroke. These schemes include supporting the mirror from underneath, rather than at its edge. As a result, models of 60mm active diameter mirrors predict a resonance in excess of 5kHz, combined with a maximum stroke greater than +/-40μm. This paper will discuss a number of different mirror designs and present experimental results for recently assembled devices.

Projection optics box

DOEpatents

Hale, Layton C.; Malsbury, Terry; Hudyma, Russell M.; Parker, John M.

2000-01-01

A projection optics box or assembly for use in an optical assembly, such as in an extreme ultraviolet lithography (EUVL) system using 10-14 nm soft x-ray photons. The projection optics box utilizes a plurality of highly reflective optics or mirrors, each mounted on a precision actuator, and which reflects an optical image, such as from a mask, in the EUVL system onto a point of use, such as a target or silicon wafer, the mask, for example, receiving an optical signal from a source assembly, such as a developed from laser system, via a series of highly reflective mirrors of the EUVL system. The plurality of highly reflective optics or mirrors are mounted in a housing assembly comprised of a series of bulkheads having wall members secured together to form a unit construction of maximum rigidity. Due to the precision actuators, the mirrors must be positioned precisely and remotely in tip, tilt, and piston (three degrees of freedom), while also providing exact constraint.

Driving and latching of the Starlab pointing mirror doors

NASA Technical Reports Server (NTRS)

Beaven, Herbert R., Jr.; Avina, Raymond R.

1990-01-01

The Starlab Experiment, a major SDIO technology initiative, is an attached payload which will be delivered into Earth orbit aboard NASA's Space Shuttle in 1991. Starlab will generate and aim an 80 cm diameter laser beam into space through a large opening in the structure which houses the pointing mirror. Two doors, each somewhat larger than a desktop, cover the opening when the laser optics system is nonoperational. Latch Mechanism Assemblies hold the doors shut during liftoff and ascent and, again, during Orbiter reentry. Each door is powered by a Door Drive System during the many open/close cycles between various experiments. The design, testing, and resultant failure modes of these mechanisms are examined.

Glass sample characterization

NASA Technical Reports Server (NTRS)

Ahmad, Anees

1990-01-01

The development of in-house integrated optical performance modelling capability at MSFC is described. This performance model will take into account the effects of structural and thermal distortions, as well as metrology errors in optical surfaces to predict the performance of large an complex optical systems, such as Advanced X-Ray Astrophysics Facility. The necessary hardware and software were identified to implement an integrated optical performance model. A number of design, development, and testing tasks were supported to identify the debonded mirror pad, and rebuilding of the Technology Mirror Assembly. Over 300 samples of Zerodur were prepared in different sizes and shapes for acid etching, coating, and polishing experiments to characterize the subsurface damage and stresses produced by the grinding and polishing operations.

The GTC: a convenient test bench for ELT demonstrations

NASA Astrophysics Data System (ADS)

Rodriguez Espinosa, Jose M.; Hammersley, Peter L.; Martinez-Roger, Carlos

2004-07-01

The Gran Telescopio Canarias (GTC) is, being assembled at the Observatorio del Roque de los Muchachos (ORM) in the island of La Palma. First light is expected for early 2005 with the first science observations late in 2005. The GTC, being a segmented primary mirror telescope, could be employed for testing several technological aspects relevant to the future generation of Extremely Large Telescopes (ELT). In the short term, the mass production of aespheric mirror segments can be examined in detail and improvements made along the way, or planned for the future. Indeed the GTC segments are now entering into a chain production scheme. Later on, different strategies for the control aspects of the primary mirror can be explored to optimize the optical performance of segmented telescopes. Moreover, the entire GTC active optics can offer a learning tool for testing various strategies and their application to ELTs.

The UltraLightweight Technology for Research in Astronomy (ULTRA) Project

NASA Astrophysics Data System (ADS)

Twarog, B. A.; Anthony-Twarog, B. J.; Shawl, S. J.; Hale, R.; Taghavi, R.; Fesen, R.; Etzel, P. B.; Martin, R.; Romeo, R.

2004-12-01

The collaborative focus of four academic departments (Univ. of Kansas Aerospace Engineering, Univ. of Kansas Physics & Astronomy, San Diego State University Astronomy and Dartmouth College Astronomy) and a private industry partner (Composite Mirror Applications, Inc.-CMA, Inc.) is a three-year plan to develop and test UltraLightweight Technology for Research in Astronomy (ULTRA). The ULTRA technology, using graphite fiber composites to fabricate mirrors and telescope structures, offers a versatile and cost-effective tool for optical astronomy, including the economical fabrication and operation of telescopes ranging from small (1m or smaller) aperture for education and research to extremely large (30m+) segmented telescopes (ELTs). The specific goal of this NSF-funded three-year Major Research Instrumentation project is to design, build, and test a 1m-class optical tube assembly (OTA) and mirrors constructed entirely from composites. In the first year of the project, the team has built and is field-testing two 0.4m prototypes to validate the optical surfaces and figures of the mirrors and to test and refine the structural dynamics of the OTA. Preparation for design and construction of the 1m telescope is underway. When completed in late 2005, the ULTRA telescope will be operated remotely from Mt. Laguna Observatory east of San Diego, where it will undergo a period of intensive optical and imaging tests. A 0.4m prototype OTA with mirrors (12 kg total weight) will be on display at the meeting. Support of this work by NSF through grants AST-0320784 and AST-0321247, NASA grant NCC5-600, the University of Kansas, and San Diego State University is gratefully acknowledged.

Castable Amorphous Metal Mirrors and Mirror Assemblies

NASA Technical Reports Server (NTRS)

Hofmann, Douglas C.; Davis, Gregory L.; Agnes, Gregory S.; Shapiro, Andrew A.

2013-01-01

A revolutionary way to produce a mirror and mirror assembly is to cast the entire part at once from a metal alloy that combines all of the desired features into the final part: optical smoothness, curvature, flexures, tabs, isogrids, low CTE, and toughness. In this work, it has been demonstrated that castable mirrors are possible using bulk metallic glasses (BMGs, also called amorphous metals) and BMG matrix composites (BMGMCs). These novel alloys have all of the desired mechanical and thermal properties to fabricate an entire mirror assembly without machining, bonding, brazing, welding, or epoxy. BMGs are multi-component metal alloys that have been cooled in such a manner as to avoid crystallization leading to an amorphous (non-crystalline) microstructure. This lack of crystal structure and the fact that these alloys are glasses, leads to a wide assortment of mechanical and thermal properties that are unlike those observed in crystalline metals. Among these are high yield strength, carbide-like hardness, low melting temperatures (making them castable like aluminum), a thermoplastic processing region (for improving smoothness), low stiffness, high strength-to-weight ratios, relatively low CTE, density similar to titanium alloys, high elasticity and ultra-smooth cast parts (as low as 0.2-nm surface roughness has been demonstrated in cast BMGs). BMGMCs are composite alloys that consist of a BMG matrix with crystalline dendrites embedded throughout. BMGMCs are used to overcome the typically brittle failure observed in monolithic BMGs by adding a soft phase that arrests the formation of cracks in the BMG matrix. In some cases, BMGMCs offer superior castability, toughness, and fatigue resistance, if not as good a surface finish as BMGs. This work has demonstrated that BMGs and BMGMCs can be cast into prototype mirrors and mirror assemblies without difficulty.

A 4-m evolvable space telescope configured for NASA's HabEx Mission: the initial stage of LUVOIR

NASA Astrophysics Data System (ADS)

Lillie, Charles F.; MacEwen, Howard A.; Polidan, Ronald S.; Breckinridge, James B.

2017-09-01

Previous papers have described our concept for a large telescope that would be assembled in space in several stages (in different configurations) over a period of fifteen to 20 years. Spreading the telescope development, launch and operations cost over 20 years would minimize the impact on NASA's annual budget and drastically shorten the time between program start and "first light" for this space observatory. The first Stage of this Evolvable Space Telescope (EST) would consist of an instrument module located at the prime focus of three 4-meter hexagonal mirrors arranged in a semi-circle to form one-half of a 12-m segmented mirror. After several years three additional 4-m mirrors would be added to create a 12-m filled aperture. Later, twelve more 4-m mirrors will be added to this Stage 2 telescope to create a 20-m filled aperture space telescope. At each stage the telescope would have an unparalleled capability for UVOIR observations, and the results of these observations will guide the evolution of the telescope and its instruments. In this paper we describe our design concept for an initial configuration of our Evolvable Space Telescope that can meet the requirements of the 4-m version of the HabEx spacecraft currently under consideration by NASA's Habitable Exoplanet Science and Technology Definition Team. This "Stage Zero" configuration will have only one 4-m mirror segment with the same 30-m focal length and a prime focus coronagraph with normal incidence optics to minimize polarization effects. After assembly and checkout in cis-lunar space, the telescope would transfer to a Sun-Earth L2 halo orbit and obtain high sensitivity, high resolution, high contrast UVOIR observations that address the scientific objectives of the Habitable-Exoplanet Imaging Missions.

Opto-Mechanics of the Constellation-X SXT Mirrors: Challenges in Mounting and Assembling the Mirror Segments

NASA Technical Reports Server (NTRS)

Chan, Kai-Wing; Zhang, WIlliam W.; Saha, Timo; Lehan, John P.; Mazzarella, James; Lozipone, Lawrence; Hong, Melinda; Byron, Glenn

2008-01-01

The Constellation-X Spectroscopy X-Ray Telescopes consists of segmented glass mirrors with an axial length of 200 mm, a width of up to 400 mm, and a thickness of 0.4 mm. To meet the requirement of less than 15 arc-second half-power diameter with the small thickness and relatively large size is a tremendous challenge in opto-mechanics. How shall we limit distortion of the mirrors due to gravity in ground tests, that arises from thermal stress, and that occurs in the process of mounting, affixing and assembling of these mirrors? In this paper, we will describe our current opto-mechanical approach to these problems. We will discuss, in particular, the approach and experiment where the mirrors are mounted vertically by first suspending it at two points.

Mirror image DNA nanostructures for chiral supramolecular assemblies.

PubMed

Lin, Chenxiang; Ke, Yonggang; Li, Zhe; Wang, James H; Liu, Yan; Yan, Hao

2009-01-01

L-DNA, the mirror image of natural D-DNA, can be readily self-assembled into designer discrete or periodic nanostructures. The assembly products are characterized by polyacrylamide gel electrophoresis, circular dichroism spectrum, atomic force microscope, and fluorescence microscope. We found that the use of enantiomer DNA as building material leads to the formation of DNA supramolecules with opposite chirality. Therefore, the L-DNA self-assembly is a substantial complement to the structural DNA nanotechnology. Moreover, the L-DNA architectures feature superior nuclease resistance thus are appealing for in vivo medical applications.

Large Space Optics: From Hubble to JWST and Beyond

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2008-01-01

If necessity truly is the mother of invention, then advances in lightweight space mirror technology have been driven by launch vehicle mass and volume constraints. In the late 1970 s, at the start of Hubble development, the state of the art in ground based telescopes was 3 to 4 meter monolithic primary mirrors with masses of 6000 to 10,000 kg - clearly too massive for the planned space shuttle 25,000 kg capability to LEO. Necessity led Hubble to a different solution. Launch vehicle mass constraints (and cost) resulted in the development of a 2.4 meter lightweight eggcrate mirror. At 810 kg (180 kg/m2), this mirror was approximately 7.4% of HST s total 11,110 kg mass. And, the total observatory structure at 4.3 m x 13.2 m fit snuggly inside the space shuttle 4.6 m x 18.3 m payload bay. In the early 1990 s, at the start of JWST development, the state of the art in ground based telescopes was 8 meter class monolithic primary mirrors (16,000 to 23,000 kg) and 10 meter segmented mirrors (14,400 kg). Unfortunately, launch vehicles were still constrained to 4.5 meter payloads and 25,000 kg to LEO or 6,600 kg to L2. Furthermore, science now demanded a space telescope with 6 to 8 meter aperture operating at L2. Mirror technology was identified as a critical capability necessary to enable the next generation of large aperture space telescopes. Specific telescope architectures were explored via three independent design concept studies conducted during the summer of 1996 (1). These studies identified two significant architectural constraints: segmentation and areal density. Because the launch vehicle fairing payload dynamic envelop diameter is approximately 4.5 meters, the only way to launch an 8 meter class mirror is to segment it, fold it and deploy it on orbit - resulting in actuation and control requirements. And, because of launch vehicle mass limits, the primary mirror allocation was only 1000 kg - resulting in a maximum areal density of 20 kg/m2. At the inception of JWST in 1996, such a capability did not exist. A highly successful technology development program was initiated resulting in matured and demonstrated mirror technology for JWST (2, 3). Today, the JWST 6.5 meter primary mirror has an areal density of 25 kg/m2 for a total mass of 625 kg or 9.6% of the total JWST observatory mass of 6,500 kg. Looking into the future, science requires increasing larger collecting apertures. Ground based telescopes are already moving towards 30+ meter mirrors. The only way to meet this challenge for space telescopes is via even lower areal density mirrors or on-orbit assembly or larger launch vehicles (4). The planned NASA Ares V with its 10 meter fairing and 55,000 kg payload to L2 eliminates this constraint (5).

Extraction and analysis of the image in the sight field of comparison goniometer to measure IR mirrors assembly

NASA Astrophysics Data System (ADS)

Wang, Zhi-shan; Zhao, Yue-jin; Li, Zhuo; Dong, Liquan; Chu, Xuhong; Li, Ping

2010-11-01

The comparison goniometer is widely used to measure and inspect small angle, angle difference, and parallelism of two surfaces. However, the common manner to read a comparison goniometer is to inspect the ocular of the goniometer by one eye of the operator. To read an old goniometer that just equips with one adjustable ocular is a difficult work. In the fabrication of an IR reflecting mirrors assembly, a common comparison goniometer is used to measure the angle errors between two neighbor assembled mirrors. In this paper, a quick reading technique image-based for the comparison goniometer used to inspect the parallelism of mirrors in a mirrors assembly is proposed. One digital camera, one comparison goniometer and one set of computer are used to construct a reading system, the image of the sight field in the comparison goniometer will be extracted and recognized to get the angle positions of the reflection surfaces to be measured. In order to obtain the interval distance between the scale lines, a particular technique, left peak first method, based on the local peak values of intensity in the true color image is proposed. A program written in VC++6.0 has been developed to perform the color digital image processing.

PHyTIR - A Prototype Thermal Infrared Radiometer

NASA Technical Reports Server (NTRS)

Jau, Bruno M.; Hook, Simon J.; Johnson, William R.; Foote, Marc C.; Paine, Christopher G.; Pannell, Zack W.; Smythe, Robert F.; Kuan, Gary M.; Jakoboski, Julie K.; Eng, Bjorn T.

2013-01-01

This paper describes the PHyTIR (Prototype HyspIRI Thermal Infrared Radiometer) instrument, which is the engineering model for the proposed HyspIRI (Hyperspectral Infrared Imager) earth observing instrument. The HyspIRI mission would be comprised of the HyspIRI TIR (Thermal Infrared Imager), and a VSWIR (Visible Short-Wave Infra-Red Imaging Spectrometer). Both instruments would be used to address key science questions related to the earth's carbon cycle, ecosystems, climate, and solid earth properties. Data gathering of volcanic activities, earthquakes, wildfires, water use and availability, urbanization, and land surface compositions and changes, would aid the predictions and evaluations of such events and the impact they create. Even though the proposed technology for the HyspIRI imager is mature, the PHyTIR prototype is needed to advance the technology levels for several of the instrument's key components, and to reduce risks, in particular to validate 1) the higher sensitivity, spatial resolution, and higher throughput required for this focal plane array, 2) the pointing accuracy, 2) the characteristics of several spectral channels, and 4) the use of ambient temperature optics. The PHyTIR telescope consists of the focal plane assembly that is housed within a cold housing located inside a vacuum enclosure; all mounted to a bulkhead, and an optical train that consists of 3 powered mirrors; extending to both sides of the bulkhead. A yoke connects the telescope to a scan mirror. The rotating mirror enables to scan- a large track on the ground. This structure is supported by kinematic mounts, linking the telescope assembly to a base plate that would also become the spacecraft interface for HyspIRI. The focal plane's cooling units are also mounted to the base plate, as is an overall enclosure that has two viewing ports with large exterior baffles, shielding the focal plane from incoming stray light. PHyTIR's electronics is distributed inside and near the vacuum enclosure, and in a nearby rack. The data acquisition technique would be to take measurements over a 51deg wide swath in the cross spacecraft velocity direction, which is brought into view through the rotating scan mirror. A landscape mosaic thus can be assembled by overlaying rows of measurements. The paper briefly outlines the proposed HyspIRI mission and its data acquisition technique; it then describes the prototype PHyTIR instrument.

Process of constructing a lightweight x-ray flight mirror assembly

NASA Astrophysics Data System (ADS)

McClelland, Ryan S.; Biskach, Michael P.; Chan, Kai-Wing; Espina, Rebecca A.; Hohl, Bruce R.; Saha, Timo T.; Zhang, William W.

2014-07-01

Lightweight and high resolution optics are needed for future space-based x-ray telescopes to achieve advances in highenergy astrophysics. NASA's Next Generation X-ray Optics (NGXO) project has made significant progress towards building such optics, both in terms of maturing the technology for spaceflight readiness and improving the angular resolution. Technology Development Modules (TDMs) holding three pairs of mirrors have been regularly and repeatedly integrated and tested both for optical performance and mechanical strength. X-ray test results have been improved over the past year from 10.3 arc-seconds Half Power Diameter (HPD) to 8.3 arc-seconds HPD. A vibration test has been completed to NASA standard verification levels showing the optics can survive launch and pointing towards improvements in strengthening the modules through redundant bonds. A Finite Element Analysis (FEA) study was completed which shows the mirror distortion caused by bonding is insensitive to the number of bonds. Next generation TDMs, which will demonstrate a lightweight structure and mount additional pairs of mirrors, have been designed and fabricated. The light weight of the module structure is achieved through the use of E-60 Beryllium Oxide metal matrix composite material. As the angular resolution of the development modules has improved, gravity distortion during horizontal x-ray testing has become a limiting factor. To address this issue, a facility capable of testing in the vertical orientation has been designed and planned. Test boring at the construction site suggest standard caisson construction methods can be utilized to install a subterranean vertical vacuum pipe. This facility will also allow for the testing of kinematically mounted mirror segments, which greatly reduces the effect of bonding displacements. A development platform demonstrating the feasibility of kinematically mounting mirror segments has been designed, fabricated, and successfully tested.

Characterization of the JWST Pathfinder mirror dynamics using the center of curvature optical assembly (CoCOA)

NASA Astrophysics Data System (ADS)

Wells, Conrad; Hadaway, James B.; Olczak, Gene; Cosentino, Joseph; Johnston, John D.; Whitman, Tony; Connolly, Mark; Chaney, David; Knight, J. Scott; Telfer, Randal

2016-07-01

The James Webb Space Telescope (JWST) Optical Telescope Element (OTE) consists of a 6.6 m clear aperture, 18 segment primary mirror, all-reflective, three-mirror anastigmat operating at cryogenic temperatures. To verify performance of the primary mirror, a full aperture center of curvature optical null test is performed under cryogenic conditions in Chamber A at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) using an instantaneous phase measuring interferometer. After phasing the mirrors during the JWST Pathfinder testing, the interferometer is utilized to characterize the mirror relative piston and tilt dynamics under different facility configurations. The correlation between the motions seen on detectors at the focal plane and the interferometer validates the use of the interferometer for dynamic investigations. The success of planned test hardware improvements will be characterized by the multi-wavelength interferometer (MWIF) at the Center of Curvature Optical Assembly (CoCOA).

Characterization of the JWST Pathfinder Mirror Dynamics Using the Center of Curvature Optical Assembly (CoCOA)

NASA Technical Reports Server (NTRS)

Wells, Conrad; Hadaway, James B.; Olczak, Gene; Cosentino, Joseph; Johnston, John D.; Whitman, Tony; Connolly, Mark; Chaney, David; Knight, J. Scott; Telfer, Randal

2016-01-01

The JWST (James Webb Space Telescope) Optical Telescope Element (OTE) consists of a 6.6 meter clear aperture, 18-segment primary mirror, all-reflective, three-mirror anastigmat operating at cryogenic temperatures. To verify performance of the primary mirror, a full aperture center of curvature optical null test is performed under cryogenic conditions in Chamber A at NASA Johnson Space Center using an instantaneous phase measuring interferometer. After phasing the mirrors during the JWST Pathfinder testing, the interferometer is utilized to characterize the mirror relative piston and tilt dynamics under different facility configurations. The correlation between the motions seen on detectors at the focal plane and the interferometer validates the use of the interferometer for dynamic investigations. The success of planned test hardware improvements will be characterized by the multi-wavelength interferometer (MWIF) at the Center of Curvature Optical Assembly (CoCOA).

Lightweight and High-Resolution Single Crystal Silicon Optics for X-ray Astronomy

NASA Technical Reports Server (NTRS)

Zhang, William W.; Biskach, Michael P.; Chan, Kai-Wing; Mazzarella, James R.; McClelland, Ryan S.; Riveros, Raul E.; Saha, Timo T.; Solly, Peter M.

2016-01-01

We describe an approach to building mirror assemblies for next generation X-ray telescopes. It incorporates knowledge and lessons learned from building existing telescopes, including Chandra, XMM-Newton, Suzaku, and NuSTAR, as well as from our direct experience of the last 15 years developing mirror technology for the Constellation-X and International X-ray Observatory mission concepts. This approach combines single crystal silicon and precision polishing, thus has the potential of achieving the highest possible angular resolution with the least possible mass. Moreover, it is simple, consisting of several technical elements that can be developed independently in parallel. Lastly, it is highly amenable to mass production, therefore enabling the making of telescopes of very large photon collecting areas.

Dynamic Loading Assembly for Testing Actuators of Segmented Mirror Telescope

NASA Astrophysics Data System (ADS)

Deshmukh, Prasanna Gajanan; Parihar, Padmakar; Balasubramaniam, Karthik A.; Mishra, Deepta Sundar; Mahesh, P. K.

Upcoming large telescopes are based on Segmented Mirror Telescope (SMT) technology which uses small hexagonal mirror segments placed side by side to form the large monolithic surface. The segments alignment needs to be maintained against external disturbances like wind, gravity, temperature and structural vibration. This is achieved by using three position actuators per segment working at few-nanometer scale range along with a local closed loop controller. The actuator along with a controller is required to meet very stringent performance requirements, such as track rates up to 300nm/s (90mN/s) with tracking errors less than 5nm, dynamical forces of up to ±40N, ability to reject disturbances introduced by the wind as well as by mechanical vibration generated in the mirror cell, etc. To conduct these performance tests in more realistic manner, we have designed and developed a Dynamic Loading Assembly (DLA) at Indian Institute of Astrophysics (IIA), Bangalore. DLA is a computer controlled force-inducing device, designed in a modular fashion to generate different types of user-defined disturbances in extremely precise and controlled manner. Before realizing the device, using a simple spring-mass-damper-based mathematical model, we ensured that the concept would indeed work. Subsequently, simple concept was converted into a detailed mechanical design and parts were manufactured and assembled. DLA has static and dynamic loading capabilities up to 250N and 18N respectively, with a bandwidth sufficient to generate wind disturbances. In this paper, we present various performance requirements of SMT actuators as well as our effort to develop a dynamic loading device which can be used to test these actuators. Well before using DLA for meaningful testing of the actuator, the DLA itself have gone through various tests and improvements phases. We have successfully demonstrated that DLA can be used to check the extreme performance of two different SMT actuators, which are expected to track the position/force with a few nanometer accuracy.

Self-assembled mirror DNA nanostructures for tumor-specific delivery of anticancer drugs.

PubMed

Kim, Kyoung-Ran; Kim, Hyo Young; Lee, Yong-Deok; Ha, Jong Seong; Kang, Ji Hee; Jeong, Hansaem; Bang, Duhee; Ko, Young Tag; Kim, Sehoon; Lee, Hyukjin; Ahn, Dae-Ro

2016-12-10

Nanoparticle delivery systems have been extensively investigated for targeted delivery of anticancer drugs over the past decades. However, it is still a great challenge to overcome the drawbacks of conventional nanoparticle systems such as liposomes and micelles. Various novel nanomaterials consist of natural polymers are proposed to enhance the therapeutic efficacy of anticancer drugs. Among them, deoxyribonucleic acid (DNA) has received much attention as an emerging material for preparation of self-assembled nanostructures with precise control of size and shape for tailored uses. In this study, self-assembled mirror DNA tetrahedron nanostructures is developed for tumor-specific delivery of anticancer drugs. l-DNA, a mirror form of natural d-DNA, is utilized for resolving a poor serum stability of natural d-DNA. The mirror DNA nanostructures show identical thermodynamic properties to that of natural d-DNA, while possessing far enhanced serum stability. This unique characteristic results in a significant effect on the pharmacokinetics and biodistribution of DNA nanostructures. It is demonstrated that the mirror DNA nanostructures can deliver anticancer drugs selectively to tumors with enhanced cellular and tissue penetration. Furthermore, the mirror DNA nanostructures show greater anticancer effects as compared to that of conventional PEGylated liposomes. Our new approach provides an alternative strategy for tumor-specific delivery of anticancer drugs and highlights the promising potential of the mirror DNA nanostructures as a novel drug delivery platform. Copyright © 2016 Elsevier B.V. All rights reserved.

Around Marshall

NASA Image and Video Library

2003-04-09

This photo (a frontal view) is of one of many segments of the Eastman-Kodak mirror assembly being tested for the James Webb Space Telescope (JWST) project at the X-Ray Calibration Facility at Marshall Space Flight Center (MSFC). MSFC is supporting Goddard Space Flight Center (GSFC) in developing the JWST by taking numerous measurements to predict its future performance. The tests are conducted in a vacuum chamber cooled to approximate the super cold temperatures found in space. During its 27 years of operation, the facility has performed testing in support of a wide array of projects, including the Hubble Space Telescope (HST), Solar A, Chandra technology development, Chandra High Resolution Mirror Assembly and science instruments, Constellation X-Ray Mission, and Solar X-Ray Imager, currently operating on a Geostationary Operational Environment Satellite. The JWST is NASA's next generation space telescope, a successor to the Hubble Space Telescope, named in honor of NASA's second administrator, James E. Webb. It is scheduled for launch in 2010 aboard an expendable launch vehicle. It will take about 3 months for the spacecraft to reach its destination, an orbit of 940,000 miles in space.

Systems level feasibility study for the detection of extra-solar planets. Volume 1: Infrared interferometer (IRIS) known as the Stanford Concept

NASA Technical Reports Server (NTRS)

1979-01-01

A sensor system for the direct detection of extrasolar planets from an Earth orbit is evaluated: a spinning, infrared interferometer (IRIS). It is shuttle deployed, free flying, requires no on-orbit assembly and no reservicing over a design life of five years. The sensor concept and the mission objectives are reviewed, and the performance characteristics of a baseline sensor for standard observation conditions are derived. A baseline sensor design is given and the enabling technology discussed. Cost and weight estimates are performed; and a schedule for an IRIS program including technology development and assessment of risk are given. Finally, the sensor is compared with the apodized visual telescope sensor (APOTS) proposed for the same mission. The major conclusions are: that with moderate to strong technology advances, particularly in the fields of long life cryogenics, dynamical control, mirror manufacturing, and optical alignment, the detection of a Jupiter like planet around a Sunlike star at a distance of 30 light years is feasible, with a 3 meter aperture and an observation time of 1 hour. By contrast, major and possibly unlikely breakthroughs in mirror technology are required for APOTS to match this performance.

Design of the GOES Telescope secondary mirror mounting

NASA Technical Reports Server (NTRS)

Hookman, Robert A.

1989-01-01

The GOES Telescope utilizes a flexure mounting system for the secondary mirror to minimize thermally induced distortions of the secondary mirror. The detailed design is presented along with a discussion of the microradian pointing requirements and how they were achieved. The methodology used to dynamically tune the flexure/secondary mirror assembly to minimize structural interactions will also be discussed.

Adjusting Curvatures Of Large Mirrors And Lenses

NASA Technical Reports Server (NTRS)

Birnbaum, Morris M.

1992-01-01

Actuators apply stresses to generate distortions counteracting undesired distortions in technique for adjusting curvature of large focusing mirror or lens. Motor-and-gear assemblies under remote control vary squeeze of ring clamp and push or pull of hollow shaft to make fine adjustments in curvature of mirror. Applicable to large astronomical-telescope mirrors with diameters of 60 cm or more.

Performance Reports: Mirror alignment system performance prediction comparison between SAO and EKC

NASA Technical Reports Server (NTRS)

Tananbaum, H. D.; Zhang, J. P.

1994-01-01

The objective of this study is to perform an independent analysis of the residual high resolution mirror assembly (HRMA) mirror distortions caused by force and moment errors in the mirror alignment system (MAS) to statistically predict the HRMA performance. These performance predictions are then compared with those performed by Kodak to verify their analysis results.

Using the ISS as a Testbed to Prepare for the Next Generation of Space-Based Telescopes

NASA Technical Reports Server (NTRS)

Ess, Kim; Thronson, Harley; Boyles, Mark; Sparks, William; Postman, Marc; Carpenter, Kenneth

2012-01-01

The ISS provides a unique opportunity to develop the technologies and operational capabilities necessary to assemble future large space telescopes that may be used to investigate planetary systems around neighboring stars. Assembling telescopes in space is a paradigm-shifting approach to space astronomy. Using the ISS as a testbed will reduce the technical risks of implementing this major scientific facility, such as laser metrology and wavefront sensing and control (WFSC). The Optical Testbed and Integration on ISS eXperiment (OpTIIX) will demonstrate the robotic assembly of major components, including the primary and secondary mirrors, to mechanical tolerances using existing ISS infrastructure, and the alignment of the optical elements to a diffraction-limited optical system in space. Assembling the optical system and removing and replacing components via existing ISS capabilities, such as the Special Purpose Dexterous Manipulator (SPDM) or the ISS flight crew, allows for future experimentation and repair, if necessary. First flight on ISS for OpTIIX, a small 1.5 meter optical telescope, is planned for 2015. In addition to demonstration of key risk-retiring technologies, the OpTIIX program includes a public outreach program to show the broad value of ISS utilization.

Solar power from satellites

NASA Technical Reports Server (NTRS)

Glaser, P. E.

1977-01-01

Microwave beaming of satellite-collected solar energy to earth for conversion to useful industrial power is evaluated for feasibility, with attention given to system efficiencies and costs, ecological impact, hardware to be employed, available options for energy conversion and transmission, and orbiting and assembly. Advantages of such a power generation and conversion system are listed, plausible techniques for conversion of solar energy (thermionic, thermal electric, photovoltaic) and transmission to earth (lasers, arrays of mirrors, microwave beams) are compared. Structural fatigue likely to result from brief daily eclipses, 55% system efficiency at the present state of the art, present projections of system costs, and projected economic implications of the technology are assessed. Two-stage orbiting and assembly plans are described.

Design and Analysis of an X-Ray Mirror Assembly Using the Meta-Shell Approach

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; Bonafede, Joseph; Saha, Timo T.; Solly, Peter M.; Zhang, William W.

2016-01-01

Lightweight and high resolution optics are needed for future space-based x-ray telescopes to achieve advances in high-energy astrophysics. Past missions such as Chandra and XMM-Newton have achieved excellent angular resolution using a full shell mirror approach. Other missions such as Suzaku and NuSTAR have achieved lightweight mirrors using a segmented approach. This paper describes a new approach, called meta-shells, which combines the fabrication advantages of segmented optics with the alignment advantages of full shell optics. Meta-shells are built by layering overlapping mirror segments onto a central structural shell. The resulting optic has the stiffness and rotational symmetry of a full shell, but with an order of magnitude greater collecting area. Several meta-shells so constructed can be integrated into a large x-ray mirror assembly by proven methods used for Chandra and XMM-Newton. The mirror segments are mounted to the meta-shell using a novel four point semi-kinematic mount. The four point mount deterministically locates the segment in its most performance sensitive degrees of freedom. Extensive analysis has been performed to demonstrate the feasibility of the four point mount and meta-shell approach. A mathematical model of a meta-shell constructed with mirror segments bonded at four points and subject to launch loads has been developed to determine the optimal design parameters, namely bond size, mirror segment span, and number of layers per meta-shell. The parameters of an example 1.3 m diameter mirror assembly are given including the predicted effective area. To verify the mathematical model and support opto-mechanical analysis, a detailed finite element model of a meta-shell was created. Finite element analysis predicts low gravity distortion and low sensitivity to thermal gradients.

Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

NASA Technical Reports Server (NTRS)

Page, Arthur T.

2001-01-01

This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(TM), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(TM) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(TM) generates the SINDA input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment, conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

Thermal Analysis of a Finite Element Model in a Radiation Dominated Environment

NASA Technical Reports Server (NTRS)

Page, Arhur T.

1999-01-01

This paper presents a brief overview of thermal analysis, evaluating the University of Arizona mirror design, for the Next Generation Space Telescope (NGST) Pre-Phase A vehicle concept. Model building begins using Thermal Desktop(Tm), by Cullimore and Ring Technologies, to import a NASTRAN bulk data file from the structural model of the mirror assembly. Using AutoCAD(R) capabilities, additional surfaces are added to simulate the thermal aspects of the problem which, for due reason, are not part of the structural model. Surfaces are then available to accept thermophysical and thermo-optical properties. Thermal Desktop(Tm) calculates radiation conductors using Monte Carlo simulations. Then Thermal Desktop(Tm) generates the SINDA/Fluint input file having a one-to-one correspondence with the NASTRAN node and element definitions. A model is now available to evaluate the mirror design in the radiation dominated environment conduct parametric trade studies of the thermal design, and provide temperatures to the finite element structural model.

Assembly and alignment method for optimized spatial resolution of off-axis three-mirror fore optics of hyperspectral imager.

PubMed

Kim, Youngsoo; Hong, Jinsuk; Choi, Byungin; Lee, Jong-Ung; Kim, Yeonsoo; Kim, Hyunsook

2017-08-21

A fore optics for the hyperspectral spectrometer is designed, manufactured, assembled, and aligned. The optics has a telecentric off-axis three-mirror configuration with a field of view wider than 14 degrees and an f-number as small as 2.3. The primary mirror (M1) and the secondary mirror (M2) are axially symmetric aspheric surfaces to minimize the sensitivity. The tertiary mirror (M3) is a decentered aspheric surface to minimize the coma and astigmatism aberration. The M2 also has a hole for the slit to maintain the optical performance while maximizing the telecentricity. To ensure the spatial resolution performance of the optical system, an alignment procedure is established to assemble and align the entrance slit of the spectrometer to the rear end of the fore optics. It has a great advantage to confirm and maintain the alignment integrity of the fore optics module throughout the alignment procedure. To perform the alignment procedure successfully, the precision movement control requirements are calculated and applied. As a result, the alignment goal of the RMS wave front error (WFE) to be smaller than 90 nm at all fields is achieved.

Thermal Model Development for an X-Ray Mirror Assembly

NASA Technical Reports Server (NTRS)

Bonafede, Joseph A.

2015-01-01

Space-based x-ray optics require stringent thermal environmental control to achieve the desired image quality. Future x-ray telescopes will employ hundreds of nearly cylindrical, thin mirror shells to maximize effective area, with each shell built from small azimuthal segment pairs for manufacturability. Thermal issues with these thin optics are inevitable because the mirrors must have a near unobstructed view of space while maintaining near uniform 20 C temperature to avoid thermal deformations. NASA Goddard has been investigating the thermal characteristics of a future x-ray telescope with an image requirement of 5 arc-seconds and only 1 arc-second focusing error allocated for thermal distortion. The telescope employs 135 effective mirror shells formed from 7320 individual mirror segments mounted in three rings of 18, 30, and 36 modules each. Thermal requirements demand a complex thermal control system and detailed thermal modeling to verify performance. This presentation introduces innovative modeling efforts used for the conceptual design of the mirror assembly and presents results demonstrating potential feasibility of the thermal requirements.

James Webb Space Telescope's Golden Mirror Unveiled

NASA Image and Video Library

2017-12-08

NASA engineers unveil the giant golden mirror of NASA's James Webb Space Telescope, and it's goldenly delicious! The 18 mirrors that make up the primary mirror were individually protected with a black covers when they were assembled on the telescope structure. Now, for the first time since the primary mirror was completed, the covers have been lifted. Standing tall and glimmering gold inside NASA's Goddard Space Flight Center's clean room in Greenbelt, Maryland, this mirror will be the largest yet sent into space. Currently, engineers are busy assembling and testing the other pieces of the telescope. Read more: go.nasa.gov/1TejHg4 Credit: NASA/Goddard/Chris Gunn NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Progress on SOFIA primary mirror

NASA Astrophysics Data System (ADS)

Geyl, Roland; Tarreau, Michel

2000-06-01

REOSC, SAGEM Group, has a significant contribution to the SOFIA project with the design and fabrication of the 2.7-m primary mirror and its fixtures as well as the M3 mirror tower assembly. This paper will primarily report the progress made on the primary mirror design and the first important manufacturing step: its lightweighting by machining pockets from the rear side of the blank.

Micro-assembly of three-dimensional rotary MEMS mirrors

NASA Astrophysics Data System (ADS)

Wang, Lidai; Mills, James K.; Cleghorn, William L.

2009-02-01

We present a novel approach to construct three-dimensional rotary micro-mirrors, which are fundamental components to build 1×N or N×M optical switching systems. A rotary micro-mirror consists of two microparts: a rotary micro-motor and a micro-mirror. Both of the two microparts are fabricated with PolyMUMPs, a surface micromachining process. A sequential robotic microassembly process is developed to join the two microparts together to construct a threedimensional device. In order to achieve high positioning accuracy and a strong mechanical connection, the micro-mirror is joined to the micro-motor using an adhesive mechanical fastener. The mechanical fastener has self-alignment ability and provides a temporary joint between the two microparts. The adhesive bonding can create a strong permanent connection, which does not require extra supporting plates for the micro-mirror. A hybrid manipulation strategy, which includes pick-and-place and pushing-based manipulations, is utilized to manipulation the micro-mirror. The pick-andplace manipulation has the ability to globally position the micro-mirror in six degrees of freedom. The pushing-based manipulation can achieve high positioning accuracy. This microassembly approach has great flexibility and high accuracy; furthermore, it does not require extra supporting plates, which greatly simplifies the assembly process.

NASA's James Webb Space Telescope Primary Mirror Fully Assembled

NASA Image and Video Library

2016-02-04

The 18th and final primary mirror segment is installed on what will be the biggest and most powerful space telescope ever launched. The final mirror installation Wednesday at NASA’s Goddard Space Flight Center in Greenbelt, Maryland marks an important milestone in the assembly of the agency’s James Webb Space Telescope. “Scientists and engineers have been working tirelessly to install these incredible, nearly perfect mirrors that will focus light from previously hidden realms of planetary atmospheres, star forming regions and the very beginnings of the Universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “With the mirrors finally complete, we are one step closer to the audacious observations that will unravel the mysteries of the Universe.” Using a robotic arm reminiscent of a claw machine, the team meticulously installed all of Webb's primary mirror segments onto the telescope structure. Each of the hexagonal-shaped mirror segments measures just over 4.2 feet (1.3 meters) across -- about the size of a coffee table -- and weighs approximately 88 pounds (40 kilograms). Once in space and fully deployed, the 18 primary mirror segments will work together as one large 21.3-foot diameter (6.5-meter) mirror. Credit: NASA/Goddard/Chris Gunn Credits: NASA/Chris Gunn

The Development and Optimisation of High Bandwidth Bimorph Deformable Mirrors

NASA Astrophysics Data System (ADS)

Rowe, D.; Laycock, L.; Griffith, M.; Archer, N.

Our first mirror designs were based on a standard bimorph construction and exhibited a resonant frequency of 1 kHz with a maximum stroke of ±5 μm. These devices were limited by the requirement to have a "dead space" between the inner active area and the mirror boundary. This was necessary to ensure that the requirements for both the stroke and the static boundary conditions at the edge of the mirror could be met simultaneously, but there was a significant penalty to pay in terms of bandwidth, which is inversely proportional to the square of the full mirror diameter. In a series of design iteration steps, we have created mounting arrangements that seek not only to reduce dead space, but also to improve ruggedness and temperature stability through the use of a repeatable and reliable assembly procedure. As a result, the most recently modeled mirrors display a resonance in excess of 5 kHz, combined with a maximum stroke in excess of ±10 μm. This has been achieved by virtually eliminating the "dead space" around the mirror. By careful thermal matching of the mirror and piezoelectric substrates, operation over a wide temperature range is possible. This paper will discuss the outcomes from the design study and present our initial experimental results for the most recently assembled mirror.

ATHENA: system studies and optics accommodation

NASA Astrophysics Data System (ADS)

Ayre, M.; Bavdaz, M.; Ferreira, I.; Wille, E.; Fransen, S.; Stefanescu, A.; Linder, M.

2016-07-01

ATHENA is currently in Phase A, with a view to adoption upon a successful Mission Adoption Review in 2019/2020. After a brief presentation of the reference spacecraft (SC) design, this paper will focus on the functional and environmental requirements, the thermo-mechanical design and the Assembly, Integration, Verification & Test (AIVT) considerations related to housing the Silicon Pore Optics (SPO) Mirror Modules (MM) in the very large Mirror Assembly Module (MAM). Initially functional requirements on the MM accommodation are presented, with the Effective Area and Half Energy Width (HEW) requirements leading to a MAM comprising (depending on final mirror size selected) between 700-1000 MMs, co-aligned with exquisite accuracy to provide a common focus. A preliminary HEW budget allocated across the main error-contributors is presented, and this is then used as a reference to derive subsequent requirements and engineering considerations, including: The procedures and technologies for MM-integration into the Mirror Structure (MS) to achieve the required alignment accuracies in a timely manner; stiffness requirements and handling scheme required to constrain deformation under gravity during x-ray testing; temperature control to constrain thermo-elastic deformation during flight; and the role of the Instrument Switching Mechanism (ISM) in constraining HEW and Effective Area errors. Next, we present the key environmental requirements of the MMs, and the need to minimise shock-loading of the MMs is stressed. Methods to achieve this Ø are presented, including: Selection of a large clamp-band launch vehicle interface (LV I/F); lengthening of the shock-path from the LV I/F to the MAM I/F; modal-tuning of the MAM to act as a low-pass filter during launch shock events; use of low-shock HDRMs for the MAM; and the possibility to deploy a passive vibration solution at the LV I/F to reduce loads.

Correspondence between AXAF TMA X-ray performance and models based upon mechanical and visible light measurements

NASA Technical Reports Server (NTRS)

Van Speybroeck, L.; Mckinnon, P. J.; Murray, S. S.; Primini, F. A.; Schwartz, D. A.; Zombeck, M. V.; Dailey, C. C.; Reily, J. C.; Weisskopf, M. C.; Wyman, C. L.

1986-01-01

The AXAF Technology Mirror Assembly (TMA) was characterized prior to X-ray testing by properties measured mechanically or with visible light; these include alignment offsets, roundness and global-axial-slope errors, axial-figure errors with characteristic lengths greater than about five mm, and surface roughness with scale lengths between about 0.005 and 0.5 mm. The X-ray data of Schwartz et al. (1985) are compared with predictions based upon the mechanical and visible light measurements.

Advanced X-Ray Telescope Mirrors Provide Sharpest Focus Ever

NASA Astrophysics Data System (ADS)

1997-03-01

Performing beyond expectations, the high- resolution mirrors for NASA's most powerful orbiting X-ray telescope have successfully completed initial testing at Marshall Space Flight Center's X-ray Calibration Facility, Huntsville, AL. "We have the first ground test images ever generated by the telescope's mirror assembly, and they are as good as -- or better than -- expected," said Dr. Martin Weisskopf, Marshall's chief scientist for NASA's Advanced X-ray Astrophysics Facility (AXAF). The mirror assembly, four pairs of precisely shaped and aligned cylindrical mirrors, will form the heart of NASA's third great observatory. The X-ray telescope produces an image by directing incoming X-rays to detectors at a focal point some 30 feet beyond the telescope's mirrors. The greater the percentage of X-rays brought to focus and the smaller the size of the focal spot, the sharper the image. Tests show that on orbit, the mirror assembly of the Advanced X-ray Astrophysics Facility will be able to focus approximately 70 percent of X-rays from a source to a spot less than one-half arc second in radius. The telescope's resolution is equivalent to being able to read the text of a newspaper from half a mile away. "The telescope's focus is very clear, very sharp," said Weisskopf. "It will be able to show us details of very distant sources that we know are out there, but haven't been able to see clearly." In comparison, previous X-ray telescopes -- Einstein and Rosat -- were only capable of focusing X- rays to five arc seconds. The Advanced X-ray Telescope's resolving power is ten times greater. "Images from the new telescope will allow us to make major advances toward understanding how exploding stars create and disperse many of the elements necessary for new solar systems and for life itself," said Dr. Harvey Tananbaum, director of the Advanced X- ray Astrophysics Facility Science Center at the Smithsonian Astrophysical Observatory, in Cambridge, MA -- responsible for the telescope's science mission. "We will observe X-rays generated when stars are torn apart by the incredibly strong gravity around massive black holes in the centers of galaxies," added Tananbaum. On a larger scale, the telescope will play a vital role in answering fundamental questions about the universe. "The superior quality of the mirrors will allow us to see and measure the details of hot gas clouds in clusters of galaxies, giving us a much better idea of the age and size of the universe," said Dr. Leon Van Speybroeck, Telescope Scientist at the Smithsonian Observatory. "These same observations also will measure the amount of dark matter present, providing unique insight into one of nature's great puzzles," said Van Speybroeck. A second phase of testing is now underway at Marshall. Calibration of the observatory's science instruments began in mid-February. "This phase of testing," said Weisskopf, "includes two focal plane instruments and two sets of gratings used to analyze images and energy distributions from cosmic sources seen by the telescope." Working around the clock, test teams are taking measurements and studying results. "It is very exciting," said Weisskopf. "With more than 1,200 measurements taken, there is already a tremendous amount of information for study." The calibration process will end around late April. The mirror assembly then will be shipped to TRW Space and Electronics Group, Redondo Beach, CA -- NASA's prime contractor for the program -- for integration into the spacecraft. The science instruments will remain at Marshall for several more weeks of testing before being shipped to Ball Aerospace and Technologies Corporation in Boulder, CO, where they will be integrated into the science instrument module before being shipped to TRW. The Advanced X-ray Astrophysics Facility is scheduled for launch in August 1998 and will join NASA's Hubble Space Telescope and Compton Gamma-ray Observatory in exploring the universe. Marshall manages development of the observatory for the Office of Space Science, NASA Headquarters, Washington, DC. Using glass purchased from Schott Glaswerke, Mainz, Germany, the telescope's mirrors were built by Hughes Danbury Optical Systems, Danbury, CT. The mirrors were coated by Optical Coating Laboratory, Inc., Santa Rosa, CA; and assembled by Eastman-Kodak Company, Rochester, NY. The AXAF CCD Imaging Spectrometer instrument was developed by Pennsylvania State University, University Park, and the Massachusetts Institute of Technology (MIT), Cambridge, MA. One of the two gratings was developed by MIT. The other was developed by the Space Research Organization Netherlands, Utrecht, Netherlands, in collaboration with the Max Planck Institute, Garching, Germany. The High Resolution Camera instrument was built by the Smithsonian Astrophysical Observatory. Note to editors: Digital images to accompany this release are available via the World Wide Web at the following URL: http://chandra.harvard.edu/press/images.html A photograph is available from the NASA Headquarters Audio Imaging Branch to news media to illustrate this story. The Photograph number is 97-HC-138. Photographs also are available from the Marshall Public Affairs office at 205/544-0034.

SIRTF primary mirror design, analysis, and testing

NASA Technical Reports Server (NTRS)

Sarver, George L., III; Maa, Scott; Chang, LI

1990-01-01

The primary mirror assembly (PMA) requirements and concepts for the Space Infrared Telescope Facility (SIRTF) program are discussed. The PMA studies at NASA/ARC resulted in the design of two engineering test articles, the development of a mirror mount cryogenic static load testing system, and the procurement and partial testing of a full scale spherical mirror mounting system. Preliminary analysis and testing of the single arch mirror with conical mount design and the structured mirror with the spherical mount design indicate that the designs will meet all figure and environmental requirements of the SIRTF program.

ISS-based Development of Elements and Operations for Robotic Assembly of A Space Solar Power Collector

NASA Technical Reports Server (NTRS)

Valinia, Azita; Moe, Rud; Seery, Bernard D.; Mankins, John C.

2013-01-01

We present a concept for an ISS-based optical system assembly demonstration designed to advance technologies related to future large in-space optical facilities deployment, including space solar power collectors and large-aperture astronomy telescopes. The large solar power collector problem is not unlike the large astronomical telescope problem, but at least conceptually it should be easier in principle, given the tolerances involved. We strive in this application to leverage heavily the work done on the NASA Optical Testbed Integration on ISS Experiment (OpTIIX) effort to erect a 1.5 m imaging telescope on the International Space Station (ISS). Specifically, we examine a robotic assembly sequence for constructing a large (meter diameter) slightly aspheric or spherical primary reflector, comprised of hexagonal mirror segments affixed to a lightweight rigidizing backplane structure. This approach, together with a structured robot assembler, will be shown to be scalable to the area and areal densities required for large-scale solar concentrator arrays.

The eROSITA X-ray mirrors: technology and qualification aspects of the production of mandrels, shells and mirror modules

NASA Astrophysics Data System (ADS)

Arcangeli, L.; Borghi, G.; Bräuninger, H.; Citterio, O.; Ferrario, I.; Friedrich, P.; Grisoni, G.; Marioni, F.; Predehl, P.; Rossi, M.; Ritucci, A.; Valsecchi, G.; Vernani, D.

2017-11-01

The name "eROSITA" stands for extended Roentgen Survey with an Imaging Telescope Array. The general design of the eROSITA X-ray telescope is derived from that of ABRIXAS. A bundle of 7 mirror modules with short focal lengths make up a compact telescope which is ideal for survey observations. Similar designs had been proposed for the missions DUO and ROSITA but were not realized due to programmatic shortfall. Compared to those, however, the effective area in the soft X-ray band has now much increased by adding 27 additional outer mirror shells to the original 27 ones of each mirror module. The requirement on the on-axis resolution has also been confined, namely to 15 arc seconds HEW. For these reasons the prefix "extended" was added to the original name "ROSITA". The scientific motivation for this extension is founded in the ambitious goal to detect about 100,000 clusters of galaxies which trace the large scale structure of the Universe in space and time. The X-ray telescope of eROSITA will consist of 7 identical and co-aligned mirror modules, each with 54 nested Wolter-1 mirror shells. The mirror shells are glued onto a spider wheel which is screwed to the mirror interface structure making a rigid mechanical unit. The assembly of 7 modules forms a compact hexagonal configuration with 1300 mm diameter (see Fig. 1) and will be attached to the telescope structure which connects to the 7 separate CCD cameras in the focal planes. The co-alignment of the mirror module enables eROSITA to perform also pointed observations. The replication process described in chapter III allows the manufacturing in one single piece and at the same time of both the parabola and hyperbola parts of the Wolter 1 mirror.

Design of compact off-axis four-mirror anastigmatic system for space communications

NASA Astrophysics Data System (ADS)

Zhao, Fa-cai; Sun, Quan-she; Chen, Kun-feng; Zhu, Xing-bang; Wang, Shao-shui; Wang, Guo-quan; Zheng, Xiang-liang

2013-08-01

The deployment of advanced hyperspectral imaging and other Earth sensing instruments onboard Earth observing satellites is driving the demand for high-data rate communications. Space laser communications technology offers the potential for significantly increasing in data return capability from space to Earth. Compared to the current state of the art radio frequency communications links, lasercom links operate at much higher carrier frequencies. The use of higher carrier frequencies implies a much smaller diffraction loss, which in turn, results in a much higher efficiency in delivering the signal energy. Optical communications meet the required data rates with small, low-mass, and low-power communications packages. The communications optical system assembly typically consists of a front aperture, reflection or refraction type telescope, with or without a solar rejection filter, aft optics, fine-pointing mirrors, and array detectors. Optical system used in space laser communications usually has long focal length, large aperture compared with common optical systems. So the reflective optical system is widely used. An unobstructed four-mirror anastigmatic telescope system was proposed, which was modified based on the theory about geometry optics of common-axis three-mirror systems. Intermediate image was between secondary and tertiary mirror. In order to fold the optical path, four-mirror was designed by adding the plane reflective mirror at intermediate image. The design was analyzed, then a system with effective aperture of 200mm and field of view of 1.0°x1.0° was designed, total length and magnification are 700mm and 20, respectively. The system has advantages of large magnification, relative short physical size and loose manufacturing tolerances.

A two-in-one Faraday rotator mirror exempt of active optical alignment.

PubMed

Wan, Qiong; Wan, Zhujun; Liu, Hai; Liu, Deming

2014-02-10

A two-in-one Faraday rotator mirror was presented, which functions as two independent Faraday rotation mirrors with a single device. With the introduction of a reflection lens as substitution of the mirror in traditional structure, this device is characterized by exemption of active optical alignment for the designers and manufacturers of Faraday rotator mirrors. A sample was fabricated by passive mechanical assembly. The insertion loss was measured as 0.46 dB/0.50 dB for the two independent ports, respectively.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-01-01

This photograph shows the mirrors of the High Resolution Mirror Assembly (HRMA) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being assembled in the Eastman Kodak Company in Rochester, New York. The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRMA, the heart of the telescope system, is contained in the cylindrical "telescope" portion of the observatory. Since high-energy x-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets of four nested mirrors resemble tubes within tubes. Incoming x-rays graze off the highly polished mirror surface and are furneled to the instrument section for detection and study. TRW, Inc. was the prime contractor for the development of the CXO and NASA's Marshall Space Flight Center was responsible for its project management. The Observatory was launched July 22, 1999 aboard the Space Shuttle Columbia, STS-93 mission.

Dual-use bimorph deformable mirrors

NASA Astrophysics Data System (ADS)

Griffith, M. S.; Laycock, L. C.; Bagshaw, J. M.; Rowe, D.

2005-11-01

Adaptive Optics (AO) is a critical underpinning technology for future optical countermeasures, laser delivery, target illumination and imaging systems. It measures and compensates for optical distortion caused by transmission through the atmosphere, resulting in the ability to deploy smaller lasers and identify targets at greater ranges. AO is also well established in ground based astronomy, and is finding applications in free space optical communications and ophthalmology. One of the key components in an AO system is the wavefront modifier, which acts on the incoming or outgoing beam to counter the effects of the atmosphere. BAE SYSTEMS ATC is developing multi-element Deformable Bimorph Mirrors (DBMs) for such applications. A traditional bimorph deformable mirror uses a set of edge electrodes outside the active area in order to meet the required boundary conditions for the active aperture. This inflicts a significant penalty in terms of bandwidth, which is inversely proportional to the square of the full mirror diameter. We have devised a number of novel mounting arrangements that reduce dead space and thus provide a much improved trade-off between bandwidth and stroke. These schemes include a novel method for providing vertical displacement at the periphery of the aperture, a method for providing a continuous compliant support underneath the bimorph mirror, and a method for providing a three point support underneath the bimorph. In all three cases, there is no requirement for edge electrodes to provide the boundary conditions, resulting in devices of much higher bandwidth. The target is to broaden the use of these types of mirror beyond the current limits of either low order/low bandwidth, to address the high order, high bandwidth systems required by long range, horizontal path applications. This paper will discuss the different mirror designs, and present experimental results for the most recently assembled mirrors.

Thematic mapper flight model preshipment review data package. Volume 4: Appendix. Part B: Scan mirror assembly data

NASA Technical Reports Server (NTRS)

1982-01-01

Data from the thematic mapper scan mirror assembly (SMA) acceptance test are presented. Documentation includes: (1) a list of the acceptance test discrepancies; (2) flight 1 SMA test data book; (3) flight 1 SMA environmental report; (4) the configuration verification index; (5) the flight 1 SMA test failure reports; (6) the flight 1 data tapes log; and (7) the requests for deviation/waivers.

Next Generation X-Ray Optics: High-Resolution, Light-Weight, and Low-Cost

NASA Technical Reports Server (NTRS)

Zhang, William W.

2012-01-01

X-ray telescopes are essential to the future of x-ray astronomy. In this talk I will describe a comprehensive program to advance the technology for x-ray telescopes well beyond the state of the art represented by the three currently operating missions: Chandra, XMM-Newton, and Suzaku. This program will address the three key issues in making an x-ray telescope: (1) angular resolution, (2) effective area per unit mass, and (3) cost per unit effective area. The objectives of this technology program are (1) in the near term, to enable Explorer-class x-ray missions and an IXO-type mission, and (2) in the long term, to enable a flagship x-ray mission with sub-arcsecond angular resolution and multi-square-meter effective area, at an affordable cost. We pursue two approaches concurrently, emphasizing the first approach in the near term (2-5 years) and the second in the long term (4-10 years). The first approach is precision slumping of borosilicate glass sheets. By design and choice at the outset, this technique makes lightweight and low-cost mirrors. The development program will continue to improve angular resolution, to enable the production of 5-arcsecond x-ray telescopes, to support Explorer-class missions and one or more missions to supersede the original IXO mission. The second approach is precision polishing and light-weighting of single-crystal silicon mirrors. This approach benefits from two recent commercial developments: (1) the inexpensive and abundant availability of large blocks of monocrystalline silicon, and (2) revolutionary advances in deterministic, precision polishing of mirrors. By design and choice at the outset, this technique is capable of producing lightweight mirrors with sub-arcsecond angular resolution. The development program will increase the efficiency and reduce the cost of the polishing and the light-weighting processes, to enable the production of lightweight sub-arcsecond x-ray telescopes. Concurrent with the fabrication of lightweight mirror segments is the continued development and perfection of alignment and integration techniques, for incorporating individual mirror segments into a precision mirror assembly. Recently, we have been developing a technique called edge-bonding, which has achieved an accuracy to enable 10-arcsecond x-ray telescopes. Currently, we are investigating and improving the long-term alignment stability of so-bonded mirrors. Next, we shall refine this process to enable 5-arsecond x-ray telescopes. This technology development program includes all elements to demonstrate progress toward TRL-6: metrology; x-ray performance tests; coupled structural, thermal, and optical performance analysis, and environmental testing.

Next Generation X-Ray Optics: High-Resolution, Light-Weight, and Low-Cost

NASA Technical Reports Server (NTRS)

Zhang, William W.

2011-01-01

X-ray telescopes are essential to the future of x-ray astronomy. This paper describes a comprehensive program to advance the technology for x-ray telescopes well beyond the state of the art represented by the three currently operating missions: Chandra, XMM-Newton , and Suzaku . This program will address the three key issues in making an x-ray telescope: (I) angular resolution, (2) effective area per unit mass, and (3) cost per unit effective area. The objectives of this technology program are (1) in the near term, to enable Explorer-class x-ray missions and an IXO type mission, and (2) in the long term, to enable a flagship x-ray mission with sub-arcsecond angular resolution and multi-square-meter effective area, at an affordable cost. We pursue two approaches concurrently, emphasizing the first approach in the near term (2-5 years) and the second in the long term (4-10 years). The first approach is precision slumping of borosilicate glass sheets. By design and choice at the outset, this technique makes lightweight and low-cost mirrors. The development program will continue to improve angular resolution, to enable the production of 5-arcsecond x-ray telescopes, to support Explorer-class missions and one or more missions to supersede the original IXO mission. The second approach is precision polishing and light-weighting of single-crystal silicon mirrors. This approach benefits from two recent commercial developments: (1) the inexpensive and abundant availability of large blocks of mono crystalline silicon, and (2) revolutionary advances in deterministic, precision polishing of mirrors. By design and choice at the outset, this technique is capable of producing lightweight mirrors with sub-arcsecond angular resolution. The development program will increase the efficiency and reduce the cost of the polishing and the lightweighting processes, to enable the production of lightweight sub-arcsecond x-ray telescopes. Concurrent with the fabrication of lightweight mirror segments is the continued development and perfection of alignment and integration techniques, for incorporating individual mirror segments into a precision mirror assembly. Recently, we have been developing a technique called edge-bonding, which has achieved an accuracy to enable 10- arcsecond x-ray telescopes. Currently, we are investigating and improving the long-term alignment stability of so-bonded mirrors. Next, we shall refine this process to enable 5-arsecond x-ray telescopes. This technology development program includes all elements to demonstrate progress toward TRL-6: metrology; x-ray performance tests; coupled structural, thermal, and optical performance analysis, and environmental testing.

Ultralightweight optics for space applications

NASA Astrophysics Data System (ADS)

Mayo, James W.; DeHainaut, Linda L.; Bell, Kevin D.; Smith, Winfred S.; Killpatrick, Don H.; Dyer, Richard W.

2000-07-01

Lightweight, deployable space optics has been identified as a key technology for future cost-effective, space-based systems. The United States Department of Defense has partnered with the National Aeronautical Space Administration to implement a space mirror technology development activity known as the Advanced Mirror System Demonstrator (AMSD). The AMSD objectives are to advance technology in the production of low-mass primary mirror systems, reduce mirror system cost and shorten mirror- manufacturing time. The AMSD program will offer substantial weight, cost and production rate improvements over Hubble Space Telescope mirror technology. A brief history of optical component development and a review of optical component state-of-the-art technology will be given, and the AMSD program will be reviewed.

Multi-link laser interferometer architecture for a next generation GRACE

NASA Astrophysics Data System (ADS)

Francis, Samuel Peter

When GRACE Follow-On (GRACE-FO) launches, it will be the first time a laser interferometer has been used to measure displacement between spacecraft. In the future, interspacecraft laser interferometry will be used in LISA, a space-based gravitational wave detector, that requires the change in separation between three spacecraft to be measured with a resolution of 1 pm/rtHz. The sensitivity of an interspacecraft interferometer is potentially limited by spacecraft degrees-of-freedom, such as rotation, coupling into the interspacecraft displacement measurement. GRACE-FO and LISA therefore have strict requirements placed on the positioning and alignment of the interferometers during spacecraft integration. Decades of work has gone into adapting traditionally lab-based techniques for these space applications. As an example, GRACE-FO stops rotation of the two spacecraft from coupling into displacement using the triple mirror assembly. The triple mirror assembly is a precision optic, comprised of three mirrors, that function as a retroreflector. Provided the triple mirror assembly vertex coincides with the spacecraft centre of mass, any spacecraft rotation will asymmetrically lengthen and shorten the optical pathlengths of the incoming and outgoing beams, ensuring that the round trip pathlength between the spacecraft is unaffected. To achieve the required displacement sensitivity, the triple mirror assembly vertex must be positioned within 0.5 mm of the spacecraft centre of mass, making spacecraft integration challenging. In this thesis a new, all-fibre interferometer architecture is presented that aims to simplify the positioning and alignment of space-based interferometers. Using multiple interspacecraft link measurements and high-speed signal processing the interspacecraft displacement is synthesised in post-processing. The multi-link interferometry concept is similar to the triple mirror assembly's symmetric suppression of rotation, however, since the rotation-to-pathlength cancellation is performed in post-processing, the weighting of each interspacecraft link measurement can be optimised to completely cancel any rotation coupled error. Consequently, any uncertainty in the positioning of the multi-link interferometer during spacecraft integration can be corrected for in post-processing. The strict hardware integration requirements of current interferometers can therefore be relaxed, enabling a new class of simpler, cheaper missions. (Abstract shortened by ProQuest.).

Metrology for Trending Alignment of the James Webb Space Telescope Before and After Ambient Environmental Testing

NASA Technical Reports Server (NTRS)

Hadjimichael, Theo; Ohl, Raymond G.; Berrier, Joshua; Gum, Jeffery; Hayden, Joseph; Khreishi, Manal; McLean, Kyle; Redman, Kevin; Sullivan, Joseph; Wenzel, Greg;

Metrology for Trending Alignment of the James Webb Space Telescope Before and After Ambient Environmental Testing

NASA Technical Reports Server (NTRS)

Hadjimichael, Theo; Ohl, Raymond G.; Berrier, Joshua; Gum, Jeff; Hayden, Joseph; Khreishi, Manal; Mclean, Kyle; Redman, Kevin; Sullivan, Joseph; Wenzel, Greg;

MEMS micromirrors for optical switching in multichannel spectrophotometers

NASA Astrophysics Data System (ADS)

Tuantranont, Adisorn; Lomas, Tanom; Bright, Victor M.

2004-04-01

This paper reports for the first time that a novel MEMS-based micromirror switch has successfully demonstrated for optical switching in a multi-channel fiber optics spectrophotometer system. The conventional optomechanical fiber optic switches for multi-channel spectrophotometers available in market are bulky, slow, low numbers of channels and expensive. Our foundry MEMS-based micromirror switch designed for integrating with commercially available spectrophotometers offers more compact devices, increased number of probing channels, higher performance and cheaper. Our MEMS-based micromirror switch is a surface micromachined mirror fabricated through MUMPs foundry. The 280 μm x 280 μm gold coated mirror is suspended by the double-gimbal structure for X and Y axis scanning. Self-assembly by solders is used to elevate the torsion mirror 30 μm over the substrate to achieve large scan angle. The solder self-assembly approach dramatically reduces the time to assembly the switch. The scan mirror is electrostatically controlled by applying voltages. The individual probing signal from each probing head is guided by fibers with collimated lenses and incidents on the center of the mirror. The operating scan angle is in the range of 3.5 degrees with driving voltage of 0-100 V. The fastest switching time of 4 millisecond (1 ms rise time and 3 ms fall time) is measured corresponding to the maximum speed of the mirror of 0.25 kHz when the mirror is scanning at +/- 1.5 degrees. The micromirror switch is packaged with a multi-mode fiber bundle using active alignment technique. A centered fiber is the output fiber that is connected to spectrophotometer. Maximum insertion loss of 5 dB has been obtained. The accuracy of measured spectral data is equivalent to the single channel spectrophotometer with a small degradation on probing signal due to fiber coupling.

Direct hot slumping and accurate integration process to manufacture prototypal x-ray optical units made of glass

NASA Astrophysics Data System (ADS)

Civitani, M.; Ghigo, M.; Basso, S.; Proserpio, L.; Spiga, D.; Salmaso, B.; Pareschi, G.; Tagliaferri, G.; Burwitz, V.; Hartner, G.; Menz, B.; Bavdaz, M.; Wille, E.

2013-09-01

X-ray telescopes with very large collecting area, like the proposed International X-ray Observatory (IXO, with around 3 m2 at 1 keV), need to be composed of a large number high quality mirror segments, aiming at achieving an angular resolution better than 5 arcsec HEW (Half-Energy-Width). A possible technology to manufacture the modular elements that will compose the entire optical module, named X-ray Optical Units (XOUs), consists of stacking in Wolter-I configuration several layers of thin foils of borosilicate glass, previously formed by hot slumping. The XOUs are subsequently assembled to form complete multi-shell optics with Wolter-I geometry. The achievable global angular resolution of the optic relies on the required surface shape accuracy of slumped foils, on the smoothness of the mirror surfaces and on the correct integration and co-alignment of the mirror segments. The Brera Astronomical Observatory (INAF-OAB) is leading a study, supported by ESA, concerning the implementation of the IXO telescopes based on thin slumped glass foils. In addition to the opto-mechanical design, the study foresees the development of a direct hot slumping thin glass foils production technology. Moreover, an innovative assembly concept making use of Wolter-I counter-form moulds and glass reinforcing ribs is under development. The ribs connect pairs of consecutive foils in an XOU stack, playing a structural and a functional role. In fact, as the ribs constrain the foil profile to the correct shape during the bonding, they damp the low-frequency profile errors still present on the foil after slumping. A dedicated semirobotic Integration MAchine (IMA) has been realized to this scope and used to build a few integrated prototypes made of several layers of slumped plates. In this paper we provide an overview of the project, we report the results achieved so far, including full illumination intra-focus X-ray tests of the last integrated prototype that are compliant with a HEW of around 17''.

Manufacturing and control of the aspherical mirrors for the telescope of the satellite Pleiades

NASA Astrophysics Data System (ADS)

Ducollet, Hélène; du Jeu, Christian; Fermé, Jean-Jacques

2017-11-01

For the Pleiades space program, SESO has been awarded the contract (fully completed), for the manufacturing of the whole set of telescope mirrors (4 mirrors, 2 flight models). These works did also include the mechanical design, manufacturing and mounting of the attachment flexures between the mirrors and the telescope main structure. This presentation is focused on the different steps of lightweighting, polishing, integration and control of these mirrors as well as a presentation of the existing SESO facilities and capabilities to produce such kind of aspherical components/sub-assemblies.

High stroke pixel for a deformable mirror

DOEpatents

Miles, Robin R.; Papavasiliou, Alexandros P.

2005-09-20

A mirror pixel that can be fabricated using standard MEMS methods for a deformable mirror. The pixel is electrostatically actuated and is capable of the high deflections needed for spaced-based mirror applications. In one embodiment, the mirror comprises three layers, a top or mirror layer, a middle layer which consists of flexures, and a comb drive layer, with the flexures of the middle layer attached to the mirror layer and to the comb drive layer. The comb drives are attached to a frame via spring flexures. A number of these mirror pixels can be used to construct a large mirror assembly. The actuator for the mirror pixel may be configured as a crenellated beam with one end fixedly secured, or configured as a scissor jack. The mirror pixels may be used in various applications requiring high stroke adaptive optics.

JWST testbed telescope: a functionally accurate scaled version of the flight optical telescope element used to develop the flight wavefront sensing and control algorithm

NASA Astrophysics Data System (ADS)

Kingsbury, Lana K.; Atcheson, Paul D.

2004-10-01

The Northrop-Grumman/Ball/Kodak team is building the JWST observatory that will be launched in 2011. To develop the flight wavefront sensing and control (WFS&C) algorithms and software, Ball is designing and building a 1 meter diameter, functionally accurate version of the JWST optical telescope element (OTE). This testbed telescope (TBT) will incorporate the same optical element control capability as the flight OTE. The secondary mirror will be controlled by a 6 degree of freedom (dof) hexapod and each of the 18 segmented primary mirror assemblies will have 6 dof hexapod control as well as radius of curvature adjustment capability. In addition to the highly adjustable primary and secondary mirrors, the TBT will include a rigid tertiary mirror, 2 fold mirrors (to direct light into the TBT) and a very stable supporting structure. The total telescope system configured residual wavefront error will be better than 175 nm RMS double pass. The primary and secondary mirror hexapod assemblies enable 5 nm piston resolution, 0.0014 arcsec tilt resolution, 100 nm translation resolution, and 0.04497 arcsec clocking resolution. The supporting structure (specifically the secondary mirror support structure) is designed to ensure that the primary mirror segments will not change their despace position relative to the secondary mirror (spaced > 1 meter apart) by greater than 500 nm within a one hour period of ambient clean room operation.

Overview of deformable mirror technologies for adaptive optics and astronomy

NASA Astrophysics Data System (ADS)

Madec, P.-Y.

2012-07-01

From the ardent bucklers used during the Syracuse battle to set fire to Romans’ ships to more contemporary piezoelectric deformable mirrors widely used in astronomy, from very large voice coil deformable mirrors considered in future Extremely Large Telescopes to very small and compact ones embedded in Multi Object Adaptive Optics systems, this paper aims at giving an overview of Deformable Mirror technology for Adaptive Optics and Astronomy. First the main drivers for the design of Deformable Mirrors are recalled, not only related to atmospheric aberration compensation but also to environmental conditions or mechanical constraints. Then the different technologies available today for the manufacturing of Deformable Mirrors will be described, pros and cons analyzed. A review of the Companies and Institutes with capabilities in delivering Deformable Mirrors to astronomers will be presented, as well as lessons learned from the past 25 years of technological development and operation on sky. In conclusion, perspective will be tentatively drawn for what regards the future of Deformable Mirror technology for Astronomy.

Design of spatial oval plane mirror and its support structure

NASA Astrophysics Data System (ADS)

Chai, Wenyi; Hu, Yongming; Wang, Chenjie; Chen, Su; Feng, Song

2018-02-01

For the diameter of 150mm elliptical flat mirror that used in the space, selected the zerodur material and a lightweight design is conducted in the way of selected back-open-architecture with symmetrical axisymmetric arrangement, and in order to evaluate the effect of thermal stress from -10°C to 45°C on the mirror, a reflection mirror is designed based on the multipoint flexible support. The mirror component's mechanic and thermodynamic characteristics is analyzed with the simulation software, the support structure parameters are optimized, that can be used to evaluate the effect of gravity, assembly stress, and thermal stress load on mirror, while ensuring the component's stiffness and strength. According to the design condition developed a product and carried out mechanic and thermodynamic environment, the product could meet the shape accuracy PV λ/3, RMS λ/30 in the condition of thermodynamic environment, and the shape accuracy PV λ/5, RMS λ/40 in the condition of ground gravity and assembly stress (λ=632.8nm), while the product can withstand with the mechanical oscillation environment sinusoidal oscillation 10g, RMS random oscillation acceleration 14.4g.

Optical system for UV-laser technological equipment

NASA Astrophysics Data System (ADS)

Fedosov, Yuri V.; Romanova, Galina E.; Afanasev, Maxim Ya.

2017-09-01

Recently there has been an intensive development of intelligent industrial equipment that is highly automated and can be rapidly adjusted for certain details. This equipment can be robotics systems, automatic wrappers and markers, CNC machines and 3D printers. The work equipment considered is the system for selective curing of photopolymers using a UV-laser and UV-radiation in such equipment that leads to additional technical difficulties. In many cases for transporting the radiation from the laser to the point processed, a multi-mirror system is used: however, such systems are usually difficult to adjust. Additionally, such multi-mirror systems are usually used as a part of the equipment for laser cutting of metals using high-power IR-lasers. For the UV-lasers, using many mirrors leads to crucial radiation losses because of many reflections. Therefore, during the development of the optical system for technological equipment using UV-laser we need to solve two main problems: to transfer the radiation for the working point with minimum losses and to include the system for controlling/handling the radiation spot position. We introduce a system for working with UV-lasers with 450mW of power and a wavelength of 0.45 μm based on a fiber system. In our modelling and design, we achieve spot sizes of about 300 μm, and the designed optical and mechanical systems (prototypes) were manufactured and assembled. In this paper, we present the layout of the technological unit, the results of the theoretical modelling of some parts of the system and some experimental results.

Optical System Design for the Next Generation Space Telescope

NASA Technical Reports Server (NTRS)

Solomon, Leonard H. (Principal Investigator); Kahan, Mark A.

1996-01-01

This report provides considerations and suggested approaches for design of the Optical Telescope Assembly and the segmented primary mirror of a Next Generation Space Telescope (NGST). Based on prior studies and hardware development, we provide data and design information on low-risk materials and hardware configurations most likely to meet low weight, low temperature and long-life requirements of the nominal 8-meter aperture NGST. We also provide preliminary data for cost and performance trades, and recommendations for technology development and demonstration required to support the system design effort.

Lightweight Zerodur Mirror Technology

DTIC Science & Technology

1982-10-01

17 September 1981 Contract Expiration Date: 15 May 1982 Short Title of Work: Lightweight Zerodur Mirror Technology Program Code Number: 1LIO Period of...iepRA LIGHTWEIGHT ZERODUR MIRROR TECHNOLOGY 21 Sep 81 - 21 May 82 1. PERFORMING 0,10. REPORT NUMWERn 15512 7: AUTHOR(*J S. CONTRACT OR GRANT NUMSER[JlII...1S. KIEV WORDS (Continue on reverse aide If necesery 1nd Identify b? block nwi nhm ) Zerodur Lightweight Mirrors Mirror Blank Fabrication Frit

DIVA optical telescope

NASA Astrophysics Data System (ADS)

Graue, Roland; Kampf, Dirk; Röser, Siegfried; Bastian, Ulrich; Seifert, Walter

2003-02-01

The German Instrument for Multi-channel Photometry and Astrometry (DIVA), dedicated to the German (DLR) small extraterrestrial satellite program, is intended as a kind of technology precursor mission to GAIA. DIVA is scheduled for launch in 2004 and shall perform a sky survey to measure within 2 years life time the positions, parallaxes, magnitudes, etc. of about 35 million stars. The main instrument, covering the spectral range of 400-1000nm, observes 2 fields of view (0.6° x 0.77°) by a single Focal Plane Assembly (FPA). The focal length is 11200mm. The DIVA Optomechanics is based on a high precision Three Mirror Anastigmat (TMA) concept with 8 mirrors, 5 of them flat. An extremely high short term stability (torsion tolerance) of 0.3 mas over 10h only has to be realized only by passive means to achieve the astrometrical performance requirements. The paper describes the phase B2 design activities wrt. the optomechanical and thermal design of the main instrument. Special emphasis is given to an exhausting, but very pragmatic thermomechanical and optical performance trade off between a cost effective athermal design concept, applying mirrors and an optical bench made from a specially treated isotropic aluminum alloy, and a thermally stable hybrid material concept based on a Carbon Fiber Reinforced Plastics (CFRP) sandwich structure and Zerodur mirrors. The selection of the final baseline design solution shall be reported. According to the very high long and short scale surface properties of the candidate aluminum mirrors a sophisticated manufacturing procedure was established based on conventional and ion beam polishing techniques. The representative breadboard mirror test results will be given.

A conceptual scheme for cophasing across gaps in segmented pupils with a laser guide star Fizeau interferometer

NASA Astrophysics Data System (ADS)

Tuthill, Peter

2016-08-01

Finding and maintaining an accurate cophasing solution for the large primary mirrors which comprise the coming generation of Extremely Large Telescopes has required a significant technological development effort that is still ongoing. Mirrors based on an assembly of a few large segments, such as the Giant Magellan Telescope (GMT - under construction) and the Large Binocular Telescope (LBT - operational) face a particular challenge: elements must be cophased across a gaps ranging from tens of centimeters to meters. Although it is widely believed that laser guide stars are not useful for this specific application, this paper advances a new concept that challenges this orthodoxy. By projecting a Fizeau interference pattern into the sky, and analyzing the form of the backscattered image, it is shown that at least in principle it is possible to cophase across arbitrary gaps.

Status of Technology Development to enable Large Stable UVOIR Space Telescopes

NASA Astrophysics Data System (ADS)

Stahl, H. Philip; MSFC AMTD Team

2017-01-01

NASA MSFC has two funded Strategic Astrophysics Technology projects to develop technology for potential future large missions: AMTD and PTC. The Advanced Mirror Technology Development (AMTD) project is developing technology to make mechanically stable mirrors for a 4-meter or larger UVOIR space telescope. AMTD is demonstrating this technology by making a 1.5 meter diameter x 200 mm thick ULE(C) mirror that is 1/3rd scale of a full size 4-m mirror. AMTD is characterizing the mechanical and thermal performance of this mirror and of a 1.2-meter Zerodur(R) mirror to validate integrate modeling tools. Additionally, AMTD has developed integrated modeling tools which are being used to evaluate primary mirror systems for a potential Habitable Exoplanet Mission and analyzed the interaction between optical telescope wavefront stability and coronagraph contrast leakage. Predictive Thermal Control (PTC) project is developing technology to enable high stability thermal wavefront performance by using integrated modeling tools to predict and actively control the thermal environment of a 4-m or larger UVOIR space telescope.

A soft actuation system for segmented reflector articulation and isolation

NASA Technical Reports Server (NTRS)

Agronin, Michael L.; Jandura, Louise

1990-01-01

Segmented reflectors have been proposed for space based applications such as optical communication and large diameter telescopes. An actuation system for mirrors in a space based segmented mirror array was developed as part of NASA's Precision Segmented Reflector program. The actuation system, called the Articulated Panel Module (APM), provides 3 degrees of freedom mirror articulation, gives isolation from structural motion, and simplifies space assembly of the mirrors to the reflector backup truss. A breadboard of the APM was built and is described.

Preparation of Plasmonic Platforms of Silver Wires on Gold Mirrors and Their Application to Surface Enhanced Fluorescence

PubMed Central

2015-01-01

In this report we describe a preparation of silver wires (SWs) on gold mirrors and its application to surface enhanced fluorescence (SEF) using a new methodology. Silica protected gold mirrors were drop-coated with a solution of silver triangular nanoprisms. The triangular nanoprisms were slowly air-dried to get silver wires that self-assembled on the gold mirrors. Fluorescence enhancement was studied using methyl azadioxatriangulenium chloride (Me-ADOTA·Cl) dye in PVA spin-coated on a clean glass coverslip. New Plasmonic Platforms (PPs) were assembled by placing a mirror with SWs in contact with a glass coverslip spin-coated with a uniform Me-ADOTA·Cl film. It was shown that surface enhanced fluorescence is a real phenomenon, not just an enhancement of the fluorescence signal due to an accumulation of the fluorophore on rough nanostructure surfaces. The average fluorescence enhancement was found to be about 15-fold. The lifetime of Me-ADOTA·Cl dye was significantly reduced (∼4 times) in the presence of SWs. Moreover, fluorescence enhancement and lifetime did not show any dependence on the excitation light polarization. PMID:25296293

Heterogeneous MEMS Device Assembly and Integration

DTIC Science & Technology

2014-04-01

included a camera, a He-Ne laser, attenuation filters, folding mirrors, the micromirror under test (MUT) and the observation plane. The MUT was...non activated mirror (the initial incidence plane) was horizontal. Figure 4: Micromirror characterization setup. The static response of a beam

LDR segmented mirror technology assessment study

NASA Technical Reports Server (NTRS)

Krim, M.; Russo, J.

1983-01-01

In the mid-1990s, NASA plans to orbit a giant telescope, whose aperture may be as great as 30 meters, for infrared and sub-millimeter astronomy. Its primary mirror will be deployed or assembled in orbit from a mosaic of possibly hundreds of mirror segments. Each segment must be shaped to precise curvature tolerances so that diffraction-limited performance will be achieved at 30 micron (nominal operating wavelength). All panels must lie within 1 micron on a theoretical surface described by the optical precipitation of the telescope's primary mirror. To attain diffraction-limited performance, the issues of alignment and/or position sensing, position control of micron tolerances, and structural, thermal, and mechanical considerations for stowing, deploying, and erecting the reflector must be resolved. Radius of curvature precision influences panel size, shape, material, and type of construction. Two superior material choices emerged: fused quartz (sufficiently homogeneous with respect to thermal expansivity to permit a thin shell substrate to be drape molded between graphite dies to a precise enough off-axis asphere for optical finishing on the as-received a segment) and a Pyrex or Duran (less expensive than quartz and formable at lower temperatures). The optimal reflector panel size is between 1-1/2 and 2 meters. Making one, two-meter mirror every two weeks requires new approaches to manufacturing off-axis parabolic or aspheric segments (drape molding on precision dies and subsequent finishing on a nonrotationally symmetric dependent machine). Proof-of-concept developmental programs were identified to prove the feasibility of the materials and manufacturing ideas.

JEUMICO: Czech-Bavarian astronomical X-ray optics project

NASA Astrophysics Data System (ADS)

Hudec, R.; Döhring, T.

2017-07-01

Within the project JEUMICO, an acronym for "Joint European Mirror Competence", the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague started a collaboration to develop mirrors for X-ray telescopes. Corresponding mirror segments use substrates of flat silicon wafers which are coated with thin iridium films, as this material is promising high reflectivity in the X-ray range of interest. The sputtering parameters are optimized in the context of the expected reflectivity of the coated X-ray mirrors. In near future measurements of the assembled mirror modules optical performances are planned at an X-ray test facility.

Advances in Strapdown Sensors

DTIC Science & Technology

1984-04-01

axis laser gyro sensor assembly (1, 24) in a single Zerodur structure using interleaved laser paths to reduce net size/weight. If advances in mirror ...laser gyros, special design considerations - associated with mechanically dithered laaer gyros, the state-of-the-art in magnetic mirror and...from the lasing action of a helium-noon gas discharge within the optical cavity. The reflecting surfaces are die- lectric mirrors designed to

Silicon Carbide Technologies for Lightweighted Aerospace Mirrors

DTIC Science & Technology

2008-09-01

Silicon Carbide Technologies for Lightweighted Aerospace Mirrors Lawrence E. Matson (1) Ming Y. Chen (1) Brett deBlonk (2) Iwona A...glass and beryllium to produce lightweighted aerospace mirror systems has reached its limits due to the long lead times, high processing costs...for making mirror structural substrates, figuring and finishing technologies being investigated to reduce cost time and cost, and non-destructive

Improvements in analysis techniques for segmented mirror arrays

NASA Astrophysics Data System (ADS)

Michels, Gregory J.; Genberg, Victor L.; Bisson, Gary R.

2016-08-01

The employment of actively controlled segmented mirror architectures has become increasingly common in the development of current astronomical telescopes. Optomechanical analysis of such hardware presents unique issues compared to that of monolithic mirror designs. The work presented here is a review of current capabilities and improvements in the methodology of the analysis of mechanically induced surface deformation of such systems. The recent improvements include capability to differentiate surface deformation at the array and segment level. This differentiation allowing surface deformation analysis at each individual segment level offers useful insight into the mechanical behavior of the segments that is unavailable by analysis solely at the parent array level. In addition, capability to characterize the full displacement vector deformation of collections of points allows analysis of mechanical disturbance predictions of assembly interfaces relative to other assembly interfaces. This capability, called racking analysis, allows engineers to develop designs for segment-to-segment phasing performance in assembly integration, 0g release, and thermal stability of operation. The performance predicted by racking has the advantage of being comparable to the measurements used in assembly of hardware. Approaches to all of the above issues are presented and demonstrated by example with SigFit, a commercially available tool integrating mechanical analysis with optical analysis.

Assembly of NASA's Most Powerful X-Ray Telescope Completed

NASA Astrophysics Data System (ADS)

1998-03-01

Assembly of the world's most powerful X-ray telescope, NASA's Advanced X-ray Astrophysics Facility, was completed last week with the installation of its power-generating twin solar panels. The observatory is scheduled for launch aboard Space Shuttle mission STS-93, in December 1998. The last major components of the observatory were bolted and pinned into place March 4 at TRW Space & Electronics Group in Redondo Beach, Calif., and pre-launch testing of the fully assembled observatory began March 7. "Completion of the observatory's assembly process is a big step forward toward launch scheduled for the end of this year," said Fred Wojtalik, manager of the Observatory Projects Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "With all the major components in place, we are now concentrating on a thorough pre-launch checkout of the observatory." "We're delighted to reach this major milestone for the program," said Craig Staresinich, TRW's Advanced X-ray Astrophysics Facility program manager. "The entire observatory team has worked hard to get to this point and will continue an exhaustive test program to ensure mission success. We're looking forward to delivering a truly magnificent new space capability to NASA later this summer." The first pre-launch test of the Advanced X-ray Astrophysics Facility was an acoustic test, which simulated the sound pressure environment inside the Space Shuttle cargo bay during launch. A thorough electrical checkout before and after the acoustic test verifies that the observatory and its science instruments can withstand the extreme sound levels and vibrations that accompany launch. "With 10 times the resolution and 50-100 times the sensitivity of any previous X-ray telescope, this observatory will provide us with a new perspective of our universe," said the project's chief scientist, Dr. Martin Weisskopf of Marshall Center. "We'll be able to study sources of X-rays throughout the universe, like colliding galaxies and black holes, many of which are invisible to us now. We may even see the processes that create the elements found here on Earth." Assembly of the observatory began in 1997 with the arrival of the high resolution mirror assembly at TRW Space and Electronics Group. In August 1997, the telescope's optical bench was mated with the mirrors, followed by integration of the telescope with the spacecraft in October. In February 1998, the observatory's science instrument module was mated to the top of the telescope. The complete observatory is 45 feet long, has a solar array wing span 64 feet wide, and weighs more than 5 tons. Using glass purchased from Schott Glaswerke, Mainz, Germany, the telescope's mirrors were built by Raytheon Optical Systems Inc., Danbury, Conn. The mirrors were coated by Optical Coating Laboratory Inc., Santa Rosa, Calif.; and assembled by Eastman-Kodak Co., Rochester, N.Y. The observatory's charged coupled device imaging spectrometer was developed by Pennsylvania State University at University Park, and the Massachusetts Institute of Technology (MIT), at Cambridge. One diffraction grating was developed by MIT, the other by the Space Research Organization Netherlands, Utrecht, in collaboration with the Max Planck Institute, Garching, Germany. The high resolution camera instrument was built by the Smithsonian Astrophysical Observatory. Ball Aerospace & Technologies Corporation of Boulder, Colo., developed the science instrument module. The Advanced X-ray Astrophysics Facility program is managed by the Marshall Center for the Office of Space Science, NASA Headquarters, Washington, D.C. The Smithsonian Astrophysical Observatory in Cambridge, Mass., will operate the observatory for NASA. NOTE TO EDITORS: A photo of the integrated telescope is available via the World Wide Web at URL: http://chandra.harvard.edu/press/images.html Prepared by John Bryk

Experimental study of an off-axis three mirror anastigmatic system with wavefront coding technology.

PubMed

Yan, Feng; Tao, Xiaoping

2012-04-10

Wavefront coding (WFC) is a kind of computational imaging technique that controls defocus and defocus related aberrations of optical systems by introducing a specially designed phase distribution to the pupil function. This technology has been applied in many imaging systems to improve performance and/or reduce cost. The application of WFC technology in an off-axis three mirror anastigmatic (TMA) system has been proposed, and the design and optimization of optics, the restoration of degraded images, and the manufacturing of wavefront coded elements have been researched in our previous work. In this paper, we describe the alignment, the imaging experiment, and the image restoration of the off-axis TMA system with WFC technology. The ideal wavefront map is set to be the system error of the interferometer to simplify the assembly, and the coefficients of certain Zernike polynomials are monitored to verify the result in the alignment process. A pinhole of 20 μm diameter and the third plate of WT1005-62 resolution patterns are selected as the targets in the imaging experiment. The comparison of the tail lengths of point spread functions is represented to show the invariance of the image quality in the extended depth of focus. The structure similarity is applied to estimate the relationship among the captured images with varying defocus. We conclude that the experiment results agree with the earlier theoretical analysis.

Managing Risk on a Technology Development Project/Advanced Mirror System Demonstrator

NASA Technical Reports Server (NTRS)

Byberg, Alicia; Russell, J. Kevin; Stahl, Phil (Technical Monitor)

2002-01-01

The risk management study applied to the Advanced Mirror System Demonstrator (AMSD), a precursor mirror technology development for the Next Generation Space Telescope (NGST) is documented. The AMSD will be developed as a segment of a lightweight primary mirror system that can be produced at a low cost and with a short manufacturing schedule. The technology gained from the program will support the risk mitigation strategy for the NGST, as well as other government agency space mirror programs.

JWST Primary Mirror Technology Development

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2010-01-01

Mirror Technology was identified as a (if not the) critical capability necessary to achieve the Level 1 science goals. A never before demonstrated space telescope capability was required: 6 to 8 meter class pri mary mirror, diffraction limited at 2 micrometers and operates at temperatures below 50K. Launch vehicle constraints placed significant architectural constraints: deployed/segmented primary mirror (4.5 meter fairing diameter) 20 kg/m2 areal density (PM 1000 kg mass) Such mirror technology had never been demonstrated - and did not exist

Double arch mirror study. Part 1: Preliminary engineering report

NASA Technical Reports Server (NTRS)

Vukobratovich, D.; Hillman, D.

1983-01-01

In the proposed design, the NASA AMES 20-in double arch mirror is supported by three clamp and flexure assemblies. The mirror clamp consists of a T-shaped Invar-36 member that goes into a similarly shaped socket in the back of the mirror. The mirror socket is made oversize and contacts the clamp only along the conical surface. The clamp is preloaded by a spring washer and pulls the mirror into contact with the flexure. The clamp is then inserted into the mirror socket through a cutout, is rotated 90 deg, and is then pinned in place. Loading conditions considered in socket design are discussed as well as stress in the socket and clamp. Flexure geometry and stress are examined as well as the effects of flexure error and of mirror cell error.

X-ray telescope mirrors made of slumped glass sheets

NASA Astrophysics Data System (ADS)

Winter, A.; Breunig, E.; Friedrich, P.; Proserpio, L.

2017-11-01

For several decades, the field of X-ray astronomy has been playing a major role in understanding the processes in our universe. From binary stars and black holes up to galaxy clusters and dark matter, high energetic events have been observed and analysed using powerful X-ray telescopes like e.g. Rosat, Chandra, and XMM-Newton [1,2,3], giving us detailed and unprecedented views of the high-energy universe. In November 2013, the theme of "The Hot and Energetic Universe" was rated as of highest importance for future exploration and in June 2014 the ATHENA Advanced Telescope for High Energy Astrophysics was selected by ESA for the second large science mission (L2) in the ESA Cosmic Vision program, with launch foreseen in 2028 [4]. By combining a large X-ray telescope with state-of-the-art scientific instruments, ATHENA will address key questions in astrophysics, including: How and why does ordinary matter assemble into the galaxies and galactic clusters that we see today? How do black holes grow and influence their surroundings? In order to answer these questions, ATHENA needs a powerful mirror system which exceed the capabilities of current missions, especially in terms of collecting area. However, current technologies have reached the mass limits of the launching rocket, creating the need for more light-weight mirror systems in order to enhance the effective area without increasing the telescope mass. Hence new mirror technologies are being developed which aim for low-weight systems with large collecting areas. Light material like glass can be used, which are shaped to form an X-ray reflecting system via the method of thermal glass slumping.

Fabrication Methods for Adaptive Deformable Mirrors

NASA Technical Reports Server (NTRS)

Toda, Risaku; White, Victor E.; Manohara, Harish; Patterson, Keith D.; Yamamoto, Namiko; Gdoutos, Eleftherios; Steeves, John B.; Daraio, Chiara; Pellegrino, Sergio

2013-01-01

Previously, it was difficult to fabricate deformable mirrors made by piezoelectric actuators. This is because numerous actuators need to be precisely assembled to control the surface shape of the mirror. Two approaches have been developed. Both approaches begin by depositing a stack of piezoelectric films and electrodes over a silicon wafer substrate. In the first approach, the silicon wafer is removed initially by plasmabased reactive ion etching (RIE), and non-plasma dry etching with xenon difluoride (XeF2). In the second approach, the actuator film stack is immersed in a liquid such as deionized water. The adhesion between the actuator film stack and the substrate is relatively weak. Simply by seeping liquid between the film and the substrate, the actuator film stack is gently released from the substrate. The deformable mirror contains multiple piezoelectric membrane layers as well as multiple electrode layers (some are patterned and some are unpatterned). At the piezolectric layer, polyvinylidene fluoride (PVDF), or its co-polymer, poly(vinylidene fluoride trifluoroethylene P(VDF-TrFE) is used. The surface of the mirror is coated with a reflective coating. The actuator film stack is fabricated on silicon, or silicon on insulator (SOI) substrate, by repeatedly spin-coating the PVDF or P(VDFTrFE) solution and patterned metal (electrode) deposition. In the first approach, the actuator film stack is prepared on SOI substrate. Then, the thick silicon (typically 500-micron thick and called handle silicon) of the SOI wafer is etched by a deep reactive ion etching process tool (SF6-based plasma etching). This deep RIE stops at the middle SiO2 layer. The middle SiO2 layer is etched by either HF-based wet etching or dry plasma etch. The thin silicon layer (generally called a device layer) of SOI is removed by XeF2 dry etch. This XeF2 etch is very gentle and extremely selective, so the released mirror membrane is not damaged. It is possible to replace SOI with silicon substrate, but this will require tighter DRIE process control as well as generally longer and less efficient XeF2 etch. In the second approach, the actuator film stack is first constructed on a silicon wafer. It helps to use a polyimide intermediate layer such as Kapton because the adhesion between the polyimide and silicon is generally weak. A mirror mount ring is attached by using adhesive. Then, the assembly is partially submerged in liquid water. The water tends to seep between the actuator film stack and silicon substrate. As a result, the actuator membrane can be gently released from the silicon substrate. The actuator membrane is very flat because it is fixed to the mirror mount prior to the release. Deformable mirrors require extremely good surface optical quality. In the technology described here, the deformable mirror is fabricated on pristine substrates such as prime-grade silicon wafers. The deformable mirror is released by selectively removing the substrate. Therefore, the released deformable mirror surface replicates the optical quality of the underlying pristine substrate.

The Breadboard model of the LISA telescope assembly

NASA Astrophysics Data System (ADS)

Lucarelli, S.; Scheulen, D.; Kemper, D.; Sippel, R.; Verlaan, A.; Hogenhuis, H.; Ende, D.

2017-11-01

The primary goal of the LISA mission is the detection of gravitational waves from astronomical sources in a frequency range of 10-4 to 1 Hz. This requires operational stabilities in the picometer range as well as highly predictable mechanical distortions upon cooling down, outgassing in space, and gravity release. In March 2011 ESA announced a new way forward for the Lclass candidate missions, including LISA. ESA and the scientific community are now studying options for European-only missions that offer a significant reduction of the costs, while maintaining their core science objectives. In this context LISA has become the New Gravitational wave Observatory (NGO). Despite this reformulation, the need for dimensional stability in the picometer range remains valid, and ESA have continued the corresponding LISA Technology Development Activities (TDA's) also in view of NGO. In such frame Astrium GmbH and xperion (Friedrichshafen, Germany) have designed and manufactured an ultra-stable CFRP breadboard of the LISA telescope in order to experimentally demonstrate that the structure and the M1 & M2 mirror mounts are fulfilling the LISA requirements in the mission operational thermal environment. Suitable techniques to mount the telescope mirrors and to support the M1 & M2 mirrors have been developed, with the aim of measuring a system CTE of less than 10-7 K-1 during cooling down to -80°C. Additionally to the stringent mass and stiffness specifications, the required offset design makes the control of relative tilts and lateral displacements between the M1 and M2 mirrors particularly demanding. The thermo-elastic performance of the telescope assembly is going to be experimentally verified by TNO (Delft, The Netherlands) starting from the second half of 2012. This paper addresses challenges faced in the design phase, shows the resulting hardware and present first outcomes of the test campaign performed at TNO.

The Breadboard Model of the LISA Telescope Assembly

NASA Astrophysics Data System (ADS)

Lucarelli, Stefano; Scheulen, Dietmar; Kemper, Daniel; Sippel, Rudolf; Ende, David

2012-07-01

The primary goal of the LISA mission is the detection of gravitational waves from astronomical sources in a frequency range of 10-4 to 1 Hz. This requires operational stabilities in the picometer range as well as highly predictable mechanical distortions upon cooling down, outgassing in space, and gravity release. In March 2011 ESA announced a new way forward for the L-class candidate missions, including LISA. ESA and the scientific community are now studying options for European-only missions that offer a significant reduction of the costs, while maintaining their core science objectives. In the context of this reformulation exercise LISA has become the New Gravitational wave Observatory (NGO) [1]. Despite this reformulation, the need for dimensional stability in the picometer range remains valid, and ESA have continued the corresponding LISA Technology Development Activities (TDA’s) also in view of NGO. In such frame Astrium GmbH and xperion (Immenstaad/Friedrichshafen, Germany) have designed and manufactured an ultra-stable CFRP breadboard of the LISA telescope in order to experimentally demonstrate that the structure and the M1 & M2 mirror mounts are fulfilling the LISA requirements in the mission operational thermal environment. Suitable techniques to mount the telescope mirrors and to support the M1 & M2 mirrors have been developed, with the aim of measuring a system CTE of less than 10-7 K-1 during cooling down to -80 °C. Additionally to the stringent mass and stiffness specifications, the required offset design makes the control of relative tilts and lateral displacements between the M1 and M2 mirrors particularly demanding. The thermo-elastic performance of the telescope assembly is going to be experimentally verified by TNO (Delft, The Netherlands) starting from the second half of 2012. This paper addresses challenges faced in the design phase, and shows the resulting hardware.

Infrared floodlight

DOEpatents

Levin, Robert E.; English, George J.

1986-08-05

An infrared floodlight assembly designed particularly for security purposes and including a heat-conducting housing, a lens secured to the housing to provide a closure therefor, and a floodlight located within (and surrounded by) the housing. The floodlight combines the use of a tungsten halogen light source and dichroic hot and cold mirrors for directing substantially only infrared radiation toward the assembly's forward lens. Visible radiation is absorbed by the housing's interior wall(s) and, optionally, by a filter located between the floodlight and lens. An optional means may be used within the floodlight to reflect all forward radiation back toward the paraboloidal hot mirror or, alternatively, to reflect only visible radiation in this direction. The dichroic hot and cold mirrors preferably each comprise a glass substrate having multiple layers of titanium dioxide and silicon dioxide thereon.

The design and assembly of aluminum mirrors of a three-mirror-anastigmat telescope

NASA Astrophysics Data System (ADS)

Chang, Shenq-Tsong; Lin, Yu-Chuan; Wu, Kun-Huan; Lien, Chun-Chieh; Huang, Ting-Ming; Tsay, Ho-Lin; Chan, Chia-Yen

2017-09-01

Better ground sampling distance (GSD) has been a trend for earth observation satellites. A long-focal-length telescope is required accordingly in systematic point of view. On the other hand, there is size constraint for such long-focal-length telescope especially in space projects. Three-mirror-anastigmat (TMA) was proven to have excellent features of correcting aberrations, wide spectral range and shorter physical requirement [1-3].

Preliminary Electrical Designs for CTEX and AFIT Satellite Ground Station

DTIC Science & Technology

2010-03-01

with additional IO High-Speed Piezo Tip/Tilt Platforms S-340 Platform Recommended Models Mirror Aluminum Aluminum S-340.Ax Invar Zerodur glass S-340...developed by RC Optics that uses internal steer- able mirrors that point the optics without slewing the entire instrument. The imaging system is composed of...Determination System Telescope Assembly CTEx Imaging System DCCU Camera Motor/Encoder Assemby FSM & Control Electronics Dwell Mirror w/ 2

Solar Thermal Propulsion for Microsatellite Manoeuvring

DTIC Science & Technology

2004-09-01

of 14-cm and 56-cm diameter solar concentrating mirrors has clearly validated initial optical ray trace modelling and suggests that there is...concentrating mirror’s focus, permitting multiple mirror inputs to heat a single receiver and allowing the receiver to be placed anywhere on the host...The STE is conceptually simple, relying on a mirror or lens assembly to collect and concentrate incident solar radiation. This energy is focused, by

Design of an adjustable bipod flexure for a large-aperture mirror of a space camera.

PubMed

Liu, Bei; Wang, Wei; Qu, Yan-Jun; Li, Xu-Peng; Wang, Xiao; Zhao, Hui

2018-05-20

An adjustable bipod flexure (ABF) technique for a large-aperture mirror of a space camera is presented. The proposed flexure mount can decrease the surface distortions caused by the machining error and the assembly error of the mirror assembly (MA) in a horizontal optical testing layout. Through the analysis of the compliance matrix of conventional bipod flexure, the positional relationship between the rotation center and the apex of the flexure is investigated. Then, the principle of the adjustable flexure, known as the trapezoidal switching principle, is proposed based on the analysis result. The structure and application of the flexure are also described. The optical performance of the mirror mounted by the adjustable flexures in different misalignments was performed using finite element methods. The result shows that the astigmatic aberration due to gravity is effectively reduced by adjusting the mount, and the root-mean-square value of the mirror can be minimized with the misalignment between the flexure pivot and the neutral plane minimized. New monolithic bipod flexures, based on the optimal regulating variable Δ u according to the measurement results, are manufactured to replace the ABFs to secure the mirror's safety against launch loads. Modal analysis verified the mechanical safety of the MA with respect to the new monolithic flexures.

Absolute Effective Area of the Chandra High-Resolution Mirror Assembly

NASA Technical Reports Server (NTRS)

Schwartz, D. A.; David, L. P.; Donnelly, R. H.; Edgar, R. J.; Gaetz, T. J.; Jerius, D.; Juda, M.; Kellogg, E. M.; McNamara, B. R.; Dewey, D.

2000-01-01

The Chandra X-ray Observatory was launched in July 1999, and is returning exquisite sub-arcsecond x-ray images of star groups, supernova remnants, galaxies, quasars, and clusters of galaxies. In addition to being the premier X-ray observatory in terms of angular and spectral resolution, Chandra is the best calibrated X-ray facility ever flown. We discuss here the calibration of the effective area of the High Resolution Mirror Assembly. Because we do not know the absolute X-ray flux density of any celestial source, this must be based primarily on ground measurements and on modeling. In particular, we must remove the calibrated modeled responses of the detectors and gratings to obtain the mirror area. For celestial sources which may be assumed to have smoothly varying spectra, such as the Crab Nebula, we may verify the continuity of the area calibration as a function of energy. This is of significance in energy regions such as the Ir M-edges, or near the critical grazing angle cutoff of the various mirror shells.

Tunable liquid optics: electrowetting-controlled liquid mirrors based on self-assembled Janus tiles.

PubMed

Bucaro, Michael A; Kolodner, Paul R; Taylor, J Ashley; Sidorenko, Alex; Aizenberg, Joanna; Krupenkin, Tom N

2009-04-09

In this paper, we describe a tunable, high-reflectivity optofluidic device based on self-assembly of anisotropically functionalized hexagonal micromirrors (Janus tiles) on the surface of an oil droplet to create a concave liquid mirror. The liquid mirror is deposited on a patterned transparent electrode that allows the focal length and axial position to be electrically controlled. The mirror is mechanically robust and retains its integrity even at high levels of vibrational excitation of the interface. The use of reflection instead of refraction overcomes the limited available refractive-index contrast between pairs of density-matched liquids, allowing stronger focusing than is possible for a liquid lens of the same geometry. This approach is compatible with optical instruments that could provide novel functionality-for example, a dynamic 3D projector, i.e., a light source which can scan an image onto a moving, nonplanar focal surface. Janus tiles with complex optical properties can be manufactured using our approach, thus potentially enabling a wide range of novel optical elements.

Tunable liquid optics: electrowetting-controlled liquid mirrors based on self-assembled Janus tiles

NASA Astrophysics Data System (ADS)

Krupenkin, Tom; Bucaro, Mike; Kolodner, Paul; Taylor, Ashley; Sidorenko, Alex; Aizenberg, Joanna

2009-03-01

In this work we describe a tunable, high-reflectivity optofluidic device based on self-assembly of anisotropically-functionalized hexagonal micromirrors (Janus tiles) on the surface of an oil droplet to create a concave liquid mirror. The liquid mirror is deposited on a patterned transparent electrode that allows the focal length and axial position to be electrically controlled. The mirror is mechanically robust and retains its integrity even at high levels of vibrational excitation of the interface. The use of reflection instead of refraction overcomes the limited available refractive-index contrast between pairs of density-matched liquids, allowing stronger focusing than is possible for a liquid lens of the same geometry. This approach is compatible with optical instruments that could provide novel functionality - for example, a dynamic 3D projector; i.e., a light source which can scan an image onto a moving, non-planar focal surface. Janus tiles with complex optical properties can be manufactured using our approach, thus potentially enabling a wide range of novel optical elements.

Method of forming structural heliostat

DOEpatents

Anderson, Alfred J.

1984-06-26

In forming a heliostat having a main support structure and pivoting and tilting motors and gears and a mirror module for reflecting solar energy onto a collector, the improvement characterized by a method of forming the mirror module in which the mirror is laid upon a solid rigid supporting bed in one or more sections, with or without focusing; a mirror backing sheet is applied by first applying respective thin layers of silicone grease and, thereafter, progressively rolling application to eliminate air bubbles; followed by affixing of a substrate assembly to the mirror backing sheet to form a mirror module that does not curve because of thermally induced stresses and differential thermal expansion or contraction effects. The silicone grease also serves to dampen fluttering of the mirror and protect the mirror backside against adverse effects of the weather. Also disclosed are specific details of preferred embodiments.

Spherical Primary Optical Telescope (SPOT): An Architecture Demonstration for Cost-effective Large Space Telescopes

NASA Technical Reports Server (NTRS)

Feinberg, Lee D.; Hagopian, John; Budinoff, Jason; Dean, Bruce; Howard, Joe

2004-01-01

This paper summarizes efforts underway at the Goddard Space Flight Center to demonstrate a new type of space telescope architecture that builds on the rigid segmented telescope heritage of the James Webb Space Telescope but that solves several key challenges for future space telescopes. The architecture is based on a cost-effective segmented spherical primary mirror combined with a unique wavefront sensing and control system that allows for continuous phasing of the primary mirror. The segmented spherical primary allows for cost-effective 3-meter class (e.g., Midex and Discovery) missions as well as enables 30-meter telescope solutions that can be manufactured in a reasonable amount of time and for a reasonable amount of money. The continuous wavefront sensing and control architecture enables missions in low-earth-orbit and missions that do not require expensive stable structures and thermal control systems. For the 30-meter class applications, the paper discusses considerations for assembling and testing the telescopes in space. The paper also summarizes the scientific and technological roadmap for the architecture and also gives an overview of technology development, design studies, and testbed activities underway to demonstrate its feasibility.

Research Technology

NASA Image and Video Library

1999-11-01

Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. This photograph shows a fully assembled solar thermal engine placed inside the vacuum chamber at the test facility prior to testing. The 20- by 24-ft heliostat mirror (not shown in this photograph) has a dual-axis control that keeps a reflection of the sunlight on the 18-ft diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move theNation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth orbit, rapid travel throughout the solar system, and exploration of interstellar space.

Spherical Primary Optical Telescope (SPOT): An Architecture Demonstration for Cost-effective Large Space Telescopes

NASA Technical Reports Server (NTRS)

Feinberg, Lee; Hagopian, John; Budinoff, Jason; Dean, Bruce; Howard, Joe

2005-01-01

This paper summarizes efforts underway at the Goddard Space Flight Center to demonstrate a new type of space telescope architecture that builds on the rigid, segmented telescope heritage of the James Webb Space Telescope but that solves several key challenges for future space telescopes. The architecture is based on a cost-effective segmented spherical primary mirror combined with a unique wavefront sensing and control system that allows for continuous phasing of the primary mirror. The segmented spherical primary allows for cost-effective 3-meter class (eg, Midex and Discovery) missions as well as enables 30-meter telescope solutions that can be manufactured in a reasonable amount of time and for a reasonable amount of money. The continuous wavefront sensing and control architecture enables missions in low-earth-orbit and missions that do not require expensive stable structures and thermal control systems. For the 30-meter class applications, the paper discusses considerations for assembling and testing the telescopes in space. The paper also summarizes the scientific and technological roadmap for the architecture and also gives an overview of technology development, design studies, and testbed activities underway to demonstrate it s feasibility.

Simon Newcomb, America’s First Great Astronomer

DTIC Science & Technology

2009-02-01

1874 and 1882 transits of Venus across the Sun. A heliostat tracked the Sun and reflected its light through a fixed telescope, where the image was...a new and unique camera consisting of a heliostat , long-focal-length telescope, and photographic plate assembly5 (see figures 2 and 3). While the...and relays or solenoids qualified as leading- Remote mirror Objective lenses Rotating mirrorFixed mirror Observer’s eyepiece Adjustable slit Heliostat

Large optics technology; Proceedings of the Meeting, San Diego, CA, August 19-21, 1985. Volume 571

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanger, G.M.

1986-01-01

The present conference on telescope primary mirror design and manufacturing technologies considers topics in mirror fabrication and testing, novel technology currently under development, recently instituted large optics development programs, and large mirror materials. Among the topics discussed are aspheric figure generation using feedback from an IR phase-shifting interferometer, thermal stability tests of CFRP sandwich panels for far-IR astronomy, Zerodur lightweight (large mirror) blanks, and the precision machining of grazing-incidence X-ray mirror substrates. Also treated are the rapid fabrication of large aspheric optics, steps toward 8-m honeycomb mirrors, a novel telescope design employing the refraction of prism rows, telescope technology formore » the Far-UV Spectroscopic Explorer, hot isostatic-pressed Be for large optics, and a concept for a moderate cost large deployable reflector.« less

Cryogenic optical testing results of JWST aspheric test plate lens

NASA Astrophysics Data System (ADS)

Smith, Koby Z.; Towell, Timothy C.

2011-09-01

The James Webb Space Telescope (JWST) Secondary Mirror Assembly (SMA) is a circular 740mm diameter beryllium convex hyperboloid that has a 23.5nm-RMS (λ/27 RMS) on-orbit surface figure error requirement. The radius of curvature of the SMA is 1778.913mm+/-0.45mm and has a conic constant of -1.6598+/-0.0005. The on-orbit operating temperature of the JWST SMA is 22.5K. Ball Aerospace & Technologies Corp. (BATC) is under contract to Northrop Grumman Aerospace Systems (NGAS) to fabricate, assemble, and test the JWST SMA to its on-orbit requirements including the optical testing of the SMA at its cryogenic operating temperature. BATC has fabricated and tested an Aspheric Test Plate Lens (ATPL) that is an 870mm diameter fused silica lens used as the Fizeau optical reference in the ambient and cryogenic optical testing of the JWST Secondary Mirror Assembly (SMA). As the optical reference for the SMA optical test, the concave optical surface of the ATPL is required to be verified at the same 20K temperature range required for the SMA. In order to meet this objective, a state-of-the-art helium cryogenic testing facility was developed to support the optical testing requirements of a number of the JWST optical testing needs, including the ATPL and SMA. With the implementation of this cryogenic testing facility, the ATPL was successfully cryogenically tested and performed to less than 10nm-RMS (λ/63 RMS) surface figure uncertainty levels for proper reference backout during the SMA optical testing program.

The center of curvature optical assembly for the JWST primary mirror cryogenic optical test: optical verification

NASA Astrophysics Data System (ADS)

Wells, Conrad; Olczak, Gene; Merle, Cormic; Dey, Tom; Waldman, Mark; Whitman, Tony; Wick, Eric; Peer, Aaron

2010-08-01

The James Webb Space Telescope (JWST) Optical Telescope Element (OTE) consists of a 6.6 m clear aperture, allreflective, three-mirror anastigmat. The 18-segment primary mirror (PM) presents unique and challenging assembly, integration, alignment and testing requirements. A full aperture center of curvature optical test is performed in cryogenic vacuum conditions at the integrated observatory level to verify PM performance requirements. The Center of Curvature Optical Assembly (CoCOA), designed and being built by ITT satisfies the requirements for this test. The CoCOA contains a multi wave interferometer, patented reflective null lens, actuation for alignment, full in situ calibration capability, coarse and fine alignment sensing systems, as well as a system for monitoring changes in the PM to CoCOA distance. Two wave front calibration tests are utilized to verify the low and Mid/High spatial frequencies, overcoming the limitations of the standard null/hologram configuration in its ability to resolve mid and high spatial frequencies. This paper will introduce the systems level architecture and optical test layout for the CoCOA.

Self-assembled hierarchical nanostructures for high-efficiency porous photonic crystals.

PubMed

Passoni, Luca; Criante, Luigino; Fumagalli, Francesco; Scotognella, Francesco; Lanzani, Guglielmo; Di Fonzo, Fabio

2014-12-23

The nanoscale modulation of material properties such as porosity and morphology is used in the natural world to mold the flow of light and to obtain structural colors. The ability to mimic these strategies while adding technological functionality has the potential to open up a broad array of applications. Porous photonic crystals are one such technological candidate, but have typically underachieved in terms of available materials, structural and optical quality, compatibility with different substrates (e.g., silicon, flexible organics), and scalability. We report here an alternative fabrication method based on the bottom-up self-assembly of elementary building blocks from the gas phase into high surface area photonic hierarchical nanostructures at room temperature. Periodic refractive index modulation is achieved by stacking layers with different nanoarchitectures. High-efficiency porous Bragg reflectors are successfully fabricated with sub-micrometer thick films on glass, silicon, and flexible substrates. High diffraction efficiency broadband mirrors (R≈1), opto-fluidic switches, and arrays of photonic crystal pixels with size<10 μm are demonstrated. Possible applications in filtering, sensing, electro-optical modulation, solar cells, and photocatalysis are envisioned.

Flight solar calibrations using the Mirror Attenuator Mosaic (MAM): Low scattering mirror

NASA Technical Reports Server (NTRS)

Lee, Robert B., III

1992-01-01

Measurements of solar radiances reflected from the mirror attenuator mosaic (MAM) were used to calibrate the shortwave portions of the Earth Radiation Budget Experiment (ERBE) thermistor bolometer scanning radiometers. The MAM is basically a low scattering mirror which has been used to attenuate and reflect solar radiation into the fields of view for the broadband shortwave (0.2 to 5 micrometers) and total (0.2 to 50.0+ micrometers) ERBE scanning radiometers. The MAM assembly consists of a tightly packed array of aluminum, 0.3175-cm diameter concave spherical mirrors and field of view limiting baffles. The spherical mirrors are masked by a copper plate, electro-plated with black chrome. Perforations (0.14 centimeter in diameter) in the copper plate serve as apertures for the mirrors. Black anodized aluminum baffles limit the MAM clear field of view to 7.1 degrees. The MAM assemblies are located on the Earth Radiation Budget Satellite (ERBS) and on the National Oceanic and Atmospheric Administration NOAA-9 and NOAA-10 spacecraft. The 1984-1985 ERBS and 1985-1986 NOAA-9 solar calibration datasets are presented. Analyses of the calibrations indicate that the MAM exhibited no detectable degradation in its reflectance properties and that the gains of the shortwave scanners did not change. The stability of the shortwave radiometers indicates that the transmission of the Suprasil W1 filters did not degrade detectably when exposed to Earth/atmosphere-reflected solar radiation.

Cable and Line Inspection Mechanism

NASA Technical Reports Server (NTRS)

Ross, Terence J. (Inventor)

2003-01-01

An automated cable and line inspection mechanism visually scans the entire surface of a cable as the mechanism travels along the cable=s length. The mechanism includes a drive system, a video camera, a mirror assembly for providing the camera with a 360 degree view of the cable, and a laser micrometer for measuring the cable=s diameter. The drive system includes an electric motor and a plurality of drive wheels and tension wheels for engaging the cable or line to be inspected, and driving the mechanism along the cable. The mirror assembly includes mirrors that are positioned to project multiple images of the cable on the camera lens, each of which is of a different portion of the cable. A data transceiver and a video transmitter are preferably employed for transmission of video images, data and commands between the mechanism and a remote control station.

Cable and line inspection mechanism

NASA Technical Reports Server (NTRS)

Ross, Terence J. (Inventor)

2003-01-01

An automated cable and line inspection mechanism visually scans the entire surface of a cable as the mechanism travels along the cable=s length. The mechanism includes a drive system, a video camera, a mirror assembly for providing the camera with a 360 degree view of the cable, and a laser micrometer for measuring the cable=s diameter. The drive system includes an electric motor and a plurality of drive wheels and tension wheels for engaging the cable or line to be inspected, and driving the mechanism along the cable. The mirror assembly includes mirrors that are positioned to project multiple images of the cable on the camera lens, each of which is of a different portion of the cable. A data transceiver and a video transmitter are preferably employed for transmission of video images, data and commands between the mechanism and a remote control station.

Electromagnetic DM technology meets future AO demands

NASA Astrophysics Data System (ADS)

Hamelinck, Roger; Rosielle, Nick; Steinbuch, Maarten; Doelman, Niek

New deformable mirror technology is developed by the Technische Universiteit Eindhoven, Delft University of Technology and TNO Science and Industry. Several prototype adaptive deformable mirrors are realized mirrors, up to 427 actuators and ∅150mm diameter, with characteristics suitable for future AO systems. The prototypes consist of a 100µm thick, continuous facesheet on which low voltage, electromagnetic, push-pull actuators impose out-of-plane displacements. The variable reluctance actuators with ±10µm stroke and nanometer resolution are located in a standard actuator module. Each module with 61 actuators connects to a single PCB with dedicated, 16 bit, PWM based, drivers. A LVDS multi-drop cable connects up to 32 actuator modules. With the actuator module, accompanying PCB and multi-drop system the deformable mirror technology is made modular in its mechanics and electronics. An Ethernet-LVDS bridge enables any commercial PC to control the mirror using the UDP standard. Latest results of the deformable mirror technology development are presented.

IR Imaging Study on Heater Performamnce of Outside Rearview Mirrors for Automobiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hsin; England, Todd W

Adhesive bonded electrical heaters have been used in outside rearview mirrors of automobiles in order to act as defrosters. Entrapment of air pockets between the heater and the mirror can affects the performance and structural integrity of the mirror assembly. Since painting over the mirror is not an option in the production environment, the biggest challenge for IR imaging is to minimize surface reflection. Looking through a smooth, highly reflective first-surface mirror and a 2 mm thick glass without picking up other heat sources in the room, such as people, electronics equipment and the camera itself, requires careful planning andmore » effective shielding. In this paper, we present our method of avoiding mirror reflection and IR images of the heated mirror in operation. Production heaters and heaters with artificial defect were studied. The IR imaging method has shown to be an effective tool for heater quality control and performance studies.« less

Status of Mirror Technology for the Next Generation Space Telescope

NASA Astrophysics Data System (ADS)

Jacobson, D. N.

2000-10-01

The NGST primary mirror is anticipated to be a segmented deployable optic with segment size being in the range of 1-3m depending on the details of the architecture. Over the past 4 years the NGST program has initiated and implemented an aggressive lightweight cryogenic mirror technology program. The program was designed to challenge and excite the optical community in reaching a new standard in production of lightweight optics. The goal was to develop optics at < 15 kg/m2, operational at ~ 40K and meeting the overall NGST observatory requirement for diffraction limited performance at 2 microns. In order to meet the NGST needs, technology efforts were initiated to investigate and develop mirrors in a variety of materials, which held promise for the program. The basic technology approaches have initially targeted the production of large mirrors in the 1.2-2.0m diameter range (or side-to-side distance in the case of hexagonal optics). Although this size may not be the final size of an NGST primary mirror segment, it was felt that a 1.2-2.0m optic would be of sufficient size to understand the mirror material and fabrication processes which drive the cost and schedule of mirror production. The ultimate goals of the technology program are both to demonstrate mirrors meeting the NGST performance requirements, and to establish cost and schedule credibility for producing and implementing the mirrors for the NGST flight system. Establishing cost and schedule credibility is essential to NGST which is a cost capped mission, with past program experience demonstrating that the optics will be a large portion of the total cost of the program. The first two years of the program were dedicated to understanding the various applicable materials, funding those materials to various levels of maturity and implementing the first large mirror procurement, the NGST Mirror System Demonstrator (NMSD), in order to establish a benchmark for the state-of-the-art in lightweight optics and to establish credibility that the goals of NGST could be achieved. The past two years of the program has seen major steps in the development of several mirror materials, which not only might have NGST applicability but could also support other programs for other customers. Additionally, a second large mirror procurement, the Advanced Mirror System Demonstrator (AMSD), has been implemented providing a focal point to complete the mirror technology development and lead ultimately to the production of mirrors that will fly on NEXUS (NGST flight experimentand) and NGST. This talk will focus on a status of the mirror technology developed over the past 4 years on the NGST program.

The pressure control technology of the active stressed lap

NASA Astrophysics Data System (ADS)

Li, Ying; Wang, Daxing

2010-10-01

The active stressed lap polishing technology is a kind of new polishing technology that can actively deform the lap surface to become an off-axis asphere according to different lap position on mirror surface and different angle of lap. The pressure of the lap on the mirror is an important factor affecting the grinding efficiency of the optics mirror. The active stressed lap technology using dynamic pressure control solution in the process of polishing astronomical Aspheric Mirror with faster asphericity will provide the advantage like high polishing speed and natural smooth, etc. This article puts emphases on the pressure control technology of the active stressed lap technology. It requires that the active stressed lap keeps symmetrical vertical compression on the mirrors in the process of grinding mirrors. With a background of an active stressed lap 450mm in diameter, this article gives an outline of the pressure control organization, analyzes the principle of pressure control and proposes the limitations of the present pressure control organization and the relevant solutions, designs a digital pressure controller with C32-bit RISC embedded and gives the relevant experimental test result finally.

Two-stage optics - High-acuity performance from low-acuity optical systems

NASA Technical Reports Server (NTRS)

Meinel, Aden B.; Meinel, Marjorie P.

1992-01-01

The concept of two-stage optics, developed under a program to enhance the performance, lower the cost, and increase the reliability of the 20-m Large Deployable Telescope, is examined. The concept permits the large primary mirror to remain as deployed or as space-assembled, with phasing and subsequent control of the system done by a small fully assembled optical active element placed at an exit pupil. The technique is being applied to correction of the fabrication/testing error in the Hubble Space Telescope primary mirror. The advantages offered by this concept for very large space telescopes are discussed.

SXI Prototype mirror mount

NASA Technical Reports Server (NTRS)

1995-01-01

This final report describes the work performed from June 1993 to January 1995. The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule.

Advanced Mirror & Modelling Technology Development

NASA Technical Reports Server (NTRS)

Effinger, Michael; Stahl, H. Philip; Abplanalp, Laura; Maffett, Steven; Egerman, Robert; Eng, Ron; Arnold, William; Mosier, Gary; Blaurock, Carl

2014-01-01

The 2020 Decadal technology survey is starting in 2018. Technology on the shelf at that time will help guide selection to future low risk and low cost missions. The Advanced Mirror Technology Development (AMTD) team has identified development priorities based on science goals and engineering requirements for Ultraviolet Optical near-Infrared (UVOIR) missions in order to contribute to the selection process. One key development identified was lightweight mirror fabrication and testing. A monolithic, stacked, deep core mirror was fused and replicated twice to achieve the desired radius of curvature. It was subsequently successfully polished and tested. A recently awarded second phase to the AMTD project will develop larger mirrors to demonstrate the lateral scaling of the deep core mirror technology. Another key development was rapid modeling for the mirror. One model focused on generating optical and structural model results in minutes instead of months. Many variables could be accounted for regarding the core, face plate and back structure details. A portion of a spacecraft model was also developed. The spacecraft model incorporated direct integration to transform optical path difference to Point Spread Function (PSF) and between PSF to modulation transfer function. The second phase to the project will take the results of the rapid mirror modeler and integrate them into the rapid spacecraft modeler.

Deformable mirrors development program at ESO

NASA Astrophysics Data System (ADS)

Stroebele, Stefan; Vernet, Elise; Brinkmann, Martin; Jakob, Gerd; Lilley, Paul; Casali, Mark; Madec, Pierre-Yves; Kasper, Markus

2016-07-01

Over the last decade, adaptive optics has become essential in different fields of research including medicine and industrial applications. With this new need, the market of deformable mirrors has expanded a lot allowing new technologies and actuation principles to be developed. Several E-ELT instruments have identified the need for post focal deformable mirrors but with the increasing size of the telescopes the requirements on the deformable mirrors become more demanding. A simple scaling up of existing technologies from few hundred actuators to thousands of actuators will not be sufficient to satisfy the future needs of ESO. To bridge the gap between available deformable mirrors and the future needs for the E-ELT, ESO started a development program for deformable mirror technologies. The requirements and the path to get the deformable mirrors for post focal adaptive optics systems for the E-ELT is presented.

New Method for Characterizing the State of Optical and Opto-Mechanical Systems

NASA Technical Reports Server (NTRS)

Keski-Kuha, Ritva; Saif, Babak; Feinberg, Lee; Chaney, David; Bluth, Marcel; Greenfield, Perry; Hack, Warren; Smith, Scott; Sanders, James

2014-01-01

James Webb Space Telescope Optical Telescope Element (OTE) is a three mirror anastigmat consisting of a 6.5 m primary mirror (PM), secondary mirror (SM) and a tertiary mirror. The primary mirror is made out of 18 segments. The telescope and instruments will be assembled at Goddard Space Flight Center (GSFC) to make it the Optical Telescope Element-Integrated Science Instrument Module (OTIS). The OTIS will go through environmental testing at GSFC before being transported to Johnson Space Center for testing at cryogenic temperature. The objective of the primary mirror Center of Curvature test (CoC) is to characterize the PM before and after the environmental testing for workmanship. This paper discusses the CoC test including both a surface figure test and a new method for characterizing the state of the primary mirror using high speed dynamics interferometry.

Control-structure-thermal interactions in analysis of lunar telescopes

NASA Technical Reports Server (NTRS)

Thompson, Roger C.

1992-01-01

The lunar telescope project was an excellent model for the CSTI study because a telescope is a very sensitive instrument, and thermal expansion or mechanical vibration of the mirror assemblies will rapidly degrade the resolution of the device. Consequently, the interactions are strongly coupled. The lunar surface experiences very large temperature variations that range from approximately -180 C to over 100 C. Although the optical assemblies of the telescopes will be well insulated, the temperature of the mirrors will inevitably fluctuate in a similar cycle, but of much smaller magnitude. In order to obtain images of high quality and clarity, allowable thermal deformations of any point on a mirror must be less than 1 micron. Initial estimates indicate that this corresponds to a temperature variation of much less than 1 deg through the thickness of the mirror. Therefore, a lunar telescope design will most probably include active thermal control, a means of controlling the shape of the mirrors, or a combination of both systems. Historically, the design of a complex vehicle was primarily a sequential process in which the basic structure was defined without concurrent detailed analyses or other subsystems. The basic configuration was then passed to the different teams responsible for each subsystem, and their task was to produce a workable solution without requiring major alterations to any principal components or subsystems. Consequently, the final design of the vehicle was not always the most efficient, owing to the fact that each subsystem design was partially constrained by the previous work. This procedure was necessary at the time because the analysis process was extremely time-consuming and had to be started over with each significant alteration of the vehicle. With recent advances in the power and capacity of small computers, and the parallel development of powerful software in structural, thermal, and control system analysis, it is now possible to produce very detailed analyses of intermediate designs in a much shorter period of time. The subsystems can thus be designed concurrently, and alterations in the overall design can be quickly adopted into each analysis; the design becomes an iterative process in which it is much easier to experiment with new ideas, configurations, and components. Concurrent engineering has the potential to produce efficient, highly capable designs because the effect of one subystem on another can be assessed in much more detail at a very early point in the program. The research program consisted of several tasks: scale a prototype telescope assembly to a 1 m aperture, develop a model of the telescope assembly by using finite element (FEM) codes that are available on site, determine structural deflections of the mirror surfaces due to the temperature variations, develop a prototype control system to maintain the proper shape of the optical elements, and most important of all, demonstrate the concurrent engineering approach with this example. In addition, the software used for the finite element models and thermal analysis was relatively new within the Program Development Office and had yet to be applied to systems this large or complex; understanding the software and modifying it for use with this project was also required. The I-DEAS software by Structural Dynamics Research Corporation (SDRC) was used to build the finite element models, and TMG developed by Maya Heat Transfer Technologies, Ltd. (which runs as an I-DEAS module) was used for the thermal model calculations. All control system development was accomplished with MATRIX(sub X) by Integrated Systems, Inc.

Leon Van Speybroeck Wins Astrophysics Bruno Rossi Prize

NASA Technical Reports Server (NTRS)

2002-01-01

Leon Van Speybroeck of the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts was awarded the 2002 Bruno Rossi Prize of the High-Energy Astrophysics Division of the American Astronomy Society. The Rossi Prize is an arnual recognition of significant contributions in high-energy astrophysics in honor of the Massachusetts Institute of Technology's late Professor Bruno Rossi, an authority on cosmic ray physics and a pioneer in the field of x-ray astronomy. Van Speybroeck, who led the effort to design and make the x-ray mirrors for NASA's premier Chandra X-Ray Observatory, was recognized for a career of stellar achievements in designing precision x-ray optics. As Telescope Scientist for Chandra, he has worked for more than 20 years with a team that includes scientists and engineers from the Harvard-Smithsonian, NASA's Marshall Space Flight Center, TRW, Inc., Huhes-Danbury (now B.F. Goodrich Aerospace), Optical Coating Laboratories, Inc., and Eastman-Kodak on all aspects of the x-ray mirror assembly that is the heart of the observatory.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2002-01-23

Leon Van Speybroeck of the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts was awarded the 2002 Bruno Rossi Prize of the High-Energy Astrophysics Division of the American Astronomy Society. The Rossi Prize is an arnual recognition of significant contributions in high-energy astrophysics in honor of the Massachusetts Institute of Technology's late Professor Bruno Rossi, an authority on cosmic ray physics and a pioneer in the field of x-ray astronomy. Van Speybroeck, who led the effort to design and make the x-ray mirrors for NASA's premier Chandra X-Ray Observatory, was recognized for a career of stellar achievements in designing precision x-ray optics. As Telescope Scientist for Chandra, he has worked for more than 20 years with a team that includes scientists and engineers from the Harvard-Smithsonian, NASA's Marshall Space Flight Center, TRW, Inc., Huhes-Danbury (now B.F. Goodrich Aerospace), Optical Coating Laboratories, Inc., and Eastman-Kodak on all aspects of the x-ray mirror assembly that is the heart of the observatory.

Statistical analysis of the surface figure of the James Webb Space Telescope

NASA Astrophysics Data System (ADS)

Lightsey, Paul A.; Chaney, David; Gallagher, Benjamin B.; Brown, Bob J.; Smith, Koby; Schwenker, John

2012-09-01

The performance of an optical system is best characterized by either the point spread function (PSF) or the optical transfer function (OTF). However, for system budgeting purposes, it is convenient to use a single scalar metric, or a combination of a few scalar metrics to track performance. For the James Webb Space Telescope, the Observatory level requirements were expressed in metrics of Strehl Ratio, and Encircled Energy. These in turn were converted to the metrics of total rms WFE and rms WFE within spatial frequency domains. The 18 individual mirror segments for the primary mirror segment assemblies (PMSA), the secondary mirror (SM), tertiary mirror (TM), and Fine Steering Mirror have all been fabricated. They are polished beryllium mirrors with a protected gold reflective coating. The statistical analysis of the resulting Surface Figure Error of these mirrors has been analyzed. The average spatial frequency distribution and the mirror-to-mirror consistency of the spatial frequency distribution are reported. The results provide insight to system budgeting processes for similar optical systems.

Large aperture telescope technology: a design for an active lightweight multi-segmented fold-out space mirror

NASA Astrophysics Data System (ADS)

Thompson, S. J.; Doel, A. P.; Whalley, M.; Edeson, R.; Edeson, R.; Tosh, I.; Poyntz-Wright, O.; Atad-Ettedgui, E.; Montgomery, D.; Nawasra, J.

2017-11-01

Large aperture telescope technology (LATT) is a design study for a differential lidar (DIAL) system; the main investigation being into suitable methods, technologies and materials for a 4-metre diameter active mirror that can be stowed to fit into a typical launch vehicle (e.g. ROKOT launcher with 2.1-metre diameter cargo) and can self-deploy - in terms of both leaving the space vehicle and that the mirrors unfold and self-align to the correct optical form within the tolerances specified. The primary mirror requirements are: main wavelength of 935.5 nm, RMS corrected wavefront error of λ/6, optical surface roughness better than 5 nm, areal density of less than 16 kg/m2 and 1-2 mirror shape corrections per orbit. The primary mirror consists of 7 segments - a central hexagonal mirror and 6 square mirror petals which unfold to form the 4-meter diameter aperture. The focus of the UK LATT consortium for this European Space Agency (ESA) funded project is on using lightweighted aluminium or carbon-fibre-composite materials for the mirror substrate in preference to more traditional materials such as glass and ceramics; these materials have a high strength and stiffness to weight ratio, significantly reducing risk of damage due to launch forces and subsequent deployment in orbit. We present an overview of the design, which includes suitable actuators for wavefront correction, petal deployment mechanisms and lightweight mirror technologies. Preliminary testing results from manufactured lightweight mirror samples will also be summarised.

Development of replicated optics for AXAF-1 XDA testing

NASA Technical Reports Server (NTRS)

Engelhaupt, Darell; Wilson, Michele; Martin, Greg

1995-01-01

Advanced optical systems for applications such as grazing incidence Wolter I x-ray mirror assemblies require extraordinary mirror surfaces in terms of fine finish and surface figure. The impeccable mirror surface is on the inside of the rotational mirror form. One practical method of producing devices with these requirements is to first fabricate an exterior surface for the optical device then replicate that surface to have the inverse component with lightweight characteristics. The replicated optic is not better than the master or mandrel from which it is made. This task identifies methods and materials for forming these extremely low roughness optical components. The objectives of this contract were to (1) prepare replication samples of electroless nickel coated aluminum, and determine process requirements for plating XDA test optic; (2) prepare and assemble plating equipment required to process a demonstration optic; (3) characterize mandrels, replicas and test samples for residual stress, surface contamination and surface roughness and figure using equipment at MSFC and; (4) provide technical expertise in establishing the processes, procedures, supplies and equipment needed to process the XDA test optics.

EAGLE: relay mirror technology development

NASA Astrophysics Data System (ADS)

Hartman, Mary; Restaino, Sergio R.; Baker, Jeffrey T.; Payne, Don M.; Bukley, Jerry W.

2002-06-01

EAGLE (Evolutionary Air & Space Global Laser Engagement) is the proposed high power weapon system with a high power laser source, a relay mirror constellation, and the necessary ground and communications links. The relay mirror itself will be a satellite composed of two optically-coupled telescopes/mirrors used to redirect laser energy from ground, air, or space based laser sources to distant points on the earth or space. The receiver telescope captures the incoming energy, relays it through an optical system that cleans up the beam, then a separate transmitter telescope/mirror redirects the laser energy at the desired target. Not only is it a key component in extending the range of DoD's current laser weapon systems, it also enables ancillary missions. Furthermore, if the vacuum of space is utilized, then the atmospheric effects on the laser beam propagation will be greatly attenuated. Finally, several critical technologies are being developed to make the EAGLE/Relay Mirror concept a reality, and the Relay Mirror Technology Development Program was set up to address them. This paper will discuss each critical technology, the current state of the work, and the future implications of this program.

Conceptual design and structural analysis for an 8.4-m telescope

NASA Astrophysics Data System (ADS)

Mendoza, Manuel; Farah, Alejandro; Ruiz Schneider, Elfego

2004-09-01

This paper describes the conceptual design of the optics support structures of a telescope with a primary mirror of 8.4 m, the same size as a Large Binocular Telescope (LBT) primary mirror. The design goal is to achieve a structure for supporting the primary and secondary mirrors and keeping them joined as rigid as possible. With this purpose an optimization with several models was done. This iterative design process includes: specifications development, concepts generation and evaluation. Process included Finite Element Analysis (FEA) as well as other analytical calculations. Quality Function Deployment (QFD) matrix was used to obtain telescope tube and spider specifications. Eight spiders and eleven tubes geometric concepts were proposed. They were compared in decision matrixes using performance indicators and parameters. Tubes and spiders went under an iterative optimization process. The best tubes and spiders concepts were assembled together. All assemblies were compared and ranked according to their performance.

AXAF-1 High Resolution Assembly Image Model and Comparison with X-Ray Ground Test Image

NASA Technical Reports Server (NTRS)

Zissa, David E.

1999-01-01

The x-ray ground test of the AXAF-I High Resolution Mirror Assembly was completed in 1997 at the X-ray Calibration Facility at Marshall Space Flight Center. Mirror surface measurements by HDOS, alignment results from Kodak, and predicted gravity distortion in the horizontal test configuration are being used to model the x-ray test image. The Marshall Space Flight Center (MSFC) image modeling serves as a cross check with Smithsonian Astrophysical observatory modeling. The MSFC image prediction software has evolved from the MSFC model of the x-ray test of the largest AXAF-I mirror pair in 1991. The MSFC image modeling software development is being assisted by the University of Alabama in Huntsville. The modeling process, modeling software, and image prediction will be discussed. The image prediction will be compared with the x-ray test results.

Semikinematic mount for spatially constrained high aspect ratio spacecraft fold mirrors

NASA Astrophysics Data System (ADS)

Sahu, Rupali; Arora, Hemant; Munjal, Bhawdeep Singh

2017-12-01

An attempt has been made to propose a passive flexure-based semikinematic optimized mounting design for mirror fixing devices (MFDs) to mount spacecraft mirrors made of brittle materials, especially for high aspect ratio mirrors with low available space for mounting in satellites. The traditionally used tangent cantilever spiders occupy a lot of space and are suitable only for small mirrors. Similarly, the efficiency of flexural bipods is lost if not placed 120 deg apart, which is not possible in high aspect ratio mirrors. Two mounting configurations, one with collinear MFDs and the other with staggered MFDs, have been studied. An optimization problem is set up with dimensions of the proposed design as design variables and constraints imposed on structural performance of the mirror assembly. Investigations indicate that both configurations have potential applications in spacecrafts as they have provided feasible results and have satisfactory optical performance as well.

Single Crystal DMs for Space-Based Observatories

NASA Astrophysics Data System (ADS)

Bierden, Paul

We propose to demonstrate the feasibility of a new manufacturing process for large aperture, high-actuator count microelectromechanical deformable mirrors (MEMS-DMs). These DMs are designed to fill a critical technology gap in NASA s plan for high- contrast space-based exoplanet observatories. We will manufacture a prototype DM with a continuous mirror facesheet, having an active aperture of 50mm diameter, supported by 2040 electrostatic actuators (50 across the diameter of the active aperture), spaced at a pitch of 1mm. The DM will be manufactured using silicon microfabrication tools. The strategic motivation for the proposed project is to advance MEMS DMs as an enabling technology in NASA s rapidly emerging program for extrasolar planet exploration. That goal is supported by an Astro2010 white paper on Technologies for Direct Optical Imaging of Exoplanets, which concluded that DMs are a critical component for all proposed internal coronagraph instrument concepts. That white paper pointed to great strides made by DM developers in the past decade, and acknowledged the components made by Boston Micromachines Corporation to be the most notable MEMS-based technology option. The principal manufacturing innovation in this project will be assembly of the DM through fusion bonding of three separate single crystal silicon wafers comprising the device s substrate, actuator array, and facesheet. The most significant challenge of this project will be to develop processes that allow reliable fusion bonds between multiple compliant silicon layers while yielding an optically flat surface and a robust electromechanical system. The compliance of the DM, which is required for its electromechanical function, will make it challenging to achieve the intimate, planar contact that is generally needed for success in fusion bonding. The manufacturing approach will use photolithography and reactive ion etching to pattern structural layers. Three wafer-scale devices will be patterned and etched independently: one for the substrate and fixed electrode layer, one for the actuator layer, and one for the mirror layer. Subsequently, each of these wafers will be bonded through a thermal fusion process to the others. In an innovative new processing technique, we will employ sacrificial oxide pillars to add temporary support to the otherwise compliant device structures. These pillars will be dissolved after assembly. The result will be a stress-free, single crystal silicon device with broadly expanded design space for geometric parameters such as actuator pitch, mirror diameter, array size, and actuator gap. Consequently, this approach will allow us to make devices with characteristics that are needed for some important NASA applications in space-based coronography, especially where larger array sizes, greater actuator pitch, and better optical surface quality are needed. The significance of this work is that it will provide a technology platform that meets or exceeds the superb optical performance that has been demonstrated in conventional pizezoelectrically actuated DMs, while retaining the advantages in cost, repeatability, and thermal insensitivity that have been demonstrated in the newer generation of MEMS electrostatically actuated DMs. The shift to bonded single-crystal structures will eliminate the single biggest drawback in previously reported NASA-fielded MEMS DM technology: device susceptibility to stress-induced scalloping and print through artifacts resulting from polycrystalline thin film surface micromachining. With single crystal structures bonded at atomic scales, uncorrected surface topography can be controlled to subnanometer levels, enabling the advancement of NASA s next-generation space-based coronagraphs.

Design and development of thin quartz glass WFXT polynomial mirror shells by direct polishing

NASA Astrophysics Data System (ADS)

Proserpio, L.; Campana, S.; Citterio, O.; Civitani, M.; Combrinck, H.; Conconi, P.; Cotroneo, V.; Freeman, R.; Langstrof, P.; Mattaini, E.; Morton, R.; Oberle, B.; Pareschi, G.; Parodi, G.; Pels, C.; Schenk, C.; Stock, R.; Tagliaferri, G.

2010-07-01

The Wide Field X-ray Telescope (WFXT) is a medium class mission for X-ray surveys of the sky with an unprecedented area and sensitivity. In order to meet the effective area requirement, the design of the optical system is based on very thin mirror shells, with thicknesses in the 1-2 mm range. In order to get the desired angular resolution (10 arcsec requirement, 5 arcsec goal) across the entire 1x1 degree FOV (Field Of View), the design of the optical system is based on nested modified grazing incidence Wolter-I mirrors realized with polynomial profiles, focal plane curvature and plate scale corrections. This design guarantees an increased angular resolution at large off-axis angle with respect to the normally used Wolter I configuration, making WFXT ideal for survey purposes. The WFXT X-ray Telescope Assembly is composed by three identical mirror modules of 78 nested shells each, with diameter up to 1.1 m. The epoxy replication process with SiC shells has already been proved to be a valuable technology to meet the angular resolution requirement of 10 arcsec. To further mature the telescope manufacturing technology and to achieve the goal of 5 arcsec, a deterministic direct polishing method is under investigation. The direct polishing method has already been used for past missions (as Einstein, Rosat, Chandra): the technological challenge now is to apply it for almost ten times thinner shells. Under investigation is quartz glass (fused silica), a well-known material with good thermo-mechanical and polishability characteristics that could meet our goal in terms of mass and stiffness, with significant cost and time saving with respect to SiC. Our approach is based on two main steps: first quartz glass tubes available on the market are grinded to conical profiles, and second the obtained shells are polished to the required polynomial profiles by CNC (Computer Numerical Control) polishing machine. In this paper, the first results of the direct grinding and polishing of prototypes shells made by quartz glass with low thickness, representative of the WFXT optical design, are presented.

Last results of technological developments for ultra-lightweight, large aperture, deployable mirror for space telescopes

NASA Astrophysics Data System (ADS)

Gambicorti, Lisa; D'Amato, Francesco; Vettore, Christian; Duò, Fabrizio; Guercia, Alessio; Patauner, Christian; Biasi, Roberto; Lisi, Franco; Riccardi, Armando; Gallieni, Daniele; Lazzarini, Paolo; Tintori, Matteo; Zuccaro Marchi, Alessandro; Pereira do Carmo, Joao

2017-11-01

The aim of this work is to describe the latest results of new technological concepts for Large Aperture Telescopes Technology (LATT) using thin deployable lightweight active mirrors. This technology is developed under the European Space Agency (ESA) Technology Research Program and can be exploited in all the applications based on the use of primary mirrors of space telescopes with large aperture, segmented lightweight telescopes with wide Field of View (FOV) and low f/#, and LIDAR telescopes. The reference mission application is a potential future ESA mission, related to a space borne DIAL (Differential Absorption Lidar) instrument operating around 935.5 nm with the goal to measure water vapor profiles in atmosphere. An Optical BreadBoard (OBB) for LATT has been designed for investigating and testing two critical aspects of the technology: 1) control accuracy in the mirror surface shaping. 2) mirror survivability to launch. The aim is to evaluate the effective performances of the long stroke smart-actuators used for the mirror control and to demonstrate the effectiveness and the reliability of the electrostatic locking (EL) system to restraint the thin shell on the mirror backup structure during launch. The paper presents a comprehensive vision of the breadboard focusing on how the requirements have driven the design of the whole system and of the various subsystems. The manufacturing process of the thin shell is also presented.

Nonimaging polygonal mirrors achieving uniform irradiance distributions on concentrating photovoltaic cells.

PubMed

Schmitz, Max; Dähler, Fabian; Elvinger, François; Pedretti, Andrea; Steinfeld, Aldo

2017-04-10

We introduce a design methodology for nonimaging, single-reflection mirrors with polygonal inlet apertures that generate a uniform irradiance distribution on a polygonal outlet aperture, enabling a multitude of applications within the domain of concentrated photovoltaics. Notably, we present single-mirror concentrators of square and hexagonal perimeter that achieve very high irradiance uniformity on a square receiver at concentrations ranging from 100 to 1000 suns. These optical designs can be assembled in compound concentrators with maximized active area fraction by leveraging tessellation. More advanced multi-mirror concentrators, where each mirror individually illuminates the whole area of the receiver, allow for improved performance while permitting greater flexibility for the concentrator shape and robustness against partial shading of the inlet aperture.

Performance of the Primary Mirror Center-of-Curvature Optical Metrology System during Cryogenic Testing of the JWST Pathfinder Telescope

NASA Technical Reports Server (NTRS)

Hadaway, James B.; Wells, Conrad; Olczak, Gene; Waldman, Mark; Whitman, Tony; Cosentino, Joseph; Connolly, Mark; Chaney, David; Telfer, Randal

2016-01-01

The JWST primary mirror consists of 18 1.5 m hexagonal segments, each with 6-DoF and RoC adjustment. The telescope will be tested at its cryogenic operating temperature at Johnson Space Center. The testing will include center-of-curvature measurements of the PM, using the Center-of-Curvature Optical Assembly (COCOA) and the Absolute Distance Meter Assembly (ADMA). The performance of these metrology systems, including hardware, software, procedures, was assessed during two cryogenic tests at JSC, using the JWST Pathfinder telescope. This paper describes the test setup, the testing performed, and the resulting metrology system performance.

Development of advanced micromirror arrays by flip-chip assembly

NASA Astrophysics Data System (ADS)

Michalicek, M. Adrian; Bright, Victor M.

2001-10-01

This paper presents the design, commercial prefabrication, modeling and testing of advanced micromirror arrays fabricated using a novel, simple and inexpensive flip-chip assembly technique. Several polar piston arrays and rectangular cantilever arrays were fabricated using flip-chip assembly by which the upper layers of the array are fabricated on a separate chip and then transferred to a receiving module containing the lower layers. Typical polar piston arrays boast 98.3% active surface area, highly planarized surfaces, low address potentials compatible with CMOS electronics, highly standardized actuation between devices, and complex segmentation of mirror surfaces which allows for custom aberration configurations. Typical cantilever arrays boast large angles of rotation as well as an average surface planarity of only 1.779 nm of RMS roughness across 100 +m mirrors. Continuous torsion devices offer stable operation through as much as six degrees of rotation while binary operation devices offer stable activated positions with as much as 20 degrees of rotation. All arrays have desirable features of costly fabrication services like five structural layers and planarized mirror surfaces, but are prefabricated in the less costly MUMPs process. Models are developed for all devices and used to compare empirical data.

Fabrication of First 4-m Coils for the LARP MQXFA Quadrupole and Assembly in Mirror Structure

DOE PAGES

Holik, Eddie Frank; Ambrosio, Giorgio; Anerella, Michael; ...

2017-01-23

The US LHC Accelerator Research Program is constructing prototype interaction region quadrupoles as part of the US in-kind contribution to the Hi-Lumi LHC project. The low-beta MQXFA Q1/Q3 coils have a 4-m length and a 150 mm bore. The design is first validated on short, one meter models (MQXFS) developed as part of the longstanding Nb3Sn quadrupole R&D by LARP in collaboration with CERN. In parallel, facilities and tooling are being developed and refined at BNL, LBNL, and FNAL to enable long coil production, assembly, and cold testing. Long length scale-up is based on the experience from the LARP 90more » mm aperture (TQ-LQ) and 120 mm aperture (HQ and Long HQ) programs. A 4-m long MQXF practice coil was fabricated, water jet cut and analyzed to verify procedures, parts, and tooling. In parallel, the first complete prototype coil (QXFP01a) was fabricated and assembled in a long magnetic mirror, MQXFPM1, to provide early feedback on coil design and fabrication following the successful experience of previous LARP mirror tests.« less

STS-5 Columbia, OV-102, middeck documentation

NASA Technical Reports Server (NTRS)

1982-01-01

Items stowed temporarily on forward middeck lockers include (left to right) field sequential (FS) crew cabin camera, procedural notebook, communications kit assembly (assy) headset (HDST) interface unit (HIU), personal hygiene kit, personal hygiene mirror assy, meal tray assemblies, towels, and Vestibular Study Experiment headset and antenna.

Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly

NASA Technical Reports Server (NTRS)

Merle, Cormic; Wick, Eric; Hayden, Joseph

2011-01-01

This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics to make a differential distance measurement between a ring mirror on the reflective null assembly and individual PM segments. The ADM is located inside the same Pressure-Tight Enclosure (PTE) that houses the test interferometer. The PTE maintains the ADM and interferometer at ambient temperature and pressure so that they are not directly exposed to the telescope s harsh cryogenic and vacuum environment. This system takes advantage of the existing achromatic objective and reflective null assembly used by the test interferometer to direct four ADM beamlets to four PM segments through an optical path that is coincident with the interferometer beam. A mask, positioned on a linear slide, contains an array of 1.25 mm diameter circular subapertures that map to each of the 18 PM segments as well as six positions around the ring mirror. A down-collimated 4 mm ADM beam simultaneously covers 4 adjacent PM segment beamlets and one ring mirror beamlet. The radius, or spacing, of all 18 segments can be measured with the addition of two orthogonally-oriented scanning pentaprisms used to steer the ADM beam to any one of six different sub-aperture configurations at the plane of the ring mirror. The interferometer beam, at a wavelength of 687 nm, and the ADM beamlets, at a wavelength of 780 nm, pass through the objective and null so that the rays are normally incident on the parabolic PM surface. After reflecting off the PM, both the ADM and interferometer beams return to their respective instruments on nearly the same path. A fifth beamlet, acting as a differential reference, reflects off a ring mirror attached to the objective and null and returns to the ADM. The spacings between the ring mirror, objective, and null are known through manufacturing tolerances as well as through an in situ null wavefront alignment of the interferometer test beam with a reflective hologram located near the caustic of the null. Since total path length between the ring mirror and PM segments is highly deterministic, any ADM-measured departures from the predicted path length can be attributed to either spacing error or radius error in the PM. It is estimated that the path length measurement between the ring mirror and a PM segment is accurate to better than 100 m. The unique features of this invention include the differential distance measuring capability and its integration into an existing cryogenic and vacuum compatible interferometric optical test.

Wide scanning spherical antenna

NASA Technical Reports Server (NTRS)

Shen, Bing (Inventor); Stutzman, Warren L. (Inventor)

1995-01-01

A novel method for calculating the surface shapes for subreflectors in a suboptic assembly of a tri-reflector spherical antenna system is introduced, modeled from a generalization of Galindo-Israel's method of solving partial differential equations to correct for spherical aberration and provide uniform feed to aperture mapping. In a first embodiment, the suboptic assembly moves as a single unit to achieve scan while the main reflector remains stationary. A feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan thereby eliminating the need to oversize the main spherical reflector. In an alternate embodiment, both the main spherical reflector and the suboptic assembly are fixed. A flat mirror is used to create a virtual image of the suboptic assembly. Scan is achieved by rotating the mirror about the spherical center of the main reflector. The feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan.

Replicated Composite Optics Development

NASA Technical Reports Server (NTRS)

Engelhaupt, Darell

1997-01-01

Advanced optical systems for applications such as grazing incidence Wolter I x-ray mirror assemblies require extraordinary mirror surfaces in ten-ns of fine surface finish and figure. The impeccable mirror surface is on the inside of the rotational mirror form. One practical method of producing devices with these requirements is to first fabricate an exterior surface for the optical device then replicate that surface to have the inverse component with lightweight characteristics. The replicate optic is not better than the master or mandrel from which it is made. This task is a continuance of previous studies to identify methods and materials for forming these extremely low roughness optical components.

Cryogenic optics for space application

NASA Astrophysics Data System (ADS)

Fappani, Denis; Robert, Patrick

2017-11-01

For space born Astronomy as well as Earth Observation from space, more and more focal plane instruments are operating in the near or mid infrared and require therefore optics operating at cryogenic temperature (down to liquid nitrogen temperature or less). Through several examples of typical past or on-going realizations for different projects requiring such cryogenics optics (e.g. MTG=Meteosat Third Generation program for ESA), the presentation will point out the main technical issues and corresponding solutions for design, manufacturing and testing of necessary lens assemblies, mirrors and relevant optical coatings. A brief review of the corresponding existing "state of the art" for these technologies in Thales Seso will conclude the presentation.

Poco Graphite Mirror Metrology Report

NASA Technical Reports Server (NTRS)

Kester, Thomas J.

2005-01-01

Recently a lightweight mirror technology was tested at Marshall Space Flight Center's Space Optic Manufacturing Technology Center (MSFC, SOMTC). The mirror is a Poco Graphite CVD Si clad SiC substrate. It was tested for cryogenic (cryo) survivability to 20deg Kelvin in SOMTC's X-ray Calibration and Cryogenic Test Facility. The surface figure of the mirror was measured before and after cry0 cycling. The test technique and results are discussed.

The hard x-ray imager onboard IXO

NASA Astrophysics Data System (ADS)

Nakazawa, Kazuhiro; Takahashi, Tadayuki; Limousin, Olivier; Kokubun, Motohide; Watanabe, Shin; Laurent, Philippe; Arnaud, Monique; Tajima, Hiroyasu

2010-07-01

The Hard X-ray Imager (HXI) is one of the instruments onboard International X-ray Observatory (IXO), to be launched into orbit in 2020s. It covers the energy band of 10-40 keV, providing imaging-spectroscopy with a field of view of 8 x 8 arcmin2. The HXI is attached beneath the Wide Field Imager (WFI) covering 0.1-15 keV. Combined with the super-mirror coating on the mirror assembly, this configuration provides observation of X-ray source in wide energy band (0.1-40.0 keV) simultaneously, which is especially important for varying sources. The HXI sensor part consists of the semiconductor imaging spectrometer, using Si in the medium energy detector and CdTe in the high energy detector as its material, and an active shield covering its back to reduce background in orbit. The HXI technology is based on those of the Japanese-lead new generation X-ray observatory ASTRO-H, and partly from those developed for Simbol-X. Therefore, the technological development is in good progress. In the IXO mission, HXI will provide a major assets to identify the nature of the object by penetrating into thick absorbing materials and determined the inherent spectral shape in the energy band well above the structure around Fe-K lines and edges.

History of Hubble Space Telescope (HST)

NASA Image and Video Library

1986-01-01

This image illustrates the Hubble Space Telescope's (HST's) Optical Telescope Assembly (OTA). One of the three major elements of the HST, the OTA consists of two mirrors (a primary mirror and a secondary mirror), support trusses, and the focal plane structure. The mirrors collect and focus light from selected celestial objects and are housed near the center of the telescope. The primary mirror captures light from objects in space and focuses it toward the secondary mirror. The secondary mirror redirects the light to a focal plane where the Scientific Instruments are located. The primary mirror is 94.5 inches (2.4 meters) in diameter and the secondary mirror is 12.2 inches (0.3 meters) in diameter. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth Orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from the Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The spacecraft is 42.5 feet (13 meters) long and weighs 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

The Development of Stacked Core Technology for the Fabrication of Deep Lightweight UV-quality Space Mirrors

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Kirk, Charles S.; Maffett, Steven P.; Abplanalp, Calvin E.; Stahl, H. Philip; Effinger, Michael R.

2013-01-01

The Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. Under Science and Technology funding, NASA's Marshall Space Flight Center (MSFC) and Exelis have developed a more cost effective process to make up to 4m monolithic spaceflight UV quality, low areal density, thermally and dynamically stable primary mirrors. A proof of concept mirror was completed at Exelis and tested down to 250K at MSFC which would allow imaging out to 2.5 microns. The parameters and test results of this concept mirror will be shown. The scale-up process will be discussed and the technology development path to a 4m mirror system by 2018 will also be outlined.

Development of Stacked Core Technology for the Fabrication of Deep Lightweight UV Quality Space Mirrors

NASA Technical Reports Server (NTRS)

Matthews, Gary; Kirk, Charlie; Maffett, Steve; Abplanalp, Cal; Stahl, H. Philip

2013-01-01

Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. Under Science and Technology funding, NASA's Marshall Space Flight Center (MSFC) and ITT Exelis have developed a more cost effective process to make up to 4m monolithic spaceflight UV quality, low areal density, thermally and dynamically stable primary mirrors. A proof of concept mirror was completed at ITT Exelis and tested down to 250K at MSFC which would allow imaging out to 2.5 microns. The parameters and test results of this concept mirror will be shown. The scale-up process will be discussed and the technology development path to a 4m mirror system by 2018 will also be outlined.

Design and Analysis of Mirror Modules for IXO and Beyond

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; Powell, Cory; Saha, Timo T.; Zhang, William W.

2011-01-01

Advancements in X-ray astronomy demand thin, light, and closely packed thin optics which lend themselves to segmentation of the annular mirrors and, in turn, a modular approach to the mirror design. The functionality requirements of such a mirror module are well understood. A baseline modular concept for the proposed International X-Ray Observatory (IXO) Flight Mirror Assembly (FMA) consisting of 14,000 glass mirror segments divided into 60 modules was developed and extensively analyzed. Through this development, our understanding of module loads, mirror stress, thermal performance, and gravity distortion have greatly progressed. The latest progress in each of these areas is discussed herein. Gravity distortion during horizontal X-ray testing and on-orbit thermal performance have proved especially difficult design challenges. In light of these challenges, fundamental trades in modular X-ray mirror design have been performed. Future directions in module X-ray mirror design are explored including the development of a 1.8 m diameter FMA utilizing smaller mirror modules. The effect of module size on mirror stress, module self-weight distortion, thermal control, and range of segment sizes required is explored with advantages demonstrated from smaller module size in most cases.

Direct Polishing of Full-Shell, High-Resolution X-Ray Optics

NASA Technical Reports Server (NTRS)

Roche, Jacqueline M.; Gubarev, Mikhail V.; Smith, W. Scott; O'Dell, Stephen L.; Kolodziejczak, Jeffrey J.; Weisskopf, Martin C.; Ramsey, Brian D.; Elsner, Ronald F.

2014-01-01

Future x-ray telescopes will likely require lightweight mirrors to attain the large collecting areas needed to accomplish the science objectives. Understanding and demonstrating processes now is critical to achieving sub-arcsecond performance in the future. Consequently, designs not only of the mirrors but of fixtures for supporting them during fabrication, metrology, handling, assembly, and testing must be adequately modeled and verified. To this end, MSFC is using finite-element modeling to study the effects of mounting on thin, full-shell grazing-incidence mirrors, during all processes leading to a flight.

Commander Brand shaves in front of forward middeck lockers

NASA Technical Reports Server (NTRS)

1982-01-01

Commander Brand, wearing shorts, shaves in front of forward middeck lockers using personal hygiene mirror assembly (assy). Open modular locker single tray assy, Field Sequential (FS) crew cabin camera, communications kit assy mini headset (HDST) and HDST interface unit (HIU), personal hygiene kit, and meal tray assemblies appear in view.

JWST center of curvature test method and results

NASA Astrophysics Data System (ADS)

Saif, Babak; Chaney, David; Greenfield, Perry; Van Gorkom, Kyle; Brooks, Keira; Hack, Warren; Bluth, Marcel; Bluth, Josh; Sanders, James; Smith, Koby; Carey, Larkin; Chaung, Sze; Keski-Kuha, Ritva; Feinberg, Lee; Tournois, Severine; Smith, W. Scott; Kradinov, Vladimir

2017-09-01

The James Webb Space Telescope (JWST) recently saw the completion of the assembly process for the Optical Telescope Element and Integrated Science Instrument Module (OTIS). This integration effort was performed at Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. In conjunction with this assembly process a series of vibration and acoustic tests were performed. To help assure the telescope's primary mirror was not adversely impacted by this environmental testing an optical center of curvature (CoC) test was performed to measure changes in the mirror's optical performance. The primary is a 6.5 meter diameter mirror consisting of 18 individual hexagonal segments. Each segment is an off-axis asphere. There are a total of three prescriptions repeated six times each. As part of the CoC test each segment was individually measured using a high-speed interferometer (HSI) designed and built specifically for this test. This interferometer is capable of characterizing both static and dynamic characteristics of the mirrors. The latter capability was used, with the aid of a vibration stinger applying a low-level input force, to measure the dynamic characteristic changes of the PM backplane structure. This paper describes the CoC test setup, an innovative alignment method, and both static and dynamic test results.

SOFIA primary mirror fabrication and testing

NASA Astrophysics Data System (ADS)

Geyl, Roland; Tarreau, Michel; Plainchamp, Patrick

2001-12-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint American-German project dedicated to performing IR astronomy on board a Boeing Aircraft, in near space condition. First flight of the Observatory is planned for 2003. The REOSC Products Unit of SAGEM SA (France) has been contracted by Kayser Threde (Germany) for the design and fabrication of the 2.7-meter diameter, F/1.19 parabolic lightweight SOFIA primary mirror as well as the M3 dichroic and folding mirror assembly. This paper will report the design, fabrication and test of the lightweight primary mirror. The mirror structure has been obtained by machining it out from a solid Zerodur blank. It is the world's largest of this type today. Axial and lateral mirror support system has been conceptually designed and engineered by SAGEM-REOSC engineers in relation with Kayser Threde team. The optical surface is an F/1.19 parabola polished to a high level of quality.

System Architecture of Explorer Class Spaceborne Telescopes: A look at Optimization of Cost, Testability, Risk and Operational Duty Cycle from the Perspective of Primary Mirror Material Selection

NASA Astrophysics Data System (ADS)

Hull, Anthony B.; Westerhoff, Thomas

2015-01-01

Management of cost and risk have become the key enabling elements for compelling science to be done within Explorer or M-Class Missions. We trace how optimal primary mirror selection may be co-optimized with orbit selection. And then trace the cost and risk implications of selecting a low diffusivity low thermal expansion material for low and medium earth orbits, vs. high diffusivity high thermal expansion materials for the same orbits. We will discuss that ZERODUR®, a material that has been in space for over 30 years, is now available as highly lightweighted open-back mirrors, and the attributes of these mirrors in spaceborne optical telescope assemblies. Lightweight ZERODUR® solutions are practical from mirrors < 0.3m in diameter to >4m in diameter. An example of a 1.2m lightweight ZERODUR® mirror will be discussed.

Advanced Mirror Technology Development (AMTD) for Very Large Space Telescopes

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2014-01-01

Advanced Mirror Technology Development (AMTD) is a multi-year effort to systematically mature to TRL-6 the critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable mission can be considered by the 2020 Decadal Review. This technology must enable missions capable of both general astrophysics & ultra-high contrast observations of exoplanets. To accomplish our objective, We use a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system.

Directed Energy Technology Overview

DTIC Science & Technology

2011-06-01

with an AR coating, The primary mirror is zerodur on a 9 point mount incorporating a tuned mass damper.. The secondary, tertiary, and coude optics are...beam conditioning back end section: • A beam expander enlarges the beam and shapes it to fill the active area of a deformable mirror • Because of the...enabling technologies that would make a 100-kW SS laser possible (high power optical coatings, high power gain modules, deformable mirror technology

Analysis and testing of a soft actuation system for segmented reflector articulation and isolation

NASA Technical Reports Server (NTRS)

Jandura, Louise; Agronin, Michael L.

1991-01-01

Segmented reflectors have been proposed for space-based applications such as optical communication and large-diameter telescopes. An actuation system for mirrors in a space-based segmented mirror array has been developed as part of the National Aeronautics and Space Administration-sponsored Precision Segmented Reflector program. The actuation system, called the Articulated Panel Module (APM), articulates a mirror panel in 3 degrees of freedom in the submicron regime, isolates the panel from structural motion, and simplifies space assembly of the mirrors to the reflector backup truss. A breadboard of the APM has been built and is described. Three-axis modeling, analysis, and testing of the breadboard is discussed.

JWST Pathfinder Telescope Integration

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.;

Development Tests of a Cryogenic Filter Wheel Assembly for the NIRCam Instrument

NASA Technical Reports Server (NTRS)

McCully, Sean; Clark, Charles; Schermerhorn, Michael; Trojanek, Filip; O'Hara, Mark; Williams, Jeff; Thatcher, John

2006-01-01

The James Webb Space Telescope is an infrared-optimized space telescope scheduled for launch in 201 3. Its 6.5-m diameter primary mirror will collect light from some of the first galaxies formed after the big bang. The Near Infrared camera (NIRCam) will detect the first light from these galaxies, provide the necessary tools for studying the formation of stars, aid in discovering planets around other stars, and adjust the wave front error on the primary mirror (Fig. 1). The instrument and its complement of mechanisms and optics will operate at a cryogenic temperature of 35 K. This paper describes tests and test results of the NIRCam Filter Wheel assembly prototype.

Lightweight ZERODUR mirror blanks: recent advances supporting faster, cheaper, and better spaceborne optical telescope assemblies

NASA Astrophysics Data System (ADS)

Hull, Tony; Westerhoff, Thomas

2014-10-01

While there is no single material solution ideal for all missions, recent advances by SCHOTT in fabricating lightweight mirror blanks makes ZERODUR® a highly viable solution for many spaceborne telescopes. ZERODUR® is a well-characterized very low-expansion material. Monolithic mirrors are made without bonding or fusing out of highly homogeneous and isotropic blanks currently available in sizes up to 4m plus. We will summarize results recently given in a series of papers on the characteristics of these lightweight mirror blanks in sizes from 0.3m up, and describe the method of blank fabrication, with its compatibility to contemporary optical fabrication techniques that control of all optical spatial frequencies. ZERODUR® has a 35 year heritage in space on numerous missions, including the secondary mirror of Hubble, and all the Chandra mirrors. With the lightweighting we will discuss, ZERODUR® is now a high performing, affordable and rapidly produced mirror substrate suitable for lightweight imaging telescopes.

Czechoslovak Replica X-Ray Mirrors for Astronomical Applications

NASA Astrophysics Data System (ADS)

Hudec, R.; Valnicek, B.

Imaging X-ray mirrors has been developed in Czechoslovakia since 1970 by a way of two different replica technologies based on galvanoplastics and reactoplastics as a natural part of Czechoslovak X-ray astronomy program. Until now about 30 mirros with diameters between 1.7 and 24 cm were manufactured. Seven mirrors were flown in space experiments. The new technology used since 1981 allows to produce light-weight X-ray mirrors at relatively very low cost. The technology offers interesting possibilities in construction of (1) large arrays of identical optical systems, (2) very small (microscopic) mirros and (3) lobster-eye type optics. Advantages and drawbacks of replica techology are discussed.

Thin Mirror Shaping Technology for High-Throughput X-ray Telescopes

NASA Astrophysics Data System (ADS)

Schattenburg, Mark

This proposal is submitted to the NASA Research Opportunities in Space and Earth Sciences program (ROSES-2012) in response to NASA Research Announcement NNH12ZDA001N- APRA. It is targeted to the Astronomy and Astrophysics Research and Analysis (APRA) program element under the Supporting Technology category. Powerful x-ray telescope mirrors are critical components of a raft of small-to-large mission concepts under consideration by NASA. The science questions addressed by these missions have certainly never been more compelling and the need to fulfill NASA s core missions of exploring the universe and strengthening our nation s technology base has never been greater. Unfortunately, budgetary constraints are driving NASA to consider the cost/benefit and risk factors of new missions more carefully than ever. New technology for producing x-ray telescopes with increased resolution and collecting area, while holding down cost, are key to meeting these goals and sustaining a thriving high-energy astrophysics enterprise in the US. We propose to develop advanced technology which will lead to thin-shell x-ray telescope mirrors rivaling the Chandra x-ray telescope in spatial resolution but with 10-100X larger area all at significantly reduced weight, risk and cost. The proposed effort builds on previous research at MIT and complements NASA-supported research at other institutions. We are currently pursuing two thin-mirror technology development tracks which we propose to extend and accelerate with NASA support. The first research track utilizes rapidly-maturing thermal glass slumping technology which uses porous ceramic air-bearing mandrels to shape glass mirrors without touching, thus avoiding surface-induced mid-range spatial frequency ripples. A second research track seeks to remove any remaining mid- to long-range errors in mirrors by using scanning ion-beam implant to impart small, highly deterministic and very stable amounts of stress into thin glass, utilizing local bending moments to correct mirror shape. Preliminary results from our lab demonstrate the simplicity, specificity, and exquisite sensitivity of this technique on silicon and glass wafers. We believe that the combination of these new technologies has the potential to revolutionize thin mirror shaping technology and will enable a renaissance in high-energy astrophysics.

Advanced technology optical telescopes IV; Proceedings of the Meeting, Tucson, AZ, Feb. 12-16, 1990. Parts 1 & 2

NASA Technical Reports Server (NTRS)

Barr, Lawrence D. (Editor)

1990-01-01

The present conference on the current status of large, advanced-technology optical telescope development and construction projects discusses topics on such factors as their novel optical system designs, the use of phased arrays, seeing and site performance factors, mirror fabrication and testing, pointing and tracking techniques, mirror thermal control, structural design strategies, mirror supports and coatings, and the control of segmented mirrors. Attention is given to the proposed implementation of the VLT Interferometer, the first diffraction-limited astronomical images with adaptive optics, a fiber-optic telescope using a large cross-section image-transmitting bundle, the design of wide-field arrays, Hartmann test data reductions, liquid mirrors, inertial drives for telescope pointing, temperature control of large honeycomb mirrors, evaporative coatings for very large telescope mirrors, and the W. M. Keck telescope's primary mirror active control system software.

Kodak AMSD Mirror Development Program

NASA Technical Reports Server (NTRS)

Matthews, Gary; Dahl, Roger; Barrett, David; Bottom, John; Russell, Kevin (Technical Monitor)

2002-01-01

The Advanced Mirror System Demonstration Program is developing minor technology for the next generation optical systems. Many of these systems will require extremely lightweight and stable optics due to the overall size of the primary mirror. These segmented, deployable systems require new technology that AMSD is developing. The on-going AMSD program is a critical enabler for Next Generation Space Telescope (NGST) which will start in 2002. The status of Kodak's AMSD mirror and future plans will be discussed with respect to the NGST program.

Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yashchuk, Valeriy V.; Morrison, Gregory Y.; Marcus, Matthew A.

The Advanced Light Source (ALS) beamline (BL) 10.3.2 is an apparatus for X-ray microprobe spectroscopy and diffraction experiments, operating in the energy range 2.4–17 keV. The performance of the beamline, namely the spatial and energy resolutions of the measurements, depends significantly on the collimation quality of light incident on the monochromator. In the BL 10.3.2 end-station, the synchrotron source is imaged 1:1 onto a set of roll slits which form a virtual source. The light from this source is collimated in the vertical direction by a bendable parabolic cylinder mirror. Details are presented of the mirror design, which allows formore » precision assembly, alignment and shaping of the mirror, as well as for extending of the mirror operating lifetime by a factor of ~10. Assembly, mirror optimal shaping and preliminary alignment were performed ex situ in the ALS X-ray Optics Laboratory (XROL). Using an original method for optimal ex situ characterization and setting of bendable X-ray optics developed at the XROL, a root-mean-square (RMS) residual surface slope error of 0.31 µrad with respect to the desired parabola, and an RMS residual height error of less than 3 nm were achieved. Once in place at the beamline, deviations from the designed optical geometry ( e.g. due to the tolerances for setting the distance to the virtual source, the grazing incidence angle, the transverse position) and/or mirror shape ( e.g. due to a heat load deformation) may appear. Due to the errors, on installation the energy spread from the monochromator is typically a few electron-volts. Here, a new technique developed and successfully implemented for at-wavelength ( in situ) fine optimal tuning of the mirror, enabling us to reduce the collimation-induced energy spread to ~0.05 eV, is described.« less

Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2

PubMed Central

Yashchuk, Valeriy V.; Morrison, Gregory Y.; Marcus, Matthew A.; Domning, Edward E.; Merthe, Daniel J.; Salmassi, Farhad; Smith, Brian V.

2015-01-01

The Advanced Light Source (ALS) beamline (BL) 10.3.2 is an apparatus for X-ray microprobe spectroscopy and diffraction experiments, operating in the energy range 2.4–17 keV. The performance of the beamline, namely the spatial and energy resolutions of the measurements, depends significantly on the collimation quality of light incident on the monochromator. In the BL 10.3.2 end-station, the synchrotron source is imaged 1:1 onto a set of roll slits which form a virtual source. The light from this source is collimated in the vertical direction by a bendable parabolic cylinder mirror. Details are presented of the mirror design, which allows for precision assembly, alignment and shaping of the mirror, as well as for extending of the mirror operating lifetime by a factor of ∼10. Assembly, mirror optimal shaping and preliminary alignment were performed ex situ in the ALS X-ray Optics Laboratory (XROL). Using an original method for optimal ex situ characterization and setting of bendable X-ray optics developed at the XROL, a root-mean-square (RMS) residual surface slope error of 0.31 µrad with respect to the desired parabola, and an RMS residual height error of less than 3 nm were achieved. Once in place at the beamline, deviations from the designed optical geometry (e.g. due to the tolerances for setting the distance to the virtual source, the grazing incidence angle, the transverse position) and/or mirror shape (e.g. due to a heat load deformation) may appear. Due to the errors, on installation the energy spread from the monochromator is typically a few electron-volts. Here, a new technique developed and successfully implemented for at-wavelength (in situ) fine optimal tuning of the mirror, enabling us to reduce the collimation-induced energy spread to ∼0.05 eV, is described. PMID:25931083

Performance optimization of a bendable parabolic cylinder collimating X-ray mirror for the ALS micro-XAS beamline 10.3.2

DOE PAGES

Yashchuk, Valeriy V.; Morrison, Gregory Y.; Marcus, Matthew A.; ...

2015-04-08

The Advanced Light Source (ALS) beamline (BL) 10.3.2 is an apparatus for X-ray microprobe spectroscopy and diffraction experiments, operating in the energy range 2.4–17 keV. The performance of the beamline, namely the spatial and energy resolutions of the measurements, depends significantly on the collimation quality of light incident on the monochromator. In the BL 10.3.2 end-station, the synchrotron source is imaged 1:1 onto a set of roll slits which form a virtual source. The light from this source is collimated in the vertical direction by a bendable parabolic cylinder mirror. Details are presented of the mirror design, which allows formore » precision assembly, alignment and shaping of the mirror, as well as for extending of the mirror operating lifetime by a factor of ~10. Assembly, mirror optimal shaping and preliminary alignment were performed ex situ in the ALS X-ray Optics Laboratory (XROL). Using an original method for optimal ex situ characterization and setting of bendable X-ray optics developed at the XROL, a root-mean-square (RMS) residual surface slope error of 0.31 µrad with respect to the desired parabola, and an RMS residual height error of less than 3 nm were achieved. Once in place at the beamline, deviations from the designed optical geometry ( e.g. due to the tolerances for setting the distance to the virtual source, the grazing incidence angle, the transverse position) and/or mirror shape ( e.g. due to a heat load deformation) may appear. Due to the errors, on installation the energy spread from the monochromator is typically a few electron-volts. Here, a new technique developed and successfully implemented for at-wavelength ( in situ) fine optimal tuning of the mirror, enabling us to reduce the collimation-induced energy spread to ~0.05 eV, is described.« less

Meta-shell Approach for Constructing Lightweight and High Resolution X-Ray Optics

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.

2016-01-01

Lightweight and high resolution optics are needed for future space-based x-ray telescopes to achieve advances in high-energy astrophysics. Past missions such as Chandra and XMM-Newton have achieved excellent angular resolution using a full shell mirror approach. Other missions such as Suzaku and NuSTAR have achieved lightweight mirrors using a segmented approach. This paper describes a new approach, called meta-shells, which combines the fabrication advantages of segmented optics with the alignment advantages of full shell optics. Meta-shells are built by layering overlapping mirror segments onto a central structural shell. The resulting optic has the stiffness and rotational symmetry of a full shell, but with an order of magnitude greater collecting area. Several meta-shells so constructed can be integrated into a large x-ray mirror assembly by proven methods used for Chandra and XMM-Newton. The mirror segments are mounted to the meta-shell using a novel four point semi-kinematic mount. The four point mount deterministically locates the segment in its most performance sensitive degrees of freedom. Extensive analysis has been performed to demonstrate the feasibility of the four point mount and meta-shell approach. A mathematical model of a meta-shell constructed with mirror segments bonded at four points and subject to launch loads has been developed to determine the optimal design parameters, namely bond size, mirror segment span, and number of layers per meta-shell. The parameters of an example 1.3 m diameter mirror assembly are given including the predicted effective area. To verify the mathematical model and support opto-mechanical analysis, a detailed finite element model of a meta-shell was created. Finite element analysis predicts low gravity distortion and low thermal distortion. Recent results are discussed including Structural Thermal Optical Performance (STOP) analysis as well as vibration and shock testing of prototype meta-shells.

Status of the Advanced Mirror Technology Development (AMTD) Phase 2, 1.5m ULE(Registered Trademark) Mirror

NASA Technical Reports Server (NTRS)

Egerman, Robert; Matthews, Gary W.; Johnson, Matthew; Ferland, Albert; Stahl, H. Philip; Eng, Ron; Effinger, Michael R.

2015-01-01

The Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. Under Science and Technology funding, NASA's Marshall Space Flight Center (MSFC) and Exelis have developed a more cost effective process to make up to 4m monolithic spaceflight UV quality, low areal density, thermally and dynamically stable primary mirrors. Under a Phase I program, a proof of concept mirror was completed at Exelis and tested down to 250K at MSFC which would allow imaging out to 2.5 microns. In 2014, Exelis and NASA started a Phase II program to design and build a 1.5m mirror to demonstrate lateral scalability to a 4m monolithic primary mirror. The current status of the Phase II development program will be provided along with a Phase II program summary.

Mirror Technology

NASA Technical Reports Server (NTRS)

1992-01-01

Under a NASA contract, MI-CVD developed a process for producing bulk silicon carbide by means of a chemical vapor deposition process. The technology allows growth of a high purity material with superior mechanical/thermal properties and high polishability - ideal for mirror applications. The company employed the technology to develop three research mirrors for NASA Langley and is now marketing it as CVD SILICON CARBIDE. Its advantages include light weight, thermal stability and high reflectivity. The material has nuclear research facility applications and is of interest to industrial users of high power lasers.

Cost-optimized methods extending the solution space of lightweight spaceborne monolithic ZERODUR® mirrors to larger sizes

NASA Astrophysics Data System (ADS)

Leys, Antoine; Hull, Tony; Westerhoff, Thomas

2015-09-01

We address the problem that larger spaceborne mirrors require greater sectional thickness to achieve a sufficient first eigen frequency that is resilient to launch loads, and to be stable during optical telescope assembly integration and test, this added thickness results in unacceptable added mass if we simply scale up solutions for smaller mirrors. Special features, like cathedral ribs, arch, chamfers, and back-side following the contour of the mirror face have been considered for these studies. For computational efficiency, we have conducted detailed analysis on various configurations of a 800 mm hexagonal segment and of a 1.2-m mirror, in a manner that they can be constrained by manufacturing parameters as would be a 4-m mirror. Furthermore each model considered also has been constrained by cost-effective machining practice as defined in the SCHOTT Mainz factory. Analysis on variants of this 1.2-m mirror has shown a favorable configuration. We have then scaled this optimal configuration to 4-m aperture. We discuss resulting parameters of costoptimized 4-m mirrors. We also discuss the advantages and disadvantages this analysis reveals of going to cathedral rib architecture on 1-m class mirror substrates.

Wavefront Sensing Analysis of Grazing Incidence Optical Systems

NASA Technical Reports Server (NTRS)

Rohrbach, Scott; Saha, Timo

2012-01-01

Wavefront sensing is a process by which optical system errors are deduced from the aberrations in the image of an ideal source. The method has been used successfully in near-normal incidence, but not for grazing incidence systems. This innovation highlights the ability to examine out-of-focus images from grazing incidence telescopes (typically operating in the x-ray wavelengths, but integrated using optical wavelengths) and determine the lower-order deformations. This is important because as a metrology tool, this method would allow the integration of high angular resolution optics without the use of normal incidence interferometry, which requires direct access to the front surface of each mirror. Measuring the surface figure of mirror segments in a highly nested x-ray telescope mirror assembly is difficult due to the tight packing of elements and blockage of all but the innermost elements to normal incidence light. While this can be done on an individual basis in a metrology mount, once the element is installed and permanently bonded into the assembly, it is impossible to verify the figure of each element and ensure that the necessary imaging quality will be maintained. By examining on-axis images of an ideal point source, one can gauge the low-order figure errors of individual elements, even when integrated into an assembly. This technique is known as wavefront sensing (WFS). By shining collimated light down the optical axis of the telescope and looking at out-of-focus images, the blur due to low-order figure errors of individual elements can be seen, and the figure error necessary to produce that blur can be calculated. The method avoids the problem of requiring normal incidence access to the surface of each mirror segment. Mirror figure errors span a wide range of spatial frequencies, from the lowest-order bending to the highest order micro-roughness. While all of these can be measured in normal incidence, only the lowest-order contributors can be determined through this WFS technique.

AXAF Alignment Test System Autocollimating Flat Error Correction

NASA Technical Reports Server (NTRS)

Lewis, Timothy S.

1995-01-01

The alignment test system for the advanced x ray astrophysics facility (AXAF) high-resolution mirror assembly (HRMA) determines the misalignment of the HRMA by measuring the displacement of a beam of light reflected by the HRMA mirrors and an autocollimating flat (ACF). This report shows how to calibrate the system to compensate for errors introduced by the ACF, using measurements taken with the ACF in different positions. It also shows what information can be obtained from alignment test data regarding errors in the shapes of the HRMA mirrors. Simulated results based on measured ACF surface data are presented.

A normal incidence, high resolution X-ray telescope for solar coronal observations

NASA Technical Reports Server (NTRS)

Golub, L.

1985-01-01

The following major activities were advanced or completed: complete design of the entire telescope assembly and fabrication of all front-end components; specification of all rocket skin sections including bulkheads, feedthroughs and access door; fabrication, curing, and delivery of the large graphite-epoxy telescope tube; engineering analysis of the primary mirror vibration test was completed and a decision made to redesign the mirror attachment to a kinematic three-point mount; detail design of the camera control, payload and housekeeping electronics; and multilayer mirror flats with 2d spacings of 50 A and 60 A.

Constructing a dispersed fringe sensor prototype for the Giant Magellan Telescope

NASA Astrophysics Data System (ADS)

Frostig, Danielle; McLeod, Brian; AGWS Team

2018-01-01

The Giant Magellan Telescope (GMT) will be the world’s largest telescope upon completion. The GMT employs seven 8 m primary mirror segments and seven 1 m secondary mirror segments. One challenge of the GMT is keeping the seven pairs of mirror segments on the GMT in phase. In this project, we developed and began assembly on a design for a dispersed fringe sensor prototype consisting of an optical and basic mechanical layout. The prototype design will be tested on the Magellan Clay Telescope as an experiment for future phasing methods to be used on the GMT.

Ethylene glycol contamination effects on first surface aluminized mirrors

NASA Astrophysics Data System (ADS)

Dunlop, Patrick; Probst, Ronald G.; Evatt, Matthew; Reddell, Larry; Sprayberry, David

2016-07-01

The Dark Energy Spectroscopic Instrument (DESI) is under construction for installation on the Mayall 4 Meter telescope. The use of a liquid cooling system is proposed to maintain the DESI prime focus assembly temperature within ±1°C of ambient. Due to concerns of fluid deposition onto optical surfaces from possible leaks, systematic tests were performed of the effects on first surface aluminized mirrors of ethylene glycol and two other candidate coolants. Objective measurement of scattering and reflectivity was an important supplement to visual inspection. Rapid cleanup of a coolant spill followed by a hand wash of the mirror limited surface degradation to the equivalent of a few months of general environmental exposure. Prolonged exposure to corrosive coolants dissolved the aluminum, necesitating mirror recoating.

Mirrors design, analysis and manufacturing of the 550mm Korsch telescope experimental model

NASA Astrophysics Data System (ADS)

Huang, Po-Hsuan; Huang, Yi-Kai; Ling, Jer

2017-08-01

In 2015, NSPO (National Space Organization) began to develop the sub-meter resolution optical remote sensing instrument of the next generation optical remote sensing satellite which follow-on to FORMOSAT-5. Upgraded from the Ritchey-Chrétien Cassegrain telescope optical system of FORMOSAT-5, the experimental optical system of the advanced optical remote sensing instrument was enhanced to an off-axis Korsch telescope optical system which consists of five mirrors. It contains: (1) M1: 550mm diameter aperture primary mirror, (2) M2: secondary mirror, (3) M3: off-axis tertiary mirror, (4) FM1 and FM2: two folding flat mirrors, for purpose of limiting the overall volume, reducing the mass, and providing a long focal length and excellent optical performance. By the end of 2015, we implemented several important techniques including optical system design, opto-mechanical design, FEM and multi-physics analysis and optimization system in order to do a preliminary study and begin to develop and design these large-size lightweight aspheric mirrors and flat mirrors. The lightweight mirror design and opto-mechanical interface design were completed in August 2016. We then manufactured and polished these experimental model mirrors in Taiwan; all five mirrors ware completed as spherical surfaces by the end of 2016. Aspheric figuring, assembling tests and optical alignment verification of these mirrors will be done with a Korsch telescope experimental structure model in 2018.

BESST: A Miniature, Modular Radiometer

NASA Technical Reports Server (NTRS)

Warden, Robert; Good, William; Baldwin-Stevens, Erik

2010-01-01

A new radiometer assembly has been developed that incorporates modular design principles in order to provide flexibility and versatility. The assembly, shown in Figure 1, is made up of six modules plus a central cubical frame. A small thermal imaging detector is used to determine the temperature of remote objects. To improve the accuracy of the temperature reading, frequent calibration is required. The detector must view known temperature targets before viewing the remote object. Calibration is achieved by using a motorized fold mirror to select the desired scene the detector views. The motor steps the fold mirror through several positions, which allows the detector to view the calibration targets or the remote object. The details, features, and benefits of the radiometer are described in this paper.

Toward Active X-ray Telescopes II

NASA Technical Reports Server (NTRS)

O'Dell, Stephen L.; Aldroft, Thomas L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.;

SiC lightweight telescopes for advanced space applications. I - Mirror technology

NASA Technical Reports Server (NTRS)

Anapol, Michael I.; Hadfield, Peter

1992-01-01

A SiC based telescope is an extremely attractive emerging technology which offers the lightweight and stiffness features of beryllium, the optical performance of glass to diffraction limited visible resolution, superior optical/thermal stability to cryogenic temperatures, and the cost advantages of an aluminum telescope. SSG has developed various SiC mirrors with and without a silicon coating and tested these mirrors over temperature ranges from +50 C to -250 C. Our test results show less than 0.2 waves P-V in visible wavefront change and no hysteresis over this wide temperature range. Several SSG mirrors are representative of very lightweight SiC/Si mirrors including (1) a 9 cm diameter, high aspect ratio mirror weighing less than 30 grams and (2) a 23 cm diameter eggcrated mirror weighing less than 400 grams. SSG has also designed and analyzed a 0.6 meter SiC based, on axis, three mirror reimaging telescope in which the primary mirror weighs less than 6 kg and a 0.5 meter GOES-like scan mirror. SSG has also diamond turned several general aspheric SiC/Si mirrors with excellent cryo optical performance.

Research on stretched membrane with electrostatic curvature (SMEC) mirrors

NASA Astrophysics Data System (ADS)

Sun, X. W.; Jin, G.

Stretched Membrane with Electrostatic Curvature SMEC Mirrors is a new spatial optical technology recently developed in foreign countries which performed modification of figuration of SMEC Mirror in control of Electrostatic With the folding property of membrane when it was loaded this technology have taken on important prospect in system of spatial remote sensing in the future In this paper the fundamental of SMEC Mirror was introduced the more deeply analyzing of cybernetic model completed and at present research method based on synthesis of foreign development in the field was put forward

A cryogenic 'set-and-forget' deformable mirror

NASA Astrophysics Data System (ADS)

Trines, Robin; Janssen, Huub; Paalvast, Sander; Teuwen, Maurice; Brandl, Bernhard; Rodenhuis, Michiel

2016-07-01

This paper discusses the development, realization and initial characterization of a demonstrator for a cryogenic 'set and forget' deformable mirror. Many optical and cryogenic infrared instruments on modern very and extremely large telescopes aim at diffraction-limited performance and require total wave front errors in the order of 50 nanometers or less. At the same time, their complex optical functionality requires either a large number of spherical mirrors or several complex free-form mirrors. Due to manufacturing and alignment tolerances, each mirror contributes static aberrations to the wave front. Many of these aberrations are not known in the design phase and can only be measured once the system has been assembled. A 'set-and-forget' deformable mirror can be used to compensate for these aberrations, making it especially interesting for systems with complex free-form mirrors or cryogenic systems where access to iterative realignment is very difficult or time consuming. The mirror with an optical diameter of 200 mm is designed to correct wave front aberrations of up to 2 μm root-mean square (rms). The shape of the wave front is approximated by the first 15 Zernike modes. Finite element analysis of the mirror shows a theoretically possible reduction of the wave front error from 2 μm to 53 nm rms. To produce the desired shapes, the mirror surface is controlled by 19 identical actuator modules at the back of the mirror. The actuator modules use commercially available Piezo-Knob actuators with a high technology readiness level (TRL). These provide nanometer resolution at cryogenic temperatures combined with high positional stability, and allow for the system to be powered off once the desired shape is obtained. The stiff design provides a high resonance frequency (>200 Hz) to suppress external disturbances. A full-size demonstrator of the deformable mirror containing 6 actuators and 13 dummy actuators is realized and characterized. Measurement results show that the actuators can provide sufficient stroke to correct the 2 μm rms WFE. The resolution of the actuator influence functions is found to be 0.24 nm rms or better depending on the position of the actuator within the grid. Superposition of the actuator influence functions shows that a 2 μm rms WFE can be accurately corrected with a 38 nm fitting error. Due to the manufacturing method of the demonstrator an artificially large print-through error of 182 nm is observed. The main cause of this print-through error has been identified and will be reduced in future design iterations. After these design changes the system is expected to have a total residual error of less than 70 nm and offer diffraction limited performance (λ14) for wavelengths of 1 μm and above.

A Parametric Finite-Element Model for Evaluating Segmented Mirrors with Discrete, Edgewise Connectivity

NASA Technical Reports Server (NTRS)

Gersh-Range, Jessica A.; Arnold, William R.; Peck, Mason A.; Stahl, H. Philip

2011-01-01

Since future astrophysics missions require space telescopes with apertures of at least 10 meters, there is a need for on-orbit assembly methods that decouple the size of the primary mirror from the choice of launch vehicle. One option is to connect the segments edgewise using mechanisms analogous to damped springs. To evaluate the feasibility of this approach, a parametric ANSYS model that calculates the mode shapes, natural frequencies, and disturbance response of such a mirror, as well as of the equivalent monolithic mirror, has been developed. This model constructs a mirror using rings of hexagonal segments that are either connected continuously along the edges (to form a monolith) or at discrete locations corresponding to the mechanism locations (to form a segmented mirror). As an example, this paper presents the case of a mirror whose segments are connected edgewise by mechanisms analogous to a set of four collocated single-degree-of-freedom damped springs. The results of a set of parameter studies suggest that such mechanisms can be used to create a 15-m segmented mirror that behaves similarly to a monolith, although fully predicting the segmented mirror performance would require incorporating measured mechanism properties into the model. Keywords: segmented mirror, edgewise connectivity, space telescope

Pilot Overmyer looks over food selections and experiments with beverage

NASA Image and Video Library

1982-11-16

STS005-07-255 (19 Nov. 1982) --- Astronaut Robert F. Overmyer, STS-5 pilot, using beverage container and drinking straw secured in meal tray assembly (ASSY), experiments with microgravity characteristics of liquid on middeck in front of forward lockers. Overmyer also looks over packages of food attached to middeck lockers in meal tray assemblies. Carry-on food warmer appears overhead and other meal tray assemblies, personal hygiene mirror assembly, personal hygiene kit, and portrait of G.W.S. Abbey, Johnson Space Center's (JSC) Director of Flight Operations, appear on lockers. Photo credit: NASA

SiC Design Guide: Manufacture of Silicon Carbide Products (Briefing charts)

DTIC Science & Technology

2010-06-08

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. 13. SUPPLEMENTARY NOTES Presented at Mirror Technology Days, Boulder...coatings. 15. SUBJECT TERMS Mirrors , structures, silicon carbide, design, inserts, coatings, pockets, ribs, bonding, threads 16. SECURITY...Prescribed by ANSI Std. 239.18 purify protect transport SiC Design Guide Manufacture of Silicon Carbide Products Mirror Technology Days June 7 to 9, 2010

Screening of a virtual mirror-image library of natural products.

PubMed

Noguchi, Taro; Oishi, Shinya; Honda, Kaori; Kondoh, Yasumitsu; Saito, Tamio; Ohno, Hiroaki; Osada, Hiroyuki; Fujii, Nobutaka

2016-06-08

We established a facile access to an unexplored mirror-image library of chiral natural product derivatives using d-protein technology. In this process, two chemical syntheses of mirror-image substances including a target protein and hit compound(s) allow the lead discovery from a virtual mirror-image library without the synthesis of numerous mirror-image compounds.

The meter-class carbon fiber reinforced polymer mirror and segmented mirror telescope at the Naval Postgraduate School

NASA Astrophysics Data System (ADS)

Wilcox, Christopher; Fernandez, Bautista; Bagnasco, John; Martinez, Ty; Romeo, Robert; Agrawal, Brij

2015-03-01

The Adaptive Optics Center of Excellence for National Security at the Naval Postgraduate School has implemented a technology testing platform and array of facilities for next-generation space-based telescopes and imaging system development. The Segmented Mirror Telescope is a 3-meter, 6 segment telescope with actuators on its mirrors for system optical correction. Currently, investigation is being conducted in the use of lightweight carbon fiber reinforced polymer structures for large monolithic optics. Advantages of this material include lower manufacturing costs, very low weight, and high durability and survivability compared to its glass counterparts. Design and testing has begun on a 1-meter, optical quality CFRP parabolic mirror for the purpose of injecting collimated laser light through the SMT primary and secondary mirrors as well as the following aft optics that include wavefront sensors and deformable mirrors. This paper will present the design, testing, and usage of this CFRP parabolic mirror and the current path moving forward with this ever-evolving technology.

A normal incidence, high resolution X-ray telescope for solar coronal observations

NASA Technical Reports Server (NTRS)

Golub, L.

1984-01-01

A Normal Incidence high resolution X-ray Telescope is reported. The design of a telescope assembly which, after fabrication, will be integrated with the mirror fabrication process is described. The assembly is engineered to fit into the Black Brant rocket skin to survive sounding rocket launch conditions. A flight ready camera is modified and tested.

Spherical mirror mount

NASA Technical Reports Server (NTRS)

Meyer, Jay L. (Inventor); Messick, Glenn C. (Inventor); Nardell, Carl A. (Inventor); Hendlin, Martin J. (Inventor)

2011-01-01

A spherical mounting assembly for mounting an optical element allows for rotational motion of an optical surface of the optical element only. In that regard, an optical surface of the optical element does not translate in any of the three perpendicular translational axes. More importantly, the assembly provides adjustment that may be independently controlled for each of the three mutually perpendicular rotational axes.

Atomic Layer Deposition Re Ective Coatings For Future Astronomical Space Telescopes And The Solar Corona Viewed Through The Minxss (Miniature X-Ray Solar Spectrometer) Cubesats

NASA Astrophysics Data System (ADS)

Moore, Christopher Samuel

2017-11-01

Advances in technology and instrumentation open new windows for observing astrophysical objects. The first half of my dissertation involves the development of atomic layer deposition (ALD) coatings to create high reflectivity UV mirrors for future satellite astronomical telescopes. Aluminum (Al) has intrinsic reflectance greater than 80% from 90 – 2,000 nm, but develops a native aluminum oxide (Al2O3) layer upon exposure to air that readily absorbs light below 250 nm. Thus, Al based UV mirrors must be protected by a transmissive overcoat. Traditionally, metal-fluoride overcoats such as MgF2 and LiF are used to mitigate oxidation but with caveats. We utilize a new metal fluoride (AlF3) to protect Al mirrors deposited by ALD. ALD allows for precise thickness control, conformal and near stoichiometric thin films. We prove that depositing ultra-thin ( 3 nm) ALD ALF3 to protect Al mirrors after removing the native oxide layer via atomic layer etching (ALE) enhances the reflectance near 90 nm from 5% to 30%.X-ray detector technology with high readout rates are necessary for the relatively bright Sun, particularly during large flares. The hot plasma in the solar corona generates X-rays, which yield information on the physical conditions of the plasma. The second half of my dissertation includes detector testing, characterization and solar science with the Miniature X-ray Solar Spectrometer (MinXSS) CubeSats. The MinXSS CubeSats employ Silicon Drift Diode (SDD) detectors called X123, which generate full sun spectrally resolved ( 0.15 FWHM at 5.9 keV) measurements of the sparsely measured, 0.5 – 12 keV range. The absolute radiometric calibration of the MinXSS instrument suite was performed at the National Institute for Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF) and spectral resolution determined from radioactive sources. I used MinXSS along with data from the Geostationary Operational Environmental Satellites (GOES), Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), Hinode X-ray Telescope (XRT), Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) and Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) to study the solar corona. This resulted in new insights on the coronal temperature distribution and elemental abundance variations for quiescence, active regions and during solar flares.

Silicon carbide as a basis for spaceflight optical systems

NASA Astrophysics Data System (ADS)

Curcio, Michael E.

1994-09-01

New advances in the areas of microelectronics and micro-mechanical devices have created a momentum in the development of lightweight, miniaturized, electro-optical space subsystems. The performance improvements achieved and new observational techniques developed as a result, have provided a basis for a new range of Small Explorer, Discovery-class and other low-cost mission concepts for space exploration. However, the ultimate objective of low-mass, inexpensive space science missions will only be achieved with a companion development in the areas of flight optical systems and sensor instrument benches. Silicon carbide (SiC) is currently emerging as an attractive technology to fill this need. As a material basis for reflective, flight telescopes and optical benches, SiC offers: the lightweight and stiffness characteristics of beryllium; glass-like inherent stability consistent with performance to levels of diffraction-limited visible resolution; superior thermal properties down to cryogenic temperatures; and an existing, commercially-based material and processing infrastructure like aluminum. This paper will describe the current status and results of on-going technology developments to utilize these material properties in the creation of lightweight, high- performing, thermally robust, flight optical assemblies. System concepts to be discussed range from an 18 cm aperture, 4-mirror, off-axis system weighing less than 2 kg to a 0.5 m, 15 kg reimager. In addition, results in the development of a thermally-stable, `GOES-like' scan mirror will be presented.

Seal Materials Compatible with the Electroplating Solvent Used in Constellation-X Mirrors

NASA Technical Reports Server (NTRS)

Pei, Xiong-Skiba

1999-01-01

The existing gasket seals used in electroplating of the Constellation-X mirrors are difficult to assemble, and the current seal material is hydrophobic and too thick. The combination of the above problems result in: 1) non-uniform plating; 2) defect sites such as pits on the mirror edges; 3) "bear claws" on the edges of the mandrels and mirrors causing difficulties in shell-mirror separations; and 4) leakage of the plating solution past the seals into the mandrel causing chemical etching of the mandrel interior. This paper reports the results of this summer study in searching for alternate seal materials chemically compatible with the electroplating solvent. Fifteen common elastomeric rubber seal materials made-by Parker Seals were investigated including butyl, ethylene propylene, fluorosilicone, nitrile, Viton fluorocarbon, and silicone. Test results showed that Viton fluorocarbon compounds as a group were superior to the other tested compounds for chemical compatibility with the plating bath.

Lightweight high-performance 1-4 meter class spaceborne mirrors: emerging technology for demanding spaceborne requirements

NASA Astrophysics Data System (ADS)

Hull, Tony; Hartmann, Peter; Clarkson, Andrew R.; Barentine, John M.; Jedamzik, Ralf; Westerhoff, Thomas

2010-07-01

Pending critical spaceborne requirements, including coronagraphic detection of exoplanets, require exceptionally smooth mirror surfaces, aggressive lightweighting, and low-risk cost-effective optical manufacturing methods. Simultaneous development at Schott for production of aggressively lightweighted (>90%) Zerodur® mirror blanks, and at L-3 Brashear for producing ultra-smooth surfaces on Zerodur®, will be described. New L-3 techniques for large-mirror optical fabrication include Computer Controlled Optical Surfacing (CCOS) pioneered at L-3 Tinsley, and the world's largest MRF machine in place at L-3 Brashear. We propose that exceptional mirrors for the most critical spaceborne applications can now be produced with the technologies described.

Optimizing the Performance of X-Ray Optics for MaGIXS

NASA Astrophysics Data System (ADS)

Yadlapalli, N.; Hertz, E.; Cheimets, P.

2017-12-01

The Marshall Grazing Incidence X-Ray Spectrometer (MaGIXS) is an X-ray imaging spectrometer that will observe the solar corona in the soft X-ray regime with both spatial and spectral resolution. The science goal of MaGIXS is to better understand the problem of coronal heating by measuring the temperature distribution, composition, and temporal variability of hot plasmas (>4 MK) in active regions. In order to do this, the instrument will observe the corona with a fast cadence ( 5 seconds) in wavelengths between 6-24 A with a 6" spatial resolution and a 0.1 A spectral resolution. To ensure that this instrument can achieve such a resolution, it is crucial to have exact measurements of the focal lengths of the mirrors. The mirrors will be aligned and mounted using the Centroid Detector Assembly (CDA) (a steerable laser originally developed for aligning the AXAF mirrors), a CMM Romer arm, and Hartmann aperture masks to perform the focal length measurements. We have designed metrology supports that elevate the aperture mask and mirror up to the height of the optical axis defined by the CDA of the laser, allows the aperture mask 3 translational degrees of freedom, and the allows the mirror 3 translational and 3 rotational degrees of freedom needed for alignment. The measured and verified focal lengths will then be used to carry out the alignment of the mirrors as the MaGIXS instrument is assembled for launch. MaGIXS is supported by NASA's Marshall Space Flight Center, contract number NNM15AA15C. This work is additionally supported by the NSF-REU solar physics program at SAO, grant number AGS-1560313.

Development Status of Adjustable X-Ray Optics with 0.5 Arcsecond Resolution

NASA Technical Reports Server (NTRS)

Reid, P. B.; ODell, Stephen; Elsner, Ron; Ramsey, Brian; Gubarev, Misha; Aldcroft, T.; Allured, R.; Cotroneo, V.; Johnson-Wilke, R. L.; McMuldroch, S.;

Pilot Overmyer looks over food selections and experiments with beverage

NASA Technical Reports Server (NTRS)

1982-01-01

Pilot Overmyer, using beverage container and drinking straw secured in meal tray assembly (ASSY), experiments with microgravity chararcteristics of liquid on middeck in front of forward lockers. Overmyer also looks over packages of food attached to middeck lockers in meal tray assemblies. Carry-on food warmer appears overhead and other meal tray assemblies, personal hygiene mirror assy, personal hygiene kit, and portrait of G.W.S. Abbey, JSC's Director of Flight Operations, appear on lockers.

Advanced Mirror Technology Development (AMTD) Thermal Trade Studies

NASA Technical Reports Server (NTRS)

Brooks, Thomas

2015-01-01

Advanced Mirror Technology Development (AMTD) is being done at Marshall Space Flight Center (MSFC) in preparation for the next large aperture UVOIR space observatory. A key science mission of that observatory is the detection and characterization of 'Earth-like' exoplanets. Direct exoplanet observation requires a telescope to see a planet which will be 10(exp -10) times dimmer than its host star. To accomplish this using an internal coronagraph requires a telescope with an ultra-stable wavefront error (WFE). This paper investigates parametric relationships between primary mirror physical parameters and thermal WFE stability. Candidate mirrors are designed as a mesh and placed into a thermal analysis model to determine the temperature distribution in the mirror when it is placed inside of an actively controlled cylindrical shroud at Lagrange point 2. Thermal strains resulting from the temperature distribution are found and an estimation of WFE is found to characterize the effect that thermal inputs have on the optical quality of the mirror. This process is repeated for several mirror material properties, material types, and mirror designs to determine how to design a mirror for thermal stability.

Building large telescopes in orbit using small satellites

NASA Astrophysics Data System (ADS)

Saunders, Chris; Lobb, Dan; Sweeting, Martin; Gao, Yang

2017-12-01

In many types of space mission there is a constant desire for larger and larger instrument apertures, primarily for the purposes of increased resolution or sensitivity. In the Radio Frequency domain, this is currently addressed by antennas that unfold or deploy on-orbit. However, in the optical and infrared domains, this is a significantly more challenging problem, and has up to now either been addressed by simply having large monolithic mirrors (which are fundamentally limited by the volume and mass lifting capacity of any launch vehicle) or by complex 'semi-folding' designs such as the James Webb Space Telescope. An alternative is to consider a fractionated instrument which is launched as a collection of individual smaller elements which are then assembled (or self-assemble) once in space, to form a much larger overall instrument. SSTL has been performing early concept assessment work on such systems for high resolution science observations from high orbits (potentially also for persistent surveillance of Earth). A point design of a 25 m sparse aperture (annular ring) telescope is presented. Key characteristics of 1) multiple small elements launched separately and 2) on-orbit assembly to form a larger instrument are included in the architecture. However, on-orbit assembly brings its own challenges in terms of guidance navigation and control, robotics, docking mechanisms, system control and data handling, optical alignment and stability, and many other elements. The number and type of launchers used, and the technologies and systems used heavily affect the outcome and general cost of the telescope. The paper describes one of the fractionated architecture concepts currently being studied by SSTL, including the key technologies and operational concepts that may be possible in the future.

Advanced UVOIR Mirror Technology Development (AMTD) for Very Large Space Telescopes

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Smith, W. Scott; Mosier, Gary; Abplanalp, Laura; Arnold, William

2014-01-01

ASTRO2010 Decadal stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. AMTD builds on the state of art (SOA) defined by over 30 years of monolithic & segmented ground & space-telescope mirror technology to mature six key technologies. AMTD is deliberately pursuing multiple design paths to provide the science community with op-tions to enable either large aperture monolithic or segmented mirrors with clear engineering metrics traceable to science requirements.

The Development of Stacked Core for the Fabrication of Deep Lightweight UV-Quality Space Mirrors

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Egerman, Robert; Maffett, Steven P.; Stahl, H. Philip; Eng, Ron; Effinger, Michael R.

2014-01-01

The 2010 Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. Under Science and Technology funding, NASA's Marshall Space Flight Center (MSFC) and Exelis have developed a more cost effective process to make 4m class or larger monolithic spaceflight UV quality, low areal density, thermally and dynamically stable primary mirrors. A proof of concept 0.43m mirror was completed at Exelis optically tested at 250K at MSFC which demonstrated the ability for imaging out to 2.5 microns. The parameters and test results of this concept mirror are shown. The next phase of the program includes a 1.5m subscale mirror that will be optically and dynamically tested. The scale-up process will be discussed and the technology development path to a 4m mirror system by 2018 will be outlined.

The micro-mirror technology applied to astronomy: ANIS adaptive-slit near Infrared spectrograph

NASA Astrophysics Data System (ADS)

Burgarella, Denis; Buat, Veronique; Bely, Pierre; Grange, Robert

2018-04-01

This paper, "The micro-mirror technology applied to astronomy: ANIS adaptive-slit near Infrared spectrograph," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

Development of Critical Technologies for the COSMO/SkyMed Hyperspectral Camera

DTIC Science & Technology

2000-10-01

Carbide (SiC) material (SiC or lightweighted Zerodur mirrors , carbon fiber technology. structures). - development of electronics blocks at high - High...investigation was Kcarried out to get the highest lightening factors on the Zerodur mirror substrates. Several samples of the TMA Fig. 5 - Prototypes of...implementation of state-of-the-art - manufacturing of very light mirrors with special manufacturing techniques for light components emphasis on Silicon

Analysis on influence of installation error of off-axis three-mirror optical system on imaging line-of-sight

NASA Astrophysics Data System (ADS)

Gao, Lingyu; Li, Xinghua; Guo, Qianrui; Quan, Jing; Hu, Zhengyue; Su, Zhikun; Zhang, Dong; Liu, Peilu; Li, Haopeng

2018-01-01

The internal structure of off-axis three-mirror system is commonly complex. The mirror installation error in assembly always affects the imaging line-of-sight and further degrades the image quality. Due to the complexity of the optical path in off-axis three-mirror optical system, the straightforward theoretical analysis on the variations of imaging line-of-sight is extremely difficult. In order to simplify the theoretical analysis, an equivalent single-mirror system is proposed and presented in this paper. In addition, the mathematical model of single-mirror system is established and the accurate expressions of imaging coordinate are derived. Utilizing the simulation software ZEMAX, off-axis three-mirror model and single-mirror model are both established. By adjusting the position of mirror and simulating the line-of-sight rotation of optical system, the variations of imaging coordinates are clearly observed. The final simulation results include: in off-axis three-mirror system, the varying sensitivity of the imaging coordinate to the rotation of line-of-sight is approximately 30 um/″; in single-mirror system, the varying sensitivity of the imaging coordinate to the rotation of line-of-sight is 31.5 um/″. Compared to the simulation results of the off-axis three-mirror model, the 5% relative error of single-mirror model analysis highly satisfies the requirement of equivalent analysis and also verifies its validity. This paper presents a new method to analyze the installation error of the mirror in the off-axis three-mirror system influencing on the imaging line-of-sight. Moreover, the off-axis three-mirror model is totally equivalent to the single-mirror model in theoretical analysis.

Optical integration of SPO mirror modules in the ATHENA telescope

NASA Astrophysics Data System (ADS)

Valsecchi, G.; Marioni, F.; Bianucci, G.; Zocchi, F. E.; Gallieni, D.; Parodi, G.; Ottolini, M.; Collon, M.; Civitani, M.; Pareschi, G.; Spiga, D.; Bavdaz, M.; Wille, E.

2017-08-01

ATHENA (Advanced Telescope for High-ENergy Astrophysics) is the next high-energy astrophysical mission selected by the European Space Agency for launch in 2028. The X-ray telescope consists of 1062 silicon pore optics mirror modules with a target angular resolution of 5 arcsec. Each module must be integrated on a 3 m structure with an accuracy of 1.5 arcsec for alignment and assembly. This industrial and scientific team is developing the alignment and integration process of the SPO mirror modules based on ultra-violet imaging at the 12 m focal plane. This technique promises to meet the accuracy requirement while, at the same time, allowing arbitrary integration sequence and mirror module exchangeability. Moreover, it enables monitoring the telescope point spread function during the planned 3-year integration phase.

NASA James Webb Space Telescope Engineering of the Primary Mirror Segment Assemblies (PMSA) and the Primary Mirror Backplane Support Structure (PMBSS)

NASA Technical Reports Server (NTRS)

Cohen, Lester M.

2015-01-01

The design, engineering tests of the PMSAs PMBSS show that we have a robust system that not only meets but exceeds (better than) the design requirements for these components. In the next 2 years the Telescope Observatory will be subjected to a simulated launch environment (sine vibeacoustics) and operations tests at cryogenic temperatures. Launch is schedule for the last quarter of 2018.

Numerical simulation of deformation and figure quality of precise mirror

NASA Astrophysics Data System (ADS)

Vit, Tomáš; Melich, Radek; Sandri, Paolo

2015-01-01

The presented paper shows results and a comparison of FEM numerical simulations and optical tests of the assembly of a precise Zerodur mirror with a mounting structure for space applications. It also shows how the curing of adhesive film can impact the optical surface, especially as regards deformations. Finally, the paper shows the results of the figure quality analysis, which are based on data from FEM simulation of optical surface deformations.

Large aperture freeform VIS telescope with smart alignment approach

NASA Astrophysics Data System (ADS)

Beier, Matthias; Fuhlrott, Wilko; Hartung, Johannes; Holota, Wolfgang; Gebhardt, Andreas; Risse, Stefan

2016-07-01

The development of smart alignment and integration strategies for imaging mirror systems to be used within astronomical instrumentation are especially important with regard to the increasing impact of non-rotationally symmetric optics. In the present work, well-known assembly approaches preferentially applied in the course of infrared instrumentation are transferred to visible applications and are verified during the integration of an anamorphic imaging telescope breadboard. The four mirror imaging system is based on a modular concept using mechanically fixed arrangements of each two freeform surfaces, generated by servo assisted diamond machining and corrected using Magnetorheological Finishing as a figuring and smoothing step. Surface testing include optical CGH interferometry as well as tactile profilometry and is conducted with respect to diamond milled fiducials at the mirror bodies. A strict compliance of surface referencing during all significant fabrication steps allow for an easy integration and direct measurement of the system's wave aberration after initial assembly. The achievable imaging performance, as well as influences of the tight tolerance budget and mid-spatial frequency errors, are discussed and experimentally evaluated.

Primary mirror and mount technology for the Stratospheric Observatory for Infrared Astronomy (SOFIA) telescope

NASA Technical Reports Server (NTRS)

Melugin, Ramsey K.; Chang, L. S.; Mansfield, J. A.; Howard, Steven D.

1989-01-01

Candidate technologies for a lightweight primary mirror for the SOFIA telescope are evaluated for both mirror blank fabrication and polishing. Two leading candidates for the type mirror blank are considered: the frit-bonded, structured form, and the thin meniscus form. The feasible mirror is required to be very lightweight with an areal density of approximately 100 kg/sq m, have an f/ratio near 1.0, and have surface quality that permits imaging in the visible as well as the infrared. Also considered are the results of a study conducted to assess the feasibility of designing a suitable mounting system for the primary mirror. The requirements for the mount design are given both in terms of the environmental conditions and the expected optical performance. PATRAN and NASTRAN programs are used to model mirror and mounting. The sandwich-type mirror made of ultra low expansion silica with square cells in the core, is modeled using equivalent solid elements for the core. The design study produces primary mirror surface deflections in 1g as a function of mirror elevation angles. The surface is analyzed using an optical analysis program, FRINGE, to give a prediction of the mirror optical performance. Results from this analysis are included.

Overview and Summary of Advanced UVOIR Mirror Technology Development (AMTD) Project

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2014-01-01

ASTRO2010 Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. AMTD is a multiyear effort to develop, demonstrate and mature critical technologies to TRL-6 by 2018 so that a viable flight mission can be proposed to the 2020 Decadal Review. AMTD builds on the state of art (SOA) defined by over 30 years of monolithic & segmented ground & space-telescope mirror technology to mature six key technologies: center dotLarge-Aperture, Low Areal Density, High Stiffness Mirror Substrates: Both (4 to 8 m) monolithic and (8 to 16 m) segmented telescopes require larger and stiffer mirrors. center dotSupport System: Large-aperture mirrors require large support systems to ensure that they survive launch, deploy on orbit, and maintain a stable, undistorted shape. center dotMid/High Spatial Frequency Figure Error: Very smooth mirror is critical for producing high-quality point spread function (PSF) for high contrast imaging. center dotSegment Edges: The quality of segment edges impacts PSF for high-contrast imaging applications, contributes to stray light noise, and affects total collecting aperture. center dotSegment to Segment Gap Phasing: Segment phasing is critical for producing high-quality temporally-stable PSF. center dotIntegrated Model Validation: On-orbit performance is driven by mechanical & thermal stability. Compliance cannot be 100% tested, but relies on modeling. Because we cannot predict the future, AMTD is pursuing multiple design paths to provide the science community with options to enable either large aperture monolithic or segmented mirrors with clear engineering metrics traceable to science requirements

Advanced UVOIR Mirror Technology Development (AMTD) for Very Large Space Telescopes

NASA Technical Reports Server (NTRS)

Postman, Marc; Soummer, Remi; Sivramakrishnan, Annand; Macintosh, Bruce; Guyon, Olivier; Krist, John; Stahl, H. Philip; Smith, W. Scott; Mosier, Gary; Kirk, Charles;

Automated assembly of VECSEL components

NASA Astrophysics Data System (ADS)

Brecher, C.; Pyschny, N.; Haag, S.; Mueller, T.

2013-02-01

Due to the architectural advantage of an external cavity architecture that enables the integration of additional elements into the cavity (e.g. for mode control, frequency conversion, wavelength tuning or passive mode-locking) VECSELs are a rapidly developing laser technology. Nevertheless they often have to compete with direct (edge) emitting laser diodes which can have significant cost advantages thanks to their rather simple structure and production processes. One way to compensate the economical disadvantages of VECSELs is to optimize each component in terms of quality and costs and to apply more efficient (batch) production processes. In this context, the paper presents recent process developments for the automated assembly of VECSELs using a new type of desktop assembly station with an ultra-precise micromanipulator. The core concept is to create a dedicated process development environment from which implemented processes can be transferred fluently to production equipment. By now two types of processes have been put into operation on the desktop assembly station: 1.) passive alignment of the pump optics implementing a camera-based alignment process, where the pump spot geometry and position on the semiconductor chip is analyzed and evaluated; 2.) active alignment of the end mirror based on output power measurements and optimization algorithms. In addition to the core concept and corresponding hardware and software developments, detailed results of both processes are presented explaining measurement setups as well as alignment strategies and results.

Recent Progress in Adjustable X-ray Optics for Astronomy

NASA Technical Reports Server (NTRS)

Reid, Paul B.; Allured, Ryan; Cotroneo, Vincenzo; McMuldroch, Stuart; Marquez, Vanessa; Schwartz, Daniel A.; Vikhlinin, Alexey; ODell, Stephen L.; Ramsey, Brian; Trolier-McKinstry, Susan;

Deformable mirror technologies at AOA Xinetics

NASA Astrophysics Data System (ADS)

Wirth, Allan; Cavaco, Jeffrey; Bruno, Theresa; Ezzo, Kevin M.

2013-05-01

AOA Xinetics (AOX) has been at the forefront of Deformable Mirror (DM) technology development for over two decades. In this paper the current state of that technology is reviewed and the particular strengths and weaknesses of the various DM architectures are presented. Emphasis is placed on the requirements for DMs applied to the correction of high-energy and high average power lasers. Mirror designs optimized for the correction of typical thermal lensing effects in diode pumped solid-state lasers will be detailed and their capabilities summarized. Passive thermal management techniques that allow long laser run times to be supported will also be discussed.

Optimal design of a Φ760 mm lightweight SiC mirror and the flexural mount for a space telescope

NASA Astrophysics Data System (ADS)

Li, Zongxuan; Chen, Xue; Wang, Shaoju; Jin, Guang

2017-12-01

A flexural support technique for lightweighted Primary Mirror Assembly (PMA) of a space telescope is presented in this article. The proposed three-point flexural mount based on a cartwheel flexure can maintain the surface figure of the PMA in a horizontal optical testing layout. The on-orbit surface error of the PMA causes significant degradation in image quality. On-ground optical testing cannot determine the zero-gravity figure of the PMA due to surface distortion by gravity. We unveiled the crucial fact that through a delicate mounting structure design, the surface figure can remain constant precisely without inducing distinguishable astigmatism when PMA rotates with respect to the optical axis, and the figure can be considered as the zero-gravity surface figure on the orbit. A design case is described to show the lightweight design of a SiC mirror and the optimal flexural mounting. Topology optimization and integrated opto-mechanical analysis using the finite element method are utilized in the design process. The Primary Mirror and mounting structures were fabricated and assembled. After the PMA mirror surface was polished to λ/50 RMS, optical testing in different clocking configurations was performed, respectively, through rotating the PMA by multiple angles. Test results show that the surface figure remained invariant, indicating that gravity release on the orbit will not cause an additional surface error. Vibration tests including sweep sine and random vibration were also performed to validate the mechanical design. The requirements for the mounting technique in space were qualified.

Pixelized Device Control Actuators for Large Adaptive Optics

NASA Technical Reports Server (NTRS)

Knowles, Gareth J.; Bird, Ross W.; Shea, Brian; Chen, Peter

2009-01-01

A fully integrated, compact, adaptive space optic mirror assembly has been developed, incorporating new advances in ultralight, high-performance composite mirrors. The composite mirrors use Q-switch matrix architecture-based pixelized control (PMN-PT) actuators, which achieve high-performance, large adaptive optic capability, while reducing the weight of present adaptive optic systems. The self-contained, fully assembled, 11x11x4-in. (approx.= 28x28x10-cm) unit integrates a very-high-performance 8-in. (approx.=20-cm) optic, and has 8-kHz true bandwidth. The assembled unit weighs less than 15 pounds (=6.8 kg), including all mechanical assemblies, power electronics, control electronics, drive electronics, face sheet, wiring, and cabling. It requires just three wires to be attached (power, ground, and signal) for full-function systems integration, and uses a steel-frame and epoxied electronics. The three main innovations are: 1. Ultralightweight composite optics: A new replication method for fabrication of very thin composite 20-cm-diameter laminate face sheets with good as-fabricated optical figure was developed. The approach is a new mandrel resin surface deposition onto previously fabricated thin composite laminates. 2. Matrix (regenerative) power topology: Waveform correction can be achieved across an entire face sheet at 6 kHz, even for large actuator counts. In practice, it was found to be better to develop a quadrant drive, that is, four quadrants of 169 actuators behind the face sheet. Each quadrant has a single, small, regenerative power supply driving all 169 actuators at 8 kHz in effective parallel. 3. Q-switch drive architecture: The Q-switch innovation is at the heart of the matrix architecture, and allows for a very fast current draw into a desired actuator element in 120 counts of a MHz clock without any actuator coupling.

Dynamic/Jitter Assessment of Multiple Potential HabEx Structural Designs

NASA Technical Reports Server (NTRS)

Knight, J. Brent; Stahl, H. Philip; Singleton, Andrew William; Hunt, Ronald A.; Therrell, Melissa F.; Caldwell, Mary Kathryn; Garcia, Jay Clarke

2017-01-01

The 2020 Decadal Survey in Astronomy and Astrophysics will assess candidate large missions to follow James Webb Space Telescope (JWST) and Wide Field Infrared Space Telescope (WFIRST). One candidate mission is the Habitable ExoPlanet Imaging Mission (HabEx). This presentation describes two HabEx structural designs and results from structural dynamic analyses performed to predict Primary Mirror (PM) Secondary Mirror (SM) Line of Site (LOS) stability (jitter) due to Reaction Wheel Assembly (RWA) vibrations.

W. M. Keck Observatory primary mirror segment repair project: overview and status

NASA Astrophysics Data System (ADS)

Meeks, Robert L.; Doyle, Steve; Higginson, Jamie; Hudek, John S.; Irace, William; McBride, Dennis; Pollard, Mike; Tai, Kuochou; Von Boeckmann, Tod; Wold, Leslie; Wold, Truman

2016-07-01

The W. M. Keck Observatory Segment Repair Project is repairing stress-induced fractures near the support points in the primary mirror segments. The cracks are believed to result from deficiencies in the original design and implementation of the adhesive joints connecting the Invar support components to the ZERODUR mirror. Stresses caused by temperature cycling over 20 years of service drove cracks that developed at the glass-metal interfaces. Over the last few years the extent and cause of the cracks have been studied, and new supports have been designed. Repair of the damaged glass required development of specialized tools and procedures for: (1) transport of the segments; (2) pre-repair metrology to establish the initial condition; (3) removal of support hardware assemblies; (4) removal of the original supports; (5) grinding and re-surfacing the damaged glass areas; (6) etching to remove sub-surface damage; (7) bonding new supports; (8) re-installation of support assemblies; and (9) post-repair metrology. Repair of the first segment demonstrated the new tools and processes. On-sky measurements before and after repair verified compliance with the requirements. This paper summarizes the repair process, on-sky results, and transportation system, and also provides an update on the project status and schedule for repairing all 84 mirror segments. Strategies for maintaining quality and ensuring that repairs are done consistently are also presented.

Mirror-finished superhydrophobic aluminum surfaces modified by anodic alumina nanofibers and self-assembled monolayers

NASA Astrophysics Data System (ADS)

Nakajima, Daiki; Kikuchi, Tatsuya; Natsui, Shungo; Suzuki, Ryosuke O.

2018-05-01

We demonstrate mirror-finished superhydrophobic aluminum surfaces fabricated via the formation of anodic alumina nanofibers and subsequent modification with self-assembled monolayers (SAMs). High-density anodic alumina nanofibers were formed on the aluminum surface via anodizing in a pyrophosphoric acid solution. The alumina nanofibers became tangled and bundled by further anodizing at low temperature because of their own weight, and the aluminum surface was completely covered by the long falling nanofibers. The nanofiber-covered aluminum surface exhibited superhydrophilic behavior, with a contact angle measuring less than 10°. As the nanofiber-covered aluminum surface was modified with n-alkylphosphonic acid SAMs, the water contact angle drastically shifted to superhydrophobicity, measuring more than 150°. The contact angle increased with the applied voltage during pyrophosphoric acid anodizing, the anodizing time, and the number of carbon atoms contained in the SAM molecules modified on the alumina nanofibers. By optimizing the anodizing and SAM-modification conditions, superhydrophobic behavior could be achieved with only a brief pyrophosphoric acid anodizing period of 3 min and subsequent simple immersion in SAM solutions. The superhydrophobic aluminum surface exhibited a high reflectance, measuring approximately 99% across most of the visible spectrum, similar to that of an electropolished aluminum surface. Therefore, our mirror-finished superhydrophobic aluminum surface based on anodic alumina nanofibers and SAMs can be used as a reflective mirror in various optical applications such as concentrated solar power systems.

Ultralightweight Space Deployable Primary Reflector Demonstrator

NASA Technical Reports Server (NTRS)

Montgomery, Edward E., IV; Zeiders, Glenn W.; Smith, W. Scott (Technical Monitor)

2002-01-01

A concept has been developed and analyzed and several generational prototypes built for a gossamer-class deployable truss for a mirror or reflector with many smaller precisely-figured solid elements attached will, for at least the next several decades, minimize the mass of a large primary mirror assembly while still providing the high image quality essential for planet-finding and cosmological astronomical missions. Primary mirror segments are mounted in turn on ultralightweight thermally-formed plastic panels that hold clusters of mirror segments in rigid arrays whose tip/tilt and piston would be corrected over the scale of the plastic panels by the control segments. Prototype panels developed under this program are 45 cm wide and fabricated from commercially available Kaplan sheets. A three-strut octahedral tensegrity is the basis for the overall support structure. Each fundamental is composed of two such octahedrons, rotated oppositely about a common triangular face. Adjacent modules are joined at the nodes of the upper and lower triangles to form a deployable structure that could be made arbitrarily large. A seven-module dowel-and-wire prototype has been constructed. Deployment techniques based on the use of collapsing toggled struts with diagonal tensional elements allows an assembly of tensegrities to be fully collapsed and redeployed. The prototype designs will be described and results of a test program for measuring strength and deformation will be presented.

A high fusion power gain tandem mirror

NASA Astrophysics Data System (ADS)

Fowler, T. K.; Moir, R. W.; Simonen, T. C.

2017-10-01

Utilizing advances in high field superconducting magnet technology and microwave gyrotrons we illustrate the possibility of a high power gain (Q = 10-20) tandem mirror fusion reactor. Inspired by recent Gas Dynamic Trap (GDT) achievements we employ a simple axisymmetric mirror magnet configuration. We consider both DT and cat. DD fuel options that utilize existing as well as future technology development. We identify subjects requiring further study such as hot electron physics, trapped particle modes and plasma startup.

A technology demonstrator for development of ultra-lightweight, large aperture, deployable telescope for space applications

NASA Astrophysics Data System (ADS)

Zuccaro Marchi, Alessandro; Gambicorti, Lisa; Simonetti, Francesca; Salinari, Piero; Lisi, Franco; Bursi, Alessandro; Olivier, Massimiliano; Gallieni, Daniele

2017-11-01

This work presents the latest results of new technological concepts for large aperture, lightweight telescopes using thin deployable active mirrors. The study is originally addressed to a spaceborne DIAL (Differential Absorption Lidar) at 935.5 nm for the measurement of water vapour profile in atmosphere, as an output of an ESA contract (whose preliminary results were presented at ICSO 2006). The high versatility of these concepts allows to exploit the presented technology for any project willing to consider large aperture, segmented lightweight telescopes. A possible scientific application is for Ultra High Energy Cosmic Rays detection through the fluorescence traces in atmosphere and diffused Cerenkov signals observation via a Schmidt-like spaceborne LEO telescope with large aperture, wide Field of View (FOV) and low f/#. A technology demonstrator has been manufactured and tested in order to investigate two project critical areas identified during the preliminary design: the performances of the long-stroke actuators used to implement the mirror active control and the mirror survivability to launch. In particular, this breadboard demonstrates at first that the mirror actuators are able to control with the adequate accuracy the surface shape and to recover a deployment error with their long stroke; secondly, the mirror survivability has been demonstrated using an electrostatic locking between mirror and backplane able to withstand without failure a vibration test representative of the launch environment.

Aluminum Mirror Coatings for UVOIR Telescope Optics Including the Far UV

NASA Technical Reports Server (NTRS)

Balasubramanian, Kunjithapatha; Hennessy, John; Raouf, Nasrat; Nikzad, Shouleh; Ayala, Michael; Shaklan, Stuart; Scowen, Paul; Del Hoyo, Javier; Quijada, Manuel

2015-01-01

NASA Cosmic Origins (COR) Program identified the development of high reflectivity mirror coatings for large astronomical telescopes particularly for the far ultra violet (FUV) part of the spectrum as a key technology requiring significant materials research and process development. In this paper we describe the challenges and accomplishments in producing stable high reflectance aluminum mirror coatings with conventional evaporation and advanced Atomic Layer Deposition (ALD) techniques. We present the current status of process development with reflectance of approx. 55 to 80% in the FUV achieved with little or no degradation over a year. Keywords: Large telescope optics, Aluminum mirror, far UV astrophysics, ALD, coating technology development.

Science requirements and optimization of the silicon pore optics design for the Athena mirror

NASA Astrophysics Data System (ADS)

Willingale, R.; Pareschi, G.; Christensen, F.; den Herder, J.-W.; Ferreira, D.; Jakobsen, A.; Ackermann, M.; Collon, M.; Bavdaz, M.

2014-07-01

The science requirements for the Athena X-ray mirror are to provide a collecting area of 2 m2 at 1 keV, an angular resolution of ~5 arc seconds half energy eidth (HEW) and a field of view of diameter 40-50 arc minutes. This combination of area and angular resolution over a wide field are possible because of unique features of the Silicon pore optics (SPO) technology used. Here we describe the optimization and modifications of the SPO technology required to achieve the Athena mirror specification and demonstrate how the optical design of the mirror system impacts on the scientific performance of Athena.

Modeling the Effects of Mirror Misalignment in a Ring Imaging Cherenkov Detector

NASA Astrophysics Data System (ADS)

Hitchcock, Tawanda; Harton, Austin; Garcia, Edmundo

2012-03-01

The Very High Momentum Particle Identification Detector (VHMPID) has been proposed for the ALICE experiment at the Large Hadron Collider (LHC). This detector upgrade is considered necessary to study jet-matter interaction at high energies. The VHMPID identifies charged hadrons in the 5 GeV/c to 25 GeV/c momentum range. The Cherenkov photons emitted in the VHMPID radiator are collected by spherical mirrors and focused onto a photo-detector plane forming a ring image. The radius of this ring is related to the Cherenkov angle, this information coupled with the particle momentum allows the particle identification. A major issue in the RICH detector is that environmental conditions can cause movements in mirror position. In addition, chromatic dispersion causes the refractive index to shift, altering the Cherenkov angle. We are modeling a twelve mirror RICH detector taking into account the effects of mirror misalignment and chromatic dispersion using a commercial optical software package. This will include quantifying the effects of both rotational and translational mirror misalignment for the initial assembly of the module and later on particle identification.

Federal Motor Carrier Safety Administration’s advanced system testing utilizing a data acquisition system on the highways (FAST DASH) safety technology evaluation project #3 : novel convex mirrors.

DOT National Transportation Integrated Search

2016-11-01

An independent evaluation of a set of novel prototype mirrors was conducted to determine whether the mirrors perform as well as traditional production mirrors across the basic functions of field of view (FOV), image distortion, and distance estimatio...

Electro-Formed Mirrors for Both X-Ray and Visible Astronomy

NASA Technical Reports Server (NTRS)

Ritter, J.; Smith, W. Scott; Rose, M. Frank (Technical Monitor)

2000-01-01

The Space Optics Manufacturing Technology Center of NASA's Marshall Space Flight Center is involved in the development of nickel and nickel alloy electroformed mirrors for rapid production of space-based optical systems. The current state of the process is discussed- for both cylindrical x-ray mirrors and normal incidence mirrors for visible and infrared applications.

Dynamic testbed demonstration of WFIRST coronagraph low order wavefront sensing and control (LOWFS/C)

NASA Astrophysics Data System (ADS)

Shi, Fang; Cady, Eric; Seo, Byoung-Joon; An, Xin; Balasubramanian, Kunjithapatham; Kern, Brian; Lam, Raymond; Marx, David; Moody, Dwight; Mejia Prada, Camilo; Patterson, Keith; Poberezhskiy, Ilya; Shields, Joel; Sidick, Erkin; Tang, Hong; Trauger, John; Truong, Tuan; White, Victor; Wilson, Daniel; Zhou, Hanying

2017-09-01

To maintain the required performance of WFIRST Coronagraph in a realistic space environment, a Low Order Wavefront Sensing and Control (LOWFS/C) subsystem is necessary. The LOWFS/C uses a Zernike wavefront sensor (ZWFS) with the phase shifting disk combined with the starlight rejecting occulting mask. For wavefront error corrections, WFIRST LOWFS/C uses a fast steering mirror (FSM) for line-of-sight (LoS) correction, a focusing mirror for focus drift correction, and one of the two deformable mirrors (DM) for other low order wavefront error (WFE) correction. As a part of technology development and demonstration for WFIRST Coronagraph, a dedicated Occulting Mask Coronagraph (OMC) testbed has been built and commissioned. With its configuration similar to the WFIRST flight coronagraph instrument the OMC testbed consists of two coronagraph modes, Shaped Pupil Coronagraph (SPC) and Hybrid Lyot Coronagraph (HLC), a low order wavefront sensor (LOWFS), and an optical telescope assembly (OTA) simulator which can generate realistic LoS drift and jitter as well as low order wavefront error that would be induced by the WFIRST telescope's vibration and thermal changes. In this paper, we will introduce the concept of WFIRST LOWFS/C, describe the OMC testbed, and present the testbed results of LOWFS sensor performance. We will also present our recent results from the dynamic coronagraph tests in which we have demonstrated of using LOWFS/C to maintain the coronagraph contrast with the presence of WFIRST-like line-of-sight and low order wavefront disturbances.

Lightweight Deployable Mirrors with Tensegrity Supports

NASA Technical Reports Server (NTRS)

Zeiders, Glenn W.; Bradford, Larry J.; Cleve, Richard C.

2004-01-01

The upper part of Figure 1 shows a small-scale prototype of a developmental class of lightweight, deployable structures that would support panels in precise alignments. In this case, the panel is hexagonal and supports disks that represent segments of a primary mirror of a large telescope. The lower part of Figure 1 shows a complete conceptual structure containing multiple hexagonal panels that hold mirror segments. The structures of this class are of the tensegrity type, which was invented five decades ago by artist Kenneth Snelson. A tensegrity structure consists of momentfree compression members (struts) and tension members (cables). The structures of this particular developmental class are intended primarily as means to erect large segmented primary mirrors of astronomical telescopes or large radio antennas in outer space. Other classes of tensegrity structures could also be designed for terrestrial use as towers, masts, and supports for general structural panels. An important product of the present development effort is the engineering practice of building a lightweight, deployable structure as an assembly of tensegrity modules like the one shown in Figure 2. This module comprises two octahedral tensegrity subunits that are mirror images of each other joined at their plane of mirror symmetry. In this case, the plane of mirror symmetry is both the upper plane of the lower subunit and the lower plane of the upper subunit, and is delineated by the midheight triangle in Figure 2. In the configuration assumed by the module to balance static forces under mild loading, the upper and lower planes of each sub-unit are rotated about 30 , relative to each other, about the long (vertical) axis of the structure. Larger structures can be assembled by joining multiple modules like this one at their sides or ends. When the module is compressed axially (vertically), the first-order effect is an increase in the rotation angle, but by virtue of the mirror arrangement, the net first-order rotation between the uppermost and lowermost planes is zero. The need to have zero net rotation between these planes under all loading conditions in a typical practical structure is what prompts the use of the mirror configuration. Force and moment loadings other than simple axial compression produce only second-order deformations through strains in the struts and cables.

Low-weight, low-cost, low-cycle time, replicated glass mirrors

NASA Astrophysics Data System (ADS)

Egerman, Robert; De Smitt, Steven; Strafford, David

2010-07-01

ITT has patented and continues to develop processes to fabricate low-cost borosilicate mirrors that can be used for both ground and space-based optical telescopes. Borosilicate glass is a commodity and is the material of choice for today's flat-panel televisions and monitors. Supply and demand has kept its cost low compared to mirror substrate materials typically found in telescopes. The current technology development is on the path to having the ability to deliver imaging quality optics of up to 1m (scalable to 2m) in diameter in three weeks. For those applications that can accommodate the material properties of borosilicate glasses, this technology has the potential to revolutionize ground and space-based astronomy. ITT Corporation has demonstrated finishing a planar, 0.6m borosilicate, optic to <100 nm-rms. This paper will provide an historical overview of the development in this area with an emphasis on recent technology developments to fabricate a 0.6m parabolic mirror under NASA Earth Science Technology Office (ESTO) grant #NNX09AD61G.

Novel deformable mirror design for possible wavefront correction in CO2 laser fusion system

NASA Astrophysics Data System (ADS)

Gunn, S. V.; Heinz, T. A.; Henderson, W. D.; Massie, N. A.; Viswanathan, V. K.

1980-11-01

Analysis at Los Alamos and elsewhere has resulted in the conclusion that deformable mirrors can substantially improve the optical performance of laser fusion systems, as the errors are mostly static or quasi-static with mainly low spatial frequencies across the aperture resulting in low order Seidel aberrations in the beam. A novel deformable mirror assembly (Fig. 1) has been fabricated with 19 actuators capable of surface deflection of ±20 microns. The mirror surface deflections are produced by a unique differential ball screw that acts as both a force and position actuator. The screw is driven by a stepper motor giving a surface positioning resolution of 0.025 micron. No holding voltage potential is required, and a piezoceramic element in series with each ball screw provides a ±1 micron amplitude high-frequency surface dither to aid the correction process. Mirror performance in terms of individual actuator influence function, cross-coupling, figure attainment, long-term surface stability as well as optical performance characteristics will be discussed.

A precise method for adjusting the optical system of laser sub-aperture

NASA Astrophysics Data System (ADS)

Song, Xing; Zhang, Xue-min; Yang, Jianfeng; Xue, Li

2018-02-01

In order to adapt to the requirement of modern astronomical observation and warfare, the resolution of the space telescope is needed to improve, sub-aperture stitching imaging technique is one method to improve the resolution, which could be used not only the foundation and space-based large optical systems, also used in laser transmission and microscopic imaging. A large aperture main mirror of sub-aperture stitching imaging system is composed of multiple sub-mirrors distributed according to certain laws. All sub-mirrors are off-axis mirror, so the alignment of sub-aperture stitching imaging system is more complicated than a single off-axis optical system. An alignment method based on auto-collimation imaging and interferometric imaging is introduced in this paper, by using this alignment method, a sub-aperture stitching imaging system which is composed of 12 sub-mirrors was assembled with high resolution, the beam coincidence precision is better than 0.01mm, and the system wave aberration is better than 0.05λ.

A normal incidence X-ray telescope sounding rocket payload

NASA Technical Reports Server (NTRS)

Golub, L.

1985-01-01

Progress is reported on the following major activities on the X-ray telescope: (1) complete design of the entire telescope assembly and fabrication of all front-end components was completed; (2) all rocket skin sections, including bulkheads, feedthroughs and access door, were specified; (3) fabrication, curing and delivery of the large graphite-epoxy telescope tube were completed; (4) an engineering analysis of the primary mirror vibration test was completed and a decision made to redesign the mirror attachment system to a kinematic three-point mount; (5) detail design of the camera control, payload and housekeeping electronics were completed; and (6) multilayer mirror plates with 2d spacings of 50 A and 60 A were produced.

Scatter of X-rays on polished surfaces

NASA Technical Reports Server (NTRS)

Hasinger, G.

1981-01-01

In investigating the dispersion properties of telescope mirrors used in X-ray astronomy, the slight scattering characteristics of X-ray radiation by statistically rough surfaces were examined. The mathematics and geometry of scattering theory are described. The measurement test assembly is described and results of measurements on samples of plane mirrors are given. Measurement results are evaluated. The direct beam, the convolution of the direct beam and the scattering halo, curve fitting by the method of least squares, various autocorrelation functions, results of the fitting procedure for small scattering, and deviations in the kernel of the scattering distribution are presented. A procedure for quality testing of mirror systems through diagnosis of rough surfaces is described.

Transition Metal Switchable Mirror

ScienceCinema

None

2017-12-09

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

Transition Metal Switchable Mirror

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2009-08-21

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft.

Algorithm for ion beam figuring of low-gradient mirrors.

PubMed

Jiao, Changjun; Li, Shengyi; Xie, Xuhui

2009-07-20

Ion beam figuring technology for low-gradient mirrors is discussed. Ion beam figuring is a noncontact machining technique in which a beam of high-energy ions is directed toward a target workpiece to remove material in a predetermined and controlled fashion. Owing to this noncontact mode of material removal, problems associated with tool wear and edge effects, which are common in conventional contact polishing processes, are avoided. Based on the Bayesian principle, an iterative dwell time algorithm for planar mirrors is deduced from the computer-controlled optical surfacing (CCOS) principle. With the properties of the removal function, the shaping process of low-gradient mirrors can be approximated by the linear model for planar mirrors. With these discussions, the error surface figuring technology for low-gradient mirrors with a linear path is set up. With the near-Gaussian property of the removal function, the figuring process with a spiral path can be described by the conventional linear CCOS principle, and a Bayesian-based iterative algorithm can be used to deconvolute the dwell time. Moreover, the selection criterion of the spiral parameter is given. Ion beam figuring technology with a spiral scan path based on these methods can be used to figure mirrors with non-axis-symmetrical errors. Experiments on SiC chemical vapor deposition planar and Zerodur paraboloid samples are made, and the final surface errors are all below 1/100 lambda.

WFIRST Coronagraph Technology Development Testbeds: Status and Recent Testbed Results

NASA Astrophysics Data System (ADS)

Shi, Fang; An, Xin; Balasubramanian, Kunjithapatham; cady, eric; Gordon, Brian; Greer, Frank; Kasdin, N. Jeremy; Kern, Brian; Lam, Raymond; Marx, David; Moody, Dwight; Patterson, Keith; Poberezhskiy, Ilya; mejia prada, camilo; Gersh-Range, Jessica; Eldorado Riggs, A. J.; Seo, Byoung-Joon; Shields, Joel; Sidick, Erkin; Tang, Hong; Trauger, John Terry; Truong, Tuan; White, Victor; Wilson, Daniel; Zhou, Hanying; JPL WFIRST Testbed Team, Princeton University

2018-01-01

As a part of technology development for the WFIRST coronagraph instrument (CGI), dedicated testbeds are built and commissioned at JPL. The coronagraph technology development testbeds include the Occulting Mask Coronagraph (OMC) testbed, the Shaped Pupil Coronagraph/Integral Field Spectrograph (SPC/IFS) testbed, and the Vacuum Surface Gauge (VSG) testbed. With its configuration similar to the WFIRST flight coronagraph instrument the OMC testbed consists of two coronagraph modes, Shaped Pupil Coronagraph (SPC) and Hybrid Lyot Coronagraph (HLC), a low order wavefront sensor (LOWFS), and an optical telescope assembly (OTA) simulator which can generate realistic LoS drift and jitter as well as low order wavefront error that would be induced by the WFIRST telescope’s vibration and thermal changes. The SPC/IFS testbed is a dedicated testbed to test the IFS working with a Shaped Pupil Coronagraph while the VSG testbed is for measuring and calibrating the deformable mirrors, a key component used for WFIRST CGI's wavefront control. In this poster, we will describe the testbed functions and status as well as the highlight of the latest testbed results from OMC, SPC/IFS and VSG testbeds.

Optical design for ATHENA X-ray telescope based on slumped mirror segments

NASA Astrophysics Data System (ADS)

Proserpio, Laura; Breunig, Elias; Friedrich, Peter; Winter, Anita

2014-07-01

The Hot and Energetic Universe will be the focus of future ESA missions: in late 2013 the theme was selected for the second large-class mission in the Cosmic Vision science program. Fundamental questions on how and why ordinary matter assemble into galaxies and clusters, and how black holes grow and influence their surroundings can be addressed with an advanced X-ray observatory. The currently proposed ATHENA mission presents all the potentiality to answer the outstanding questions. It is based on the heritage of XMM-Newton and on the previous studies for IXO mission. The scientific payload will require state of the art instrumentations. In particular, the baseline for the X-ray optical system, delivering a combination of large area, high angular resolution, and large field of view, is the Silicon Pore Optics technology (SPO) developed by ESA in conjunction with the Cosine Measurement Systems. The slumping technology is also under development for the manufacturing of future X-ray telescopes: for several years the Max Planck Institute for Extraterrestrial physics (MPE) has been involved in the analysis of the indirect slumping approach, which foresees the manufacturing of segmented X-ray shells by shaping thin glass foils at high temperatures over concave moulds so to avoid any contact of the optical surface with other materials during the process, preserving in this way the original X-ray quality of the glass surface. The paper presents an alternative optical design for ATHENA based on the use of thin glass mirror segments obtained through slumping.

Partial null astigmatism-compensated interferometry for a concave freeform Zernike mirror

NASA Astrophysics Data System (ADS)

Dou, Yimeng; Yuan, Qun; Gao, Zhishan; Yin, Huimin; Chen, Lu; Yao, Yanxia; Cheng, Jinlong

2018-06-01

Partial null interferometry without using any null optics is proposed to measure a concave freeform Zernike mirror. Oblique incidence on the freeform mirror is used to compensate for astigmatism as the main component in its figure, and to constrain the divergence of the test beam as well. The phase demodulated from the partial nulled interferograms is divided into low-frequency phase and high-frequency phase by Zernike polynomial fitting. The low-frequency surface figure error of the freeform mirror represented by the coefficients of Zernike polynomials is reconstructed from the low-frequency phase, applying the reverse optimization reconstruction technology in the accurate model of the interferometric system. The high-frequency surface figure error of the freeform mirror is retrieved from the high-frequency phase adopting back propagating technology, according to the updated model in which the low-frequency surface figure error has been superimposed on the sag of the freeform mirror. Simulations verified that this method is capable of testing a wide variety of astigmatism-dominated freeform mirrors due to the high dynamic range. The experimental result using our proposed method for a concave freeform Zernike mirror is consistent with the null test result employing the computer-generated hologram.

Space Science

NASA Image and Video Library

1999-04-21

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. Dr. Joe Ritter examines a replicated electro-formed nickel-alloy mirror which exemplifies the improvements in mirror fabrication techniques, with benefits such as dramtic weight reduction that have been achieved at the Marshall Space Flight Center's Space Optics Manufacturing Technology Center (SOMTC).

Secrets of the Chinese magic mirror replica

NASA Astrophysics Data System (ADS)

Mak, Se-yuen; Yip, Din-yan

2001-03-01

We examine the structure of five Chinese magic mirror replicas using a special imaging technique developed by the authors. All mirrors are found to have a two-layered structure. The reflecting surface that gives rise to a projected magic pattern on the screen is hidden under a polished half-reflecting top layer. An alternative method of making the magic mirror using ancient technology has been proposed. Finally, we suggest a simple method of reconstructing a mirror replica in the laboratory.

Advanced Mirror Technology Development (AMTD) Thermal Trade Studies

NASA Technical Reports Server (NTRS)

Brooks, Thomas; Stahl, Phil; Arnold, Bill

2015-01-01

Advanced Mirror Technology Development (AMTD) is being done at Marshall Space Flight Center (MSFC) in preparation for the next Ultraviolet, Optical, Infrared (UVOIR) space observatory. A likely science mission of that observatory is the detection and characterization of 'Earth-like' exoplanets. Direct exoplanet observation requires a telescope to see a planet that is 10-10 times dimmer than its host star. To accomplish this using an internal coronagraph requires a telescope with an ultra-stable wavefront. This paper investigates two topics: 1) parametric relationships between a primary mirror's thermal parameters and wavefront stability, and 2) optimal temperature profiles in the telescope's shroud and heater plate that minimize static wavefront error (WFE) in the primary mirror.

Simultaneous correction of large low-order and high-order aberrations with a new deformable mirror technology

NASA Astrophysics Data System (ADS)

Rooms, F.; Camet, S.; Curis, J. F.

2010-02-01

A new technology of deformable mirror will be presented. Based on magnetic actuators, these deformable mirrors feature record strokes (more than +/- 45μm of astigmatism and focus correction) with an optimized temporal behavior. Furthermore, the development has been made in order to have a large density of actuators within a small clear aperture (typically 52 actuators within a diameter of 9.0mm). We will present the key benefits of this technology for vision science: simultaneous correction of low and high order aberrations, AO-SLO image without artifacts due to the membrane vibration, optimized control, etc. Using recent papers published by Doble, Thibos and Miller, we show the performances that can be achieved by various configurations using statistical approach. The typical distribution of wavefront aberrations (both the low order aberration (LOA) and high order aberration (HOA)) have been computed and the correction applied by the mirror. We compare two configurations of deformable mirrors (52 and 97 actuators) and highlight the influence of the number of actuators on the fitting error, the photon noise error and the effective bandwidth of correction.

Optical fabrication of lightweighted 3D printed mirrors

NASA Astrophysics Data System (ADS)

Herzog, Harrison; Segal, Jacob; Smith, Jeremy; Bates, Richard; Calis, Jacob; De La Torre, Alyssa; Kim, Dae Wook; Mici, Joni; Mireles, Jorge; Stubbs, David M.; Wicker, Ryan

2015-09-01

Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) 3D printing technologies were utilized to create lightweight, optical grade mirrors out of AlSi10Mg aluminum and Ti6Al4V titanium alloys at the University of Arizona in Tucson. The mirror prototypes were polished to meet the λ/20 RMS and λ/4 P-V surface figure requirements. The intent of this project was to design topologically optimized mirrors that had a high specific stiffness and low surface displacement. Two models were designed using Altair Inspire software, and the mirrors had to endure the polishing process with the necessary stiffness to eliminate print-through. Mitigating porosity of the 3D printed mirror blanks was a challenge in the face of reconciling new printing technologies with traditional optical polishing methods. The prototypes underwent Hot Isostatic Press (HIP) and heat treatment to improve density, eliminate porosity, and relieve internal stresses. Metal 3D printing allows for nearly unlimited topological constraints on design and virtually eliminates the need for a machine shop when creating an optical quality mirror. This research can lead to an increase in mirror mounting support complexity in the manufacturing of lightweight mirrors and improve overall process efficiency. The project aspired to have many future applications of light weighted 3D printed mirrors, such as spaceflight. This paper covers the design/fab/polish/test of 3D printed mirrors, thermal/structural finite element analysis, and results.

A three-degree-of-freedom parallel manipulator for concentrated solar power towers: Modeling, simulation and design

NASA Astrophysics Data System (ADS)

Ghosal, Ashitava; Shyam, R. B. Ashith

2016-05-01

There is an increased thrust to harvest solar energy in India to meet increasing energy requirements and to minimize imported fossil fuels. In a solar power tower system, an array of tracking mirrors or heliostats are used to concentrate the incident solar energy on an elevated stationary receiver and then the thermal energy converted to electricity using a heat engine. The conventional method of tracking are the Azimuth-Elevation (Az-El) or Target-Aligned (T-A) mount. In both the cases, the mirror is rotated about two mutually perpendicular axes and is supported at the center using a pedestal which is fixed to the ground. In this paper, a three degree-of-freedom parallel manipulator, namely the 3-RPS, is proposed for tracking the sun in a solar power tower system. We present modeling, simulation and design of the 3-RPS parallel manipulator and show its advantages over conventional Az-El and T-A mounts. The 3-RPS manipulator consists of three rotary (R), three prismatic (P) and three spherical (S) joints and the mirror assembly is mounted at three points in contrast to the Az-El and T-A mounts. The kinematic equations for sun tracking are derived for the 3-RPS manipulator and from the simulations, we obtain the range of motion of the rotary, prismatic and spherical joints. Since the mirror assembly is mounted at three points, the wind load and self-weight are distributed and as a consequence, the deflections due to loading are smaller than in conventional mounts. It is shown that the weight of the supporting structure is between 15% and 65% less than that of conventional systems. Hence, even though one additional actuator is used, the larger area mirrors can be used and costs can be reduced.

GMTIFS: the adaptive optics beam steering mirror for the GMT integral-field spectrograph

NASA Astrophysics Data System (ADS)

Davies, J.; Bloxham, G.; Boz, R.; Bundy, D.; Espeland, B.; Fordham, B.; Hart, J.; Herrald, N.; Nielsen, J.; Sharp, R.; Vaccarella, A.; Vest, C.; Young, P. J.

2016-07-01

To achieve the high adaptive optics sky coverage necessary to allow the GMT Integral-Field Spectrograph (GMTIFS) to access key scientific targets, the on-instrument adaptive-optics wavefront-sensing (OIWFS) system must patrol the full 180 arcsecond diameter guide field passed to the instrument. The OIWFS uses a diffraction limited guide star as the fundamental pointing reference for the instrument. During an observation the offset between the science target and the guide star will change due to sources such as flexure, differential refraction and non-sidereal tracking rates. GMTIFS uses a beam steering mirror to set the initial offset between science target and guide star and also to correct for changes in offset. In order to reduce image motion from beam steering errors to those comparable to the AO system in the most stringent case, the beam steering mirror is set a requirement of less than 1 milliarcsecond RMS. This corresponds to a dynamic range for both actuators and sensors of better than 1/180,000. The GMTIFS beam steering mirror uses piezo-walk actuators and a combination of eddy current sensors and interferometric sensors to achieve this dynamic range and control. While the sensors are rated for cryogenic operation, the actuators are not. We report on the results of prototype testing of single actuators, with the sensors, on the bench and in a cryogenic environment. Specific failures of the system are explained and suspected reasons for them. A modified test jig is used to investigate the option of heating the actuator and we report the improved results. In addition to individual component testing, we built and tested a complete beam steering mirror assembly. Testing was conducted with a point source microscope, however controlling environmental conditions to less than 1 micron was challenging. The assembly testing investigated acquisition accuracy and if there was any un-sensed hysteresis in the system. Finally we present the revised beam steering mirror design based on the outcomes and lessons learnt from this prototyping.

Autonomous Navigation of USAF Spacecraft

DTIC Science & Technology

1983-12-01

ASSEMBLY 21.LACn. THERM AL RADEARTOR ASEML 21.5 in REFERENC BASE PLATE JELECTRONICS REFERENMODULE ASSEMBLY (4 PLACES) PORRO PRISM & BASE MIRROR -24.25...involved in active satellite-to- satellite cracking for 14 days following one day of ground tracking. Earth geopotential resonance terms are the largest...rotates a prism at 9 rps such that optical signals are injected into each telescope parallel to the reielved starlight. The angle between tne two lines

Design of the science-fold mirrors for the Gemini telescopes

NASA Astrophysics Data System (ADS)

Peschel, Thomas; Damm, Christoph; Heilemann, Wolfgang

2000-07-01

As a part of the Acquisition and Guidance Unit for the Gemini project a light-weight, 50 cm flat mirror has been designed at the Fraunhofer Institute for Applied Optics and Precision Mechanics in Jena as a subcontractor of the Carl Zeiss Jena company. A light-weight design of the mirror and its mount was essential since the total mass of the whole assembly including the positioning system was limited to 50 kg while interferometric quality of the mirror surface was required for arbitrary orientation. The overall surface error was below 54 nm r.m.s. while 27 nm was achieved in the central part. The mirror was fabricated from low-expansion glass ceramics to avoid thermally induced deformations. By milling pockets into its rear surface the mass of the mirror was reduced by 70%. The mirror is mounted cinematically via six solid-state hinges to three steel levers. The levers are connected to the mount frame at their centers via ball-and- sphere joints. This arrangement determines the position of the mirror uniquely while it allows for the thermal expansion of the mount frame. The position of the mirror as well as its tilt around an axis perpendicular to the optical one may be controlled a precision of 20 micrometers and 3 arcsec, respectively. The tilt axis is driven directly by two high- torque motors. To avoid an excessive power consumption of the motors the torque of the mirror head to be compensated for by a counterweight mechanism. The mirror may be deployed into the optical path using spindle driven linear rails.

Design, development, and testing of the DCT Cassegrain instrument support assembly

NASA Astrophysics Data System (ADS)

Bida, Thomas A.; Dunham, Edward W.; Nye, Ralph A.; Chylek, Tomas; Oliver, Richard C.

2012-09-01

The 4.3m Discovery Channel Telescope delivers an f/6.1 unvignetted 0.5° field to its RC focal plane. In order to support guiding, wavefront sensing, and instrument installations, a Cassegrain instrument support assembly has been developed which includes a facility guider and wavefront sensor package (GWAVES) and multiple interfaces for instrumentation. A 2-element, all-spherical, fused-silica corrector compensates for field curvature and astigmatism over the 0.5° FOV, while reducing ghost pupil reflections to minimal levels. Dual roving GWAVES camera probes pick off stars in the outer annulus of the corrected field, providing simultaneous guiding and wavefront sensing for telescope operations. The instrument cube supports 5 co-mounted instruments with rapid feed selection via deployable fold mirrors. The corrected beam passes through a dual filter wheel before imaging with the 6K x 6K single CCD of the Large Monolithic Imager (LMI). We describe key development strategies for the DCT Cassegrain instrument assembly and GWAVES, including construction of a prime focus test assembly with wavefront sensor utilized in fall 2011 to begin characterization of the DCT primary mirror support. We also report on 2012 on-sky test results of wavefront sensing, guiding, and imaging with the integrated Cassegrain cube.

49 CFR 591.5 - Declarations required for importation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... roads and thus is not a motor vehicle subject to the Federal motor vehicle safety, bumper, and theft... such as mirrors, wipers, or tire and rim assemblies, or minor finishing operations such as painting...

49 CFR 591.5 - Declarations required for importation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... roads and thus is not a motor vehicle subject to the Federal motor vehicle safety, bumper, and theft... such as mirrors, wipers, or tire and rim assemblies, or minor finishing operations such as painting...

49 CFR 591.5 - Declarations required for importation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... roads and thus is not a motor vehicle subject to the Federal motor vehicle safety, bumper, and theft... such as mirrors, wipers, or tire and rim assemblies, or minor finishing operations such as painting...

49 CFR 591.5 - Declarations required for importation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... roads and thus is not a motor vehicle subject to the Federal motor vehicle safety, bumper, and theft... such as mirrors, wipers, or tire and rim assemblies, or minor finishing operations such as painting...

49 CFR 591.5 - Declarations required for importation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... roads and thus is not a motor vehicle subject to the Federal motor vehicle safety, bumper, and theft... such as mirrors, wipers, or tire and rim assemblies, or minor finishing operations such as painting...

Design, Construction, and Testing of Lightweight X-ray Mirror Modules

NASA Technical Reports Server (NTRS)

McClelland, Ryan S.; Biskach, Michael P.; Chan, Kai-Wing; Espina, Rebecca A.; Hohl, Bruce R.; Matson, Elizabeth A.; Saha, Timo C.; Zhang, William W.

2013-01-01

Lightweight and high resolution optics are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The Next Generation X-ray Optics (NGXO) team at NASA GSFC is nearing mission readiness for a 10 arc-second Half Power Diameter (HPD) slumped glass mirror technology while laying the groundwork for a future 1-2 arc-second technology based on polished silicon mirrors. Technology Development Modules (TDMs) have been designed, fabricated, integrated with mirrors segments, and extensively tested to demonstrate technology readiness. Tests include X-ray performance, thermal vacuum, acoustic load, and random vibration. The thermal vacuum and acoustic load environments have proven relatively benign, while the random vibration environment has proven challenging due to large input amplification at frequencies above 500 Hz. Epoxy selection, surface preparation, and larger bond area have increased bond strength while vibration isolation has decreased vibration amplification allowing for space launch requirements to be met in the near term. The next generation of TDMs, which demonstrates a lightweight structure supporting more mirror segments, is currently being fabricated. Analysis predicts superior performance characteristics due to the use of E-60 Beryllium-Oxide Metal Matrix Composite material, with only a modest cost increase. These TDMs will be larger, lighter, stiffer, and stronger than the current generation. Preliminary steps are being taken to enable mounting and testing of 1-2 arc-second mirror segments expected to be available in the future. A Vertical X-ray Test Facility (VXTF) will minimize module gravity distortion and allow for less constrained mirror mounts, such as fully kinematic mounts. Permanent kinematic mounting into a modified TDM has been demonstrated to achieve 2 arc-second level distortion free alignment.

X ray microscope assembly and alignment support and advanced x ray microscope design and analysis

NASA Technical Reports Server (NTRS)

Shealy, David L.

1991-01-01

Considerable efforts have been devoted recently to the design, analysis, fabrication, and testing of spherical Schwarzschild microscopes for soft x ray application in microscopy and projection lithography. The spherical Schwarzschild microscope consists of two concentric spherical mirrors configured such that the third order spherical aberration and coma are zero. Since multilayers are used on the mirror substrates for x ray applications, it is desirable to have only two reflecting surfaces in a microscope. In order to reduce microscope aberrations and increase the field of view, generalized mirror surface profiles have been considered in this investigation. Based on incoherent and sine wave modulation transfer function (MTF) calculations, the object plane resolution of a microscope has been analyzed as a function of the object height and numerical aperture (NA) of the primary for several spherical Schwarzschild, conic, and aspherical head reflecting two mirror microscope configurations.

Method of bonding silver to glass and mirrors produced according to this method

DOEpatents

Pitts, J.R.; Thomas, T.M.; Czanderna, A.W.

1984-07-31

A method for adhering silver to a glass substrate for producing mirrors includes attaining a silicon enriched substrate surface by reducing the oxygen therein in a vacuum and then vacuum depositing a silver layer onto the silicon enriched surface. The silicon enrichment can be attained by electron beam bombardment, ion beam bombardment, or neutral beam bombardment. It can also be attained by depositing a metal, such as aluminum, on the substrate surface, allowing the metal to oxidize by pulling oxygen from the substrate surface, thereby leaving a silicon enriched surface, and then etching or eroding the metal oxide layer away to expose the silicon enriched surface. Ultraviolet rays can be used to maintain dangling silicon bonds on the enriched surface until covalent bonding with the silver can occur. This disclosure also includes encapsulated mirrors with diffusion layers built therein. One of these mirrors is assembled on a polymer substrate.

Method of bonding silver to glass and mirrors produced according to this method

DOEpatents

Pitts, John R.; Thomas, Terence M.; Czanderna, Alvin W.

1985-01-01

A method for adhering silver to a glass substrate for producing mirrors includes attaining a silicon enriched substrate surface by reducing the oxygen therein in a vacuum and then vacuum depositing a silver layer onto the silicon enriched surface. The silicon enrichment can be attained by electron beam bombardment, ion beam bombardment, or neutral beam bombardment. It can also be attained by depositing a metal, such as aluminum, on the substrate surface, allowing the metal to oxidize by pulling oxygen from the substrate surface, thereby leaving a silicon enriched surface, and then etching or eroding the metal oxide layer away to expose the silicon enriched surface. Ultraviolet rays can be used to maintain dangling silicon bonds on the enriched surface until covalent bonding with the silver can occur. This disclosure also includes encapsulated mirrors with diffusion layers built therein. One of these mirrors is assembled on a polymer substrate.

Cryogenic mount for mirror and piezoelectric actuator for an optical cavity.

PubMed

Oliveira, A N; Moreira, L S; Sacramento, R L; Kosulic, L; Brasil, V B; Wolff, W; Cesar, C L

2017-06-01

We present the development of a mount that accommodates a mirror and a piezoelectric actuator with emphasis on physical needs for low temperature operation. The design uses a monolithic construction with flexure features that allow it to steadily hold the mirror and the piezoelectric actuator without glue and accommodate differential thermal contraction. The mount is small and lightweight, adding little heat capacity and inertia. It provides a pre-loading of the piezoelectric actuator as well as a good thermal connection to the mirror and a thermal short across the piezoelectric actuator. The performance of the assemblies has been tested by thermally cycling from room temperature down to 3 K more than a dozen times and over one hundred times to 77 K, without showing any derating. Such mounts are proposed for the cryogenic optical enhancement cavities of the ALPHA experiment at CERN for laser spectroscopy of antihydrogen and for hydrogen spectroscopy in our laboratory at UFRJ.

An adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salmon, J.T.; Avicola, K.; Brase, J.M.

1994-04-11

We present the design and implementation of a very compact adaptive optic system that senses the return light from a sodium guide-star and controls a deformable mirror and a pointing mirror to compensate atmospheric perturbations in the wavefront. The deformable mirror has 19 electrostrictive actuators and triangular subapertures. The wavefront sensor is a Hartmann sensor with lenslets on triangular centers. The high-bandwidth steering mirror assembly incorporates an analog controller that samples the tilt with an avalanche photodiode quad cell. An {line_integral}/25 imaging leg focuses the light into a science camera that can either obtain long-exposure images or speckle data. Inmore » laboratory tests overall Strehl ratios were improved by a factor of 3 when a mylar sheet was used as an aberrator. The crossover frequency at unity gain is 30 Hz.« less

Analysis and correction for measurement error of edge sensors caused by deformation of guide flexure applied in the Thirty Meter Telescope SSA.

PubMed

Cao, Haifeng; Zhang, Jingxu; Yang, Fei; An, Qichang; Zhao, Hongchao; Guo, Peng

2018-05-01

The Thirty Meter Telescope (TMT) project will design and build a 30-m-diameter telescope for research in astronomy in visible and infrared wavelengths. The primary mirror of TMT is made up of 492 hexagonal mirror segments under active control. The highly segmented primary mirror will utilize edge sensors to align and stabilize the relative piston, tip, and tilt degrees of segments. The support system assembly (SSA) of the segmented mirror utilizes a guide flexure to decouple the axial support and lateral support, while its deformation will cause measurement error of the edge sensor. We have analyzed the theoretical relationship between the segment movement and the measurement value of the edge sensor. Further, we have proposed an error correction method with a matrix. The correction process and the simulation results of the edge sensor will be described in this paper.

Faster, Better, Cheaper: A ZERODUR® low-expansion, light-weight present path toward affordable spaceborne telescopes

NASA Astrophysics Data System (ADS)

Hull, Anthony B.; Westerhoff, Thomas

2014-06-01

For competed missions, payload costs are often the discriminate of whether or not outstanding science can be selected to fly. Optical Telescope Assemblies (OTAs) encompass a significant fraction of the payload cost, and mirror aperture and stability are usually are key to the science merit. The selection of the primary mirror approach drives architecture decisions for the rest of the OTA and even payload. We look at the ways OTA architecture is affected by the PM selection, and specifically at the benefits of selecting a low expansion material. We will also review recent advances in ZERODUR® fabrication which make this low-expansion material relevant in situations where affordable, lightweight mirrors can enable the apertures needed for science merit. Extreme Lightweight ZERODUR® Mirrors (ELZM) are available in apertures from 0.3m to over 4m. SCHOTT has recently demonstrated a relevant 1.2m ELZM substrate.

Comparing optical test methods for a lightweight primary mirror of a space-borne Cassegrain telescope

NASA Astrophysics Data System (ADS)

Lin, Wei-Cheng; Chang, Shenq-Tsong; Yu, Zong-Ru; Lin, Yu-Chuan; Ho, Cheng-Fong; Huang, Ting-Ming; Chen, Cheng-Huan

2014-09-01

A Cassegrain telescope with a 450 mm clear aperture was developed for use in a spaceborne optical remote-sensing instrument. Self-weight deformation and thermal distortion were considered: to this end, Zerodur was used to manufacture the primary mirror. The lightweight scheme adopted a hexagonal cell structure yielding a lightweight ratio of 50%. In general, optical testing on a lightweight mirror is a critical technique during both the manufacturing and assembly processes. To prevent unexpected measurement errors that cause erroneous judgment, this paper proposes a novel and reliable analytical method for optical testing, called the bench test. The proposed algorithm was used to distinguish the manufacturing form error from surface deformation caused by the mounting, supporter and gravity effects for the optical testing. The performance of the proposed bench test was compared with a conventional vertical setup for optical testing during the manufacturing process of the lightweight mirror.

Calibration results using highly aberrated images for aligning the JWST instruments to the telescope

NASA Astrophysics Data System (ADS)

Smith, Koby Z.; Acton, D. Scott; Gallagher, Ben B.; Knight, J. Scott; Dean, Bruce H.; Jurling, Alden S.; Zielinski, Thomas P.

2016-07-01

The James Webb Space Telescope (JWST) project is an international collaboration led by NASA's Goddard Space Flight Center (GSFC) in Greenbelt, MD. JWST is NASA's flagship observatory that will operate nearly a million miles away from Earth at the L2 Lagrange point. JWST's optical design is a three-mirror anastigmat with four main optical components; 1) the eighteen Primary Mirror Segment Assemblies (PMSA), 2) a single Secondary Mirror Assembly (SMA), 3) an Aft-Optics Subsystem (AOS) consisting of a Tertiary Mirror and Fine Steering Mirror, and 4) an Integrated Science Instrument Module consisting of the various instruments for JWST. JWST's optical system has been designed to accommodate a significant amount of alignment capability and risk with the PMSAs and SMA having rigid body motion available on-orbit just for alignment purposes. However, the Aft-Optics Subsystem (AOS) and Integrated Science Instrument Module (ISIM) are essentially fixed optical subsystems within JWST, and therefore the cryogenic alignment of the AOS to the ISIM is critical to the optical performance and mission success of JWST. In support of this cryogenic alignment of the AOS to ISIM, an array of fiber optic sources, known as the AOS Source Plate Assembly (ASPA), are placed near the intermediate image location of JWST (between the secondary and tertiary mirrors) during thermal vacuum ground-test operations. The AOS produces images of the ASPA fiber optic sources at the JWST focal surface location, where they are captured by the various science instruments. In this manner, the AOS provides an optical yardstick by which the instruments within ISIM can evaluate their relative positions to and the alignment of the AOS to ISIM can be quantified. However, since the ASPA is located at the intermediate image location of the JWST three-mirror anastigmat design, the images of these fiber optic sources produced by the AOS are highly aberrated with approximately 2-3μm RMS wavefront error consisting mostly of 3rd-order astigmatism and coma. This is because the elliptical tertiary mirror of the AOS is used off of its ideal foci locations without the compensating wavefront effects of the JWST primary and secondary mirrors. Therefore, the PSFs created are highly asymmetric with relatively complex structure and the centroid and encircled energy analyses traditionally used to locate images are not sufficient for ensuring the AOS to ISIM alignment. A novel approach combining phase retrieval and spatial metrology was developed to both locate the images with respect to the AOS and provide calibration information for eventual AOS to ISIM alignment verification. During final JWST OTE and ISIM (OTIS) testing, only a single thru-focus image will be collected by the instruments. Therefore, tools and processes were developed to perform single-image phase retrieval on these highly aberrated images such that any single image of the ASPA source can provide calibrated knowledge of the instruments' position relative to the AOS. This paper discusses the results of the methodology, hardware, and calibration performed to ensure that the AOS and ISIM are aligned within their respective tolerances at JWST OTIS testing.

Alignment and focus of mirrored facets of a heliosat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yellowhair, Julius E; Ho, Clifford Kuofei; Diver, Richard B

2013-11-12

Various technologies pertaining to aligning and focusing mirrored facets of a heliostat are described herein. Updating alignment and/or focus of mirrored facets is undertaken through generation of a theoretical image, wherein the theoretical image is indicative of a reflection of the target via the mirrored facets when the mirrored facets are properly aligned. This theoretical image includes reference points that are overlaid on an image of the target as reflected by the mirrored facets of the heliostat. A technician adjusts alignment/focus of a mirrored facet by causing reflected reference markings to become aligned with the reference points in the theoreticalmore » image.« less

Selecting mirror materials for high-performance optical systems

NASA Astrophysics Data System (ADS)

Parsonage, Thomas B.

1990-11-01

The properties of four candidate mirror materials--beryllium, silicon carbide, a silicon carbide/aluminum iretal-matrix carposite and aluminum--are corrpared. Because of its high specific stiffness and dirrensional stability under changing mschanical and thermal loads , beryllium is the best choice . Berjllium mirrors have been made irore cost-conpetitive by new processing technologies in which mirror blanks are isostatically pressed to near-net shape directly fran beiyllium pc1ers. Isostatic pressing also improves material properties and mskes it possible to develop mirror rraterials with superior properties.

Development of ATHENA mirror modules

NASA Astrophysics Data System (ADS)

Collon, Maximilien J.; Vacanti, Giuseppe; Barrière, Nicolas M.; Landgraf, Boris; Günther, Ramses; Vervest, Mark; van der Hoeven, Roy; Dekker, Danielle; Chatbi, Abdel; Girou, David; Sforzini, Jessica; Beijersbergen, Marco W.; Bavdaz, Marcos; Wille, Eric; Fransen, Sebastiaan; Shortt, Brian; Haneveld, Jeroen; Koelewijn, Arenda; Booysen, Karin; Wijnperle, Maurice; van Baren, Coen; Eigenraam, Alexander; Müller, Peter; Krumrey, Michael; Burwitz, Vadim; Pareschi, Giovanni; Massahi, Sonny; Christensen, Finn E.; Della Monica Ferreira, Desirée.; Valsecchi, Giuseppe; Oliver, Paul; Checquer, Ian; Ball, Kevin; Zuknik, Karl-Heinz

2017-08-01

Silicon Pore Optics (SPO), developed at cosine with the European Space Agency (ESA) and several academic and industrial partners, provides lightweight, yet stiff, high-resolution x-ray optics. This technology enables ATHENA to reach an unprecedentedly large effective area in the 0.2 - 12 keV band with an angular resolution better than 5''. After developing the technology for 50 m and 20 m focal length, this year has witnessed the first 12 m focal length mirror modules being produced. The technology development is also gaining momentum with three different radii under study: mirror modules for the inner radii (Rmin = 250 mm), outer radii (Rmax = 1500 mm) and middle radii (Rmid = 737 mm) are being developed in parallel.

A comparison of LIDT behavior of metal-dielectric mirrors in ns and ps pulse regime at 1030 nm with regard to the coating technology

NASA Astrophysics Data System (ADS)

Škoda, Václav; Vanda, Jan; Uxa, Štěpán

2017-11-01

Several sets of mirror samples with multilayer system Ta2O5/SiO2 on silver metal layer were manufactured using either PVD or IAD coating technology. Both BK7 and fused silica substrates were used for preparation of samples. Laserinduced- damage-threshold (LIDT) of metal-dielectric mirrors was tested using a laser apparatus working at 1030 nm wavelength, in ns and ps pulse length domains in S-on-1 test mode. The measured damage threshold values at 45 deg angle of incidence and P-polarization were compared for different pulse length, substrate materials and coating technology.

NASA SBIR Subtopic S2.04 "Advanced Optical Components"

NASA Technical Reports Server (NTRS)

Stahl, H. Philip

2009-01-01

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.

Discovery Channel Telescope active optics system early integration and test

NASA Astrophysics Data System (ADS)

Venetiou, Alexander J.; Bida, Thomas A.

2012-09-01

The Discovery Channel Telescope (DCT) is a 4.3-meter telescope with a thin meniscus primary mirror (M1) and a honeycomb secondary mirror (M2). The optical design is an f/6.1 Ritchey-Chrétien (RC) with an unvignetted 0.5° Field of View (FoV) at the Cassegrain focus. We describe the design, implementation and performance of the DCT active optics system (AOS). The DCT AOS maintains collimation and controls the figure of the mirror to provide seeing-limited images across the focal plane. To minimize observing overhead, rapid settling times are achieved using a combination of feed-forward and low-bandwidth feedback control using a wavefront sensing system. In 2011, we mounted a Shack-Hartmann wavefront sensor at the prime focus of M1, the Prime Focus Test Assembly (PFTA), to test the AOS with the wavefront sensor, and the feedback loop. The incoming wavefront is decomposed using Zernike polynomials, and the mirror figure is corrected with a set of bending modes. Components of the system that we tested and tuned included the Zernike to Bending Mode transformations. We also started open-loop feed-forward coefficients determination. In early 2012, the PFTA was replaced by M2, and the wavefront sensor moved to its normal location on the Cassegrain instrument assembly. We present early open loop wavefront test results with the full optical system and instrument cube, along with refinements to the overall control loop operating at RC Cassegrain focus.

Optical fiber end-facet polymer suspended-mirror devices

NASA Astrophysics Data System (ADS)

Yao, Mian; Wu, Jushuai; Zhang, A. Ping; Tam, Hwa-Yaw; Wai, P. K. A.

2017-04-01

This paper presents a novel optical fiber device based on a polymer suspended mirror on the end facet of an optical fiber. With an own-developed optical 3D micro-printing technology, SU-8 suspended-mirror devices (SMDs) were successfully fabricated on the top of a standard single-mode optical fiber. Optical reflection spectra of the fabricated SU- 8 SMDs were measured and compared with theoretical analysis. The proposed technology paves a way towards 3D microengineering of the small end-facet of optical fibers to develop novel fiber-optic sensors.

Transition Metal Switchable Mirror

ScienceCinema

None

2017-12-29

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

Rapid Fabrication of Lightweight SiC Optics using Reactive Atom Plasma (RAP) Processing

NASA Technical Reports Server (NTRS)

Fiske, Peter S.

2006-01-01

Reactive Atom Plasma (RAP) processing is a non-contact, plasma-based processing technology that can be used to generate damage-free optical surfaces. We have developed tools and processes using RAP that allow us to shape extremely lightweight mirror Surfaces made from extremely hard-to-machine materials (e.g. SiC). We will describe our latest results using RAP in combination with other technologies to produce finished lightweight SiC mirrors and also discuss applications for RAP in the rapid fabrication of mirror segments for reflective and grazing incidence telescopes.

Research Technology

NASA Image and Video Library

1998-09-16

A team of engineers at Marshall Space Flight Center (MSFC) has designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket that produces lower thrust but has better thrust efficiency than the chemical combustion engines. This segmented array of mirrors is the solar concentrator test stand at MSFC for firing the thermal propulsion engines. The 144 mirrors are combined to form an 18-foot diameter array concentrator. The mirror segments are aluminum hexagons that have the reflective surface cut into it by a diamond turning machine, which is developed by MSFC Space Optics Manufacturing Technology Center.

Transition Metal Switchable Mirror

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2009-08-21

The switchable-mirrors technology was developed by Tom Richardson and Jonathan Slack of Berkeley Lab's Environmental Energy Technologies Division. By using transition metals rather than the rare earth metals used in the first metal-hydride switchable mirrors, Richardson and Slack were able to lower the cost and simplify the manufacturing process. Energy performance is improved as well, because the new windows can reflect or transmit both visible and infrared light. Besides windows for offices and homes, possible applications include automobile sunroofs, signs and displays, aircraft windows, and spacecraft. More information at: http://windows.lbl.gov/materials/chromogenics/default.htm

Computerised mirror therapy with Augmented Reflection Technology for early stroke rehabilitation: clinical feasibility and integration as an adjunct therapy.

PubMed

Hoermann, Simon; Ferreira Dos Santos, Luara; Morkisch, Nadine; Jettkowski, Katrin; Sillis, Moran; Devan, Hemakumar; Kanagasabai, Parimala S; Schmidt, Henning; Krüger, Jörg; Dohle, Christian; Regenbrecht, Holger; Hale, Leigh; Cutfield, Nicholas J

2017-07-01

New rehabilitation strategies for post-stroke upper limb rehabilitation employing visual stimulation show promising results, however, cost-efficient and clinically feasible ways to provide these interventions are still lacking. An integral step is to translate recent technological advances, such as in virtual and augmented reality, into therapeutic practice to improve outcomes for patients. This requires research on the adaptation of the technology for clinical use as well as on the appropriate guidelines and protocols for sustainable integration into therapeutic routines. Here, we present and evaluate a novel and affordable augmented reality system (Augmented Reflection Technology, ART) in combination with a validated mirror therapy protocol for upper limb rehabilitation after stroke. We evaluated components of the therapeutic intervention, from the patients' and the therapists' points of view in a clinical feasibility study at a rehabilitation centre. We also assessed the integration of ART as an adjunct therapy for the clinical rehabilitation of subacute patients at two different hospitals. The results showed that the combination and application of the Berlin Protocol for Mirror Therapy together with ART was feasible for clinical use. This combination was integrated into the therapeutic plan of subacute stroke patients at the two clinical locations where the second part of this research was conducted. Our findings pave the way for using technology to provide mirror therapy in clinical settings and show potential for the more effective use of inpatient time and enhanced recoveries for patients. Implications for Rehabilitation Computerised Mirror Therapy is feasible for clinical use Augmented Reflection Technology can be integrated as an adjunctive therapeutic intervention for subacute stroke patients in an inpatient setting Virtual Rehabilitation devices such as Augmented Reflection Technology have considerable potential to enhance stroke rehabilitation.

Precision Linear Actuators for the Spherical Primary Optical Telescope Demonstration Mirror

NASA Technical Reports Server (NTRS)

Budinoff, Jason; Pfenning, David

2006-01-01

The Spherical Primary Optical Telescope (SPOT) is an ongoing research effort at Goddard Space Flight Center developing wavefront sensing and control architectures for future space telescopes. The 03.5-m SPOT telescope primary mirror is comprise9 of six 0.86-m hexagonal mirror segments arranged in a single ring, with the central segment missing. The mirror segments are designed for laboratory use and are not lightweighted to reduce cost. Each primary mirror segment is actuated and has tip, tilt, and piston rigid-body motions. Additionally, the radius of curvature of each mirror segment may be varied mechanically. To provide these degrees of freedom, the SPOT mirror segment assembly requires linear actuators capable of

Analysis and design of segment control system in segmented primary mirror

NASA Astrophysics Data System (ADS)

Yu, Wenhao; Li, Bin; Chen, Mo; Xian, Hao

2017-10-01

Segmented primary mirror will be adopted widely in giant telescopes in future, such as TMT, E-ELT and GMT. High-performance control technology of the segmented primary mirror is one of the difficult technologies for telescopes using segmented primary mirror. The control of each segment is the basis of control system in segmented mirror. Correcting the tilt and tip of single segment is the main work of this paper which is divided into two parts. Firstly, harmonic response done in finite element model of single segment matches the Bode diagram of a two-order system whose natural frequency is 45 hertz and damping ratio is 0.005. Secondly, a control system model is established, and speed feedback is introduced in control loop to suppress resonance point gain and increase the open-loop bandwidth, up to 30Hz or even higher. Corresponding controller is designed based on the control system model described above.

Space Science

NASA Image and Video Library

1999-04-20

NASA's Space Optics Manufacturing Technology Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century, including the long-term goal of imaging Earth-like planets in distant solar systems. A segmented array of mirrors was designed by the Space Optics Manufacturing Technology Center for the solar concentrator test stand at the Marshall Space Flight Center (MSFC) for powering solar thermal propulsion engines. Each hexagon mirror has a spherical surface to approximate a parabolic concentrator when combined into the entire 18-foot diameter array. The aluminum mirrors were polished with a diamond turning machine that creates a glass-like reflective finish on metal. The precision fabrication machinery at the Space Optics Manufacturing Technology Center at MSFC can polish specialized optical elements to a world class quality of smoothness. This image shows optics physicist, Vince Huegele, examining one of the 144-segment hexagonal mirrors of the 18-foot diameter array at the MSFC solar concentrator test stand.

Space Science

NASA Image and Video Library

1999-04-20

NASA's Space Optics Manufacturing Technology Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century, including the long-term goal of imaging Earth-like planets in distant solar systems. A segmented array of mirrors was designed by the Space Optics Manufacturing Technology Center for solar the concentrator test stand at the Marshall Space Flight Center (MSFC) for powering solar thermal propulsion engines. Each hexagon mirror has a spherical surface to approximate a parabolic concentrator when combined into the entire 18-foot diameter array. The aluminum mirrors were polished with a diamond turning machine, that creates a glass-like reflective finish on metal. The precision fabrication machinery at the Space Optics Manufacturing Technology Center at MSFC can polish specialized optical elements to a world class quality of smoothness. This image shows optics physicist, Vince Huegele, examining one of the 144-segment hexagonal mirrors of the 18-foot diameter array at the MSFC solar concentrator test stand.

First results from the TOPSAT camera

NASA Astrophysics Data System (ADS)

Greenway, Paul; Tosh, Ian; Morris, Nigel; Burton, Gary; Cawley, Steve

2017-11-01

The TopSat camera is a low cost remote sensing imager capable of producing 2.5 metre resolution panchromatic imagery, funded by the British National Space Centre's Mosaic programme. The instrument was designed and assembled at the Space Science & Technology Department of the CCLRC's Rutherford Appleton Laboratory (RAL) in the UK, and was launched on the 27th October 2005 from Plesetsk Cosmodrome in Northern Russia on a Kosmos-3M. The camera utilises an off-axis three mirror system, which has the advantages of excellent image quality over a wide field of view, combined with a compactness that makes its overall dimensions smaller than its focal length. Keeping the costs to a minimum has been a major design driver in the development of this camera. The camera is part of the TopSat mission, which is a collaboration between four UK organisations; QinetiQ, Surrey Satellite Technology Ltd (SSTL), RAL and Infoterra. Its objective is to demonstrate provision of rapid response high resolution imagery to fixed and mobile ground stations using a low cost minisatellite. The paper "Development of the TopSat Camera" presented by RAL at the 5th ICSO in 2004 described the opto-mechanical design, assembly, alignment and environmental test methods implemented. Now that the spacecraft is in orbit and successfully acquiring images, this paper presents the first results from the camera and makes an initial assessment of the camera's in-orbit performance.

Neutron star Interior Composition Explorer (NICER)

NASA Image and Video Library

2017-12-08

NICER team members Takashi Okajima, Yang Soong, and Steven Kenyon apply epoxy to the X-ray concentrator mounts after alignment. The epoxy holds the optics assemblies fixed in position through the vibrations experienced during launch to the International Space Station. The payload’s 56 mirror assemblies concentrate X-rays onto silicon detectors to gather data that will probe the interior makeup of neutron stars, including those that appear to flash regularly, called pulsars. The Neutron star Interior Composition Explorer (NICER) is a NASA Explorer Mission of Opportunity dedicated to studying the extraordinary environments — strong gravity, ultra-dense matter, and the most powerful magnetic fields in the universe — embodied by neutron stars. An attached payload aboard the International Space Station, NICER will deploy an instrument with unique capabilities for timing and spectroscopy of fast X-ray brightness fluctuations. The embedded Station Explorer for X-ray Timing and Navigation Technology demonstration (SEXTANT) will use NICER data to validate, for the first time in space, technology that exploits pulsars as natural navigation beacons. Credit: NASA/Goddard/ Keith Gendreau NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Orbital Verification of the CXO High-Resolution Mirror Assembly Alignment and Vignetting

NASA Technical Reports Server (NTRS)

Gaetz, T. J.; Jerius, D.; Edgar, R. J.; VanSpeybroeck, L. P.; Schwartz, D. A.; Markevitch, M.; Schulz, N. S.

2000-01-01

Prior to launch, the High Resolution Mirror Assembly (HRMA) of the Chandra X-ray Observatory underwent extensive ground testing at the X-ray Calibration Facility (XRCF) at the Marshall Space Flight Center in Huntsville. Observations made during the post-launch Orbital Activation and Calibration period, allow the on-orbit condition of the X-ray optics to be assessed. Based on these ground-based and on-orbit data, we examine the alignment of the x-ray optics based on the PSF, and the boresight and alignment of the optical axis alignment relative to the detectors. We examine the vignetting and the single reflection ghost suppression properties of the telescope. Slight imperfections in alignment lead to a small azimuthal dependence of the off-axis area; the morphology of off-axis images also shows an additional small azimuthal dependence varying as 1/2 the off-axis azimuth angle.

AXAF-1 high-resolution mirror assembly image model and comparison with x-ray ground-test image

NASA Astrophysics Data System (ADS)

Zissa, David E.

1999-09-01

The completed High Resolution Mirror Assembly (HRMA) of the Advanced X-ray Astrophysics Facility - Imaging (AXAF-I) was tested at the X-ray Calibration Facility (XRCF) at the NASA- Marshall Space Flight Center (MSFC) in 1997. The MSFC image model was developed during the development of AXAF-I. The MSFC model is a detailed ray-trace model of the as-built HRMA optics and the XRCF teste conditions. The image encircled-energy distributions from the model are found to general agree well with XRCF test data nd the preliminary Smithsonian Astrophysical Observatory (SAO) model. MSFC model effective-area result generally agree with those of the preliminary SAO model. Preliminary model effective-area results were reported by SAO to be approximately 5-13 percent above initial XRCF test results. The XRCF test conditions are removed from the MSFC ray-trace model to derive an on-orbit prediction of the HRMA image.

On sky testing of the SOFIA telescope in preparation for the first science observations

NASA Astrophysics Data System (ADS)

Harms, Franziska; Wolf, Jürgen; Waddell, Patrick; Dunham, Edward; Reinacher, Andreas; Lampater, Ulrich; Jakob, Holger; Bjarke, Lisa; Adams, Sybil; Grashuis, Randy; Meyer, Allan; Bower, Kenneth; Schweikhard, Keith; Keilig, Thomas

2009-08-01

SOFIA, the Stratospheric Observatory for Infrared Astronomy, is an airborne observatory that will study the universe in the infrared spectrum. A Boeing 747-SP aircraft will carry a 2.5 m telescope designed to make sensitive infrared measurements of a wide range of astronomical objects. In 2008, SOFIA's primary mirror was demounted and coated for the first time. After reintegration into the telescope assembly in the aircraft, the alignment of the telescope optics was repeated and successive functional and performance testing of the fully integrated telescope assembly was completed on the ground. The High-speed Imaging Photometer for Occultations (HIPO) was used as a test instrument for aligning the optics and calibrating and tuning the telescope's pointing and control system in preparation for the first science observations in flight. In this paper, we describe the mirror coating process, the subsequent telescope testing campaigns and present the results.

AXAF VETA-I mirror ring focus measurements

NASA Technical Reports Server (NTRS)

Tananbaum, H. D.; Zhao, P.

1994-01-01

The AXAF VETA-I mirror ring focus measurements were made with an HRI (microchannel plate) X-ray detector. The ring focus is a sharply focused ring formed by X-rays before they reach the VEAT-I focal plane. It is caused by spherical aberrations due to the finite source distance and the despace in the VETA-I test. The ring focus test reveals some aspects fo the test system distortions and the mirror surface figure which are difficult or impossible to detect at the focal plane. The test results show periodic modulations of the ring radius and width which could be caused by gravity, thermal, and/or epoxy shrinkage distortions. The strongest component of the modulation had a 12-fold symmetry, because these distortions were exerted on the mirror through 12 flexures of the VETA-I mount. Ring focus models were developed to simulate the ring image. The models were compared with the data to understand the test system distortions and the mirror glass imperfection. Further studies will be done to complete this work. The ring focus measurement is a very powerful test. We expect that a similar test for the finally assembled mirror of AXAD-I will be highly valuable.

Alignment of the Korsch type off-axis 3 mirror optical system using sensitivity table method

NASA Astrophysics Data System (ADS)

Lee, Kyoungmuk; Kim, Youngsoo; Hong, Jinsuk; Kim, Sug-Whan; Lee, Haeng-Bok; Choi, Se-Chol

2018-05-01

The optical system of the entire mechanical and optical components consist of all silicon carbide (SiC) is designed, manufactured and aligned. The Korsch type Cassegrain optical system has 3-mirrors, the primary mirror (M1), the secondary mirror (M2), the folding mirror (FM) and the tertiary mirror (M3). To assemble the M3 and the FM to the rear side of the M1 bench, the optical axis of the M3 is 65.56 mm off from the physical center. Due to the limitation of the mass budget, the M3 is truncated excluding its optical axis. The M2 was assigned to the coma compensator and the M3 the astigmatism respectively as per the result of the sensitivity analysis. Despite of the difficulty of placing these optical components in their initial position within the mechanical tolerance, the initial wave front error (WFE) performance is as large as 171.4 nm RMS. After the initial alignment, the sensitivity table method is used to reach the goal of WFE 63.3 nm RMS in all fields. We finished the alignment with the final WFE performance in all fields are as large as 55.18 nm RMS.

Novel 3D micromirror for miniature optical bio-robe SiOB assembly

NASA Astrophysics Data System (ADS)

Singh, Janak; Xu, Yingshun; Premachandran, C. S.; Jason, Teo Hui Siang; Chen, Nanguang

2008-02-01

This article presents design and development of a novel 3D micromirror for large deflection scanning application in invivo optical coherence tomography (OCT) bio-imaging probe. Overall mirror chip size is critical to reduce the diameter of the probe; however, mirror plate itself should not be less than 500 μm as smaller size means reducing the amount of light collected after scattering for OCT imaging. In this study, mirror chip sizes of 1 × 1 mm2 and 1.5 × 1.5 mm2 were developed with respectively 400 and 500 micrometer diameter mirror plates. The design includes electro thermal excitation mechanism in the same plane as mirror plate to achieve 3D free space scanning. Larger deflection requires longer actuators, which usually increase the overall size of the chip. To accommodate longer actuators and keep overall chip size same curved beam actuators are designed and integrated for micromirror scanning. Typical length of the actuators was 800 micrometer, which provided up to 17 degrees deflection. Deep reactive ion etching (DRIE) process module was used extensively to etch high aspect ratio structures and keep the total mirror chip size small.

Slumped glass option for making the XEUS mirrors: preliminary design and ongoing developments

NASA Astrophysics Data System (ADS)

Ghigo, M.; Canestrari, R.; Proserpio, L.; Dell'Orto, E.; Basso, S.; Citterio, O.; Pareschi, G.; Parodi, Giancarlo

2008-07-01

The XEUS mission (X-ray Evolving-Universe Spectroscopy Mission) of ESA, in the present configuration has a mirror collecting area in the order of 5-6 m2 @ 1 keV, 2 m2 @ 7 keV and 1 m2 @ 10 keV. These large collecting areas could be obtained with a mirror assembly composed of a large number of high quality segments each being able to deliver the angular resolution requested by the mission or better. The XEUS telescope will fit in the fairing of an Ariane 5 ECA launcher and hence its diameter is presently of about 4.5 m. The request in terms of angular resolution of the telescope has been set to 5 arcsec with a goal of 2 arcsec. Due to the large size of the optics it is impossible to create closed shells like those used for XMM or Chandra and hence it will be necessary to assemble a large number of segments (for example of ~0.6 m x ~0.3 m size) to recreate the mirror shells. These segments will form a module, an optical sub-unit of the telescope. The modules will be assembled to form the whole mirror system. As for all the space missions, the limits imposed on the payload mass budget by the launcher is the main driver that force the use of very lightweight optics and this request is of course very challenging. For example, the current design for XEUS foresees a geometric-area/mass ratio better than about 30 cm2/kg. In this article is illustrated a possible approach for the realization of large size and lightweight X-ray mirrors that derive from an experience gained from a previous work made in INAF-OAB on the thermal slumping of thin glass optics. The process foresees the use of a mould having a good optical figure but opposite shape respect to the segment to be slumped. On the mould is placed an initially flat glass sheet. With a suitable thermal cycle the glass sheet is conformed to the mould shape. Once tested for acceptance the glass sheet it is then integrated into a module by means of a robotic arm having a feedback system to confirm the correct alignment. A study on different optical geometries using the classical Wolter I and Kirkpatrick-Baez configurations has been also performed to investigate the theoretical performances obtainable with optics made using very thin glass shells.

Engineering the Future: Cell 6

NASA Technical Reports Server (NTRS)

Stahl, P. H.

2010-01-01

This slide presentation reviews the development of the James Webb Space Telescope (JWST), explaining the development using a systems engineering methodology. Included are slides showing the organizational chart, the JWST Science Goals, the size of the primary mirror, and full scale mockups of the JSWT. Also included is a review of the JWST Optical Telescope Requirements, a review of the preliminary design and analysis, the technology development required to create the JWST, with particular interest in the specific mirror technology that was required, and views of the mirror manufacturing process. Several slides review the process of verification and validation by testing and analysis, including a diagram of the Cryogenic Test Facility at Marshall, and views of the primary mirror while being tested in the cryogenic facility.

Technology Development for Nickel X-Ray Optics Enhancement

NASA Technical Reports Server (NTRS)

Bubarev, Mikhail; Ramsey, Brian; Engelhaupt, Darell

2008-01-01

We are developing grazing-incidence x-ray optics for high-energy astrophysics using the electroform-nickel replication process. In this process, mirror shells are fabricated by replication off super-polished cylindrical mandrels. The mirrors fabricated using this process have a demonstrated optical performance at the level of 11-12 arc seconds resolution (HPD) for 30 keV x rays. Future missions demand ever higher angular resolutions and this places stringent requirements on the quality of the mandrels, the precision of the metrology, and the mounting and alignment of the mirror shells in their housings. A progress report on recent technology developments in all these areas will be presented along with a discussion on possible post fabrication, in-situ improvement of the x-ray mirrors quality.

Space Science

NASA Image and Video Library

1999-04-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. Image shows Dr. Alan Shapiro cleaning mirror mandrel to be applied with highly reflective and high-density coating in the Large Aperture Coating Chamber, MFSC Space Optics Manufacturing Technology Center (SOMTC).

Design and simulation of the surface shape control system for membrane mirror

NASA Astrophysics Data System (ADS)

Zhang, Gengsheng; Tang, Minxue

2009-11-01

The surface shape control is one of the key technologies for the manufacture of membrane mirror. This paper presents a design of membrane mirror's surface shape control system on the basis of fuzzy logic control. The system contains such function modules as surface shape design, surface shape control, surface shape analysis, and etc. The system functions are realized by using hybrid programming technology of Visual C# and MATLAB. The finite element method is adopted to simulate the surface shape control of membrane mirror. The finite element analysis model is established through ANSYS Parametric Design Language (APDL). ANSYS software kernel is called by the system in background running mode when doing the simulation. The controller is designed by means of controlling the sag of the mirror's central crosssection. The surface shape of the membrane mirror and its optical aberration are obtained by applying Zernike polynomial fitting. The analysis of surface shape control and the simulation of disturbance response are performed for a membrane mirror with 300mm aperture and F/2.7. The result of the simulation shows that by using the designed control system, the RMS wavefront error of the mirror can reach to 142λ (λ=632.8nm), which is consistent to the surface accuracy of the membrane mirror obtained by the large deformation theory of membrane under the same condition.

Highly light-weighted ZERODUR mirror and fixation for cryogenic applications

NASA Astrophysics Data System (ADS)

Behar-Lafenetre, Stephanie; Lasic, Thierry; Viale, Roger; Ruch, Eric

2017-11-01

Space telescopes require large primary mirrors within a demanding thermal environment: observatories at L2 orbit provide a stable environment with a drawback of very low temperature. Besides, it is necessary to limit as far as possible the mirrors mass while withstanding launch loads and keeping image quality within a cryogenic environment. ZERODUR is a well-known material extensively used for large telescope. Alcatel Alenia Space and Sagem/REOSC have combined their respective skills to go further in the lightweighting ratio of large mirror (36 kg/m2 on 1.5 m2) through a detailed design, performance assessment and technology demonstration with breadboards. Beyond on a large mirror detailed design supported by analysis, a ZERODUR mock-up has been manufacturing by Sagem/REOSC to demonstrate the achievability of the demanding parameters offering this high lightweighting ratio. Through the ISO experience on mirror attachments, a detailed design of the mirror fixation has been done as well. A full size mock-up has been manufactured and successfully tested under thermal cycling and static loading. Eventually, the ZERODUR stability behavior within this large temperature range has been verified through thermal cycling and image quality cryotest on a flat mirror breadboard. These developments demonstrate that ZERODUR is a good candidate for large space cryogenic mirrors offering outstanding optical performances associated to matured and proven technology and manufacturing process.

A Piezoelectric Unimorph Deformable Mirror Concept by Wafer Transfer for Ultra Large Space Telescopes

NASA Technical Reports Server (NTRS)

Yang, Eui-Hyeok; Shcheglov, Kirill

2002-01-01

Future concepts of ultra large space telescopes include segmented silicon mirrors and inflatable polymer mirrors. Primary mirrors for these systems cannot meet optical surface figure requirements and are likely to generate over several microns of wavefront errors. In order to correct for these large wavefront errors, high stroke optical quality deformable mirrors are required. JPL has recently developed a new technology for transferring an entire wafer-level mirror membrane from one substrate to another. A thin membrane, 100 mm in diameter, has been successfully transferred without using adhesives or polymers. The measured peak-to-valley surface error of a transferred and patterned membrane (1 mm x 1 mm x 0.016 mm) is only 9 nm. The mirror element actuation principle is based on a piezoelectric unimorph. A voltage applied to the piezoelectric layer induces stress in the longitudinal direction causing the film to deform and pull on the mirror connected to it. The advantage of this approach is that the small longitudinal strains obtainable from a piezoelectric material at modest voltages are thus translated into large vertical displacements. Modeling is performed for a unimorph membrane consisting of clamped rectangular membrane with a PZT layer with variable dimensions. The membrane transfer technology is combined with the piezoelectric bimorph actuator concept to constitute a compact deformable mirror device with a large stroke actuation of a continuous mirror membrane, resulting in a compact A0 systems for use in ultra large space telescopes.

Static and dynamic micro deformable mirror characterization by phase-shifting and time-averaged interferometry

NASA Astrophysics Data System (ADS)

Liotard, Arnaud; Zamkotsian, Frédéric

2017-11-01

The micro-opto-electro-mechanical systems (MOEMS), based on mature technologies of micro-electronics, are essential in the design of future astronomical instruments. One of these key-components is the microdeformable mirror for wave-front correction. Very challenging topics like search of exo-planets could greatly benefit from this technology. Design, realization and characterization of micro-Deformable Mirrors are under way at Laboratoire d'Astrophysique de Marseille (LAM) in collaboration with Laboratoire d'Analyse et d'Architecture des Systèmes (LAAS). In order to measure the surface shape and the deformation parameters during operation of these devices, a high-resolution Twyman-Green interferometer has been developed. Measurements have been done on a tiltable micro-mirror (170*100μm2) designed by LAM-LAAS and realized by an American foundry, and also on an OKO deformable mirror (15mm diameter). Static characterization is made by phase shifting interferometry and dynamic measurements have been made by quantitative time-averaged interferometry. The OKO mirror has an actuator stroke of 370+/-10nm for 150V applied and its resonant frequency is 1170+/-50 Hz, and the tiltable mirror has a rotation cut-off frequency of 31+/-3 kHz.

Cryogenic Test Results of Hextek Mirror

NASA Technical Reports Server (NTRS)

Hadaway, James; Stahl, H. Philip; Eng, Ron; Hogue, William

2004-01-01

A 250 mm diameter lightweight borosilicate mirror has been interferometrically tested from room-temperature down to 30 K at the X-Ray Calibration Facility (XRCF) at Marshall Space Flight Center (MSFC). The minor blank was manufactured by Hextek Corporation using a high-temperature gas fusion process and was then polished at MSFC. It is a sandwich-type mirror consisting of a thin face-sheet (approx.1.5 mm thick), a core structure (20 mm thick, approx.43 mm diameter cells, & 0.5-1.2 mm thick walls), and a thin back-sheet (3 mm thick). The mirror has a 2500 mm spherical radius-of- curvature @/lo). The areal density is 14 kg/sq m. The mirror was tested in the 1 m x 2 m chamber using an Instantaneous Phase Interferometer (PI) from ADE Phase Shift Technologies. The mirror was tested twice. The first test measured the change in surface figure from ambient to 30 K and the repeatability of the change. An attempt was then made by QED Technologies to cryo-figure the mirror using magnetorheological finishing. The second test measured the effectiveness of the cryo- figuring. This paper will describe the test goals, the test instrumentation, and the test results for these cryogenic tests.

The 11th Aerospace Mechanisms Symposium

NASA Technical Reports Server (NTRS)

1977-01-01

Various mechanisms in aerospace engineering were presented at this conference. Specifications, design, and use of spacecraft and missile components are discussed, such as tail assemblies, radiometers, magnetormeters, pins, reaction wheels, ball bearings, actuators, mirrors, nutation dampers, airfoils, solar arrays, etc.

Mounting and Alignment of Full-Shell Replicated X-Ray Optics

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Arnold, William; Kester, Thomas; Ramsey, Brian; Smithers, Martin

2007-01-01

We are developing grazing-incidence x-ray optics for astronomy. The optics are full-cylinder mirror shells fabricated using electroformed-nickel replication off super-polished mandrels. For space-based applications where weight is at a premium, very-thin-walled, light-weight mirrors are required. Such shells have been fabricated at MSFC with greater than 15 arcsec resolution. The challenge, however, is to preserve this resolution during mounting and assembly. We present here a status report on a mounting and alignment system currently under development at Marshall Space Flight Center to meet this challenge.

JWST Pathfinder Telescope Risk Reduction Cryo Test Program

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Scorse, Thomas R.; Spina, John A.; Noel, Darin M.; Havey, Keith A., Jr.; Huguet, Jesse A.; Whitman, Tony L.; Wells, Conrad; Walker, Chanda B.; Lunt, Sharon;

Cutting assembly

DOEpatents

Racki, Daniel J.; Swenson, Clark E.; Bencloski, William A.; Wineman, Arthur L.

1984-01-01

A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

X-Ray Testing Constellation-X Optics at MSFC's 100-m Facility

NASA Technical Reports Server (NTRS)

O'Dell, Stephen; Baker, Markus; Content, David; Freeman, Mark; Glenn, Paul; Gubarev, Mikhail; Hair, Jason; Jones, William; Joy, Marshall

2003-01-01

In addition to the 530-m-long X-Ray Calibration Facility (XRCF), NASA's Marshall Space Flight Center (MSFC) operates a 104-m-long (source-to-detector) X-ray-test facility. Originally developed and still occasionally used for stray-light testing of visible-fight optical systems, the so-called "Stray-Light Facility" now serves primarily as a convenient and inexpensive facility for performance evaluation and calibration of X-ray optics and detectors. The facility can accommodate X-ray optics up to about 1-m diameter and 12-m focal length. Currently available electron-impact sources at the facility span the approximate energy range 0.2 to 100 keV, thus supporting testing of soft- and hard-X-ray optics and detectors. Available MSFC detectors are a front-illuminated CCD (charge-coupled device) and a scanning CZT (cadmium--zinc--telluride) detector, with low-energy cut-offs of about 0.8 and 3 keV, respectively. In order to test developmental optics for the Constellation-X Project, led by NASA's Goddard Space Flight Center (GSFC), MSFC undertook several enhancements to the facility. Foremost among these was development and fabrication of a five-degree-of-freedom (5-DoF) optics mount and control system, which translates and tilts the user-provided mirror assembly suspended from its interface plate. Initial Constellation-X tests characterize the performance of the Optical Alignment Pathfinder Two (OAP2) for the large Spectroscopy X-ray Telescope (SXT) and of demonstration mirror assemblies for the Hard X-ray Telescope (HXT). With the Centroid Detector Assembly (CDA), used for precision alignment of the Chandra (nee AXAF) mirrors, the Constellation-X SXT Team optically aligned the individual mirrors of the OAPZ at GSFC. The team then developed set-up and alignment procedures, including transfer of the alignment from the optical alignment facility at GSFC to the X-ray test facility at MSFC, using a reference flat and fiducials. The OAPZ incorporates additional ancillary features --- fixed aperture mask and movable sub-aperture mask --- to facilitate X-ray characterization of the optics. Although the OAPZ was designed to- have low sensitivity to temperature offsets and gradients, analyses showed the necessity of active temperature control for the X-ray performance testing. Thus, the Smithsonian Astrophysical Observatory (SAO) implemented a thermal control and monitoring system, designed to hold the OAP2 close to its assembly.

Studies on dynamic behavior of rotating mirrors

NASA Astrophysics Data System (ADS)

Li, Jingzhen; Sun, Fengshan; Gong, Xiangdong; Huang, Hongbin; Tian, Jie

2005-02-01

A rotating mirror is a kernel unit in a Miller-type high speed camera, which is both as an imaging element in optical path and as an element to implement ultrahigh speed photography. According to Schardin"s Principle, information capacity of an ultrahigh speed camera with rotating mirror depends on primary wavelength of lighting used by the camera and limit linear velocity on edge of the rotating-mirror: the latter is related to material (including specifications in technology), cross-section shape and lateral structure of rotating mirror. In this manuscript dynamic behavior of high strength aluminium alloy rotating mirrors is studied, from which it is preliminarily shown that an aluminium alloy rotating mirror can be absolutely used as replacement for a steel rotating-mirror or a titanium alloy rotating-mirror in framing photographic systems, and it could be also used as a substitute for a beryllium rotating-mirror in streak photographic systems.

Silicon Carbide Technologies for Lightweighted Aerospace Mirrors

NASA Astrophysics Data System (ADS)

Matson, L.; Chen, M.; Deblonk, B.; Palusinski, I.

The use of monolithic glass and beryllium to produce lightweighted aerospace mirror systems has reached its limits due to the long lead times, high processing costs, environmental effects and launch load/weight requirements. New material solutions and manufacturing processes are required to meet DoD's directed energy weapons, reconnaissance/surveillance, and secured communications needs. Over the past several years the Air Force, MDA, and NASA has focused their efforts on the fabrication, lightweighting, and scale-up of numerous silicon carbide (SiC) based materials. It is anticipated that SiC can be utilized for most applications from cryogenic to high temperatures. This talk will focus on describing the SOA for these (near term) SiC technology solutions for making mirror structural substrates, figuring and finishing technologies being investigated to reduce cost time and cost, and non-destructive evaluation methods being investigated to help eliminate risk. Mirror structural substrates made out of advanced engineered materials (far term solutions) such as composites, foams, and microsphere arrays for ultra lightweighting will also be briefly discussed.

Testing of a Stacked Core Mirror for UV Applications

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Kirk, Charles S.; Maffett, Steven P.; Abplanalp, Calvin E.; Stahl, H. Philip; Eng, Ron; Arnold, William R. Sr.

2013-01-01

Advanced Ultraviolet, Optical, Near-Infrared (UVOIR) Mirror Technology Development (AMTD) Testing Summary: (1) Processing of the stacked core mirror converged very quickly using ion figuring. (2) Results show no significant PSD change due to ion figuring in spatial periods smaller than 20mm. (3) Global surface figure limited by mount repeatability

Fabrication, Testing, Coating and Alignment of Fast Segmented Optics

DTIC Science & Technology

2006-05-25

mirror segment, a 100 mm thick Zerodur mirror blank was purchased from Schott. Figure 2 shows the segment and its support for polishing and testing in...Polishing large off-axis segments of fast primary mirrors 2. Testing large segments in an off-axis geometry 3. Alignment of multiple segments of a large... mirror 4. Coatings that reflect high-intensity light without distorting the substrate These technologies are critical because of several unique

Structural and Aerodynamic Optimization of UltraLightweight Technology for Research in Astronomy (ULTRA)

NASA Astrophysics Data System (ADS)

Etzel, P. B.; Martin, R.; Romeo, R.; Fesen, R.; Hale, R.; Taghavi, R.; Anthony-Twarog, B. J.; Shawl, S. J.; Twarog, B. A.

2004-12-01

The focus of ULTRA (see poster by Twarog et al.) is a three-year plan to develop and test ultralightweight technology for research applications in astronomy. The goal is to demonstrate that a viable alternative exists to traditional glass-mirror technology by designing, fabricating, and testing a research telescope prototype comprising fiber reinforced plastic (CFRP) materials. To date, several mirror designs have been tested. The main goal in the first year has been to develop a 0.4m diameter mirror and OTA that serve as prototypes for the 1m telescope design. Mirrors of 0.4m diameter have been successfully fabricated which yield diffraction limited images. This poster will include a display of the complete OTA (including optics), optics test results, and astronomical images taken with prototype mirrors. Finite element analysis has been used to evaluate the OTA and mirror designs. Preliminary design details were incorporated in a knowledge-based system. Adaptive Modeling Language (AML), an object oriented programming language developed by Technosoft, Inc., was used to develop a parameterized geometric model of the preliminary design. The system can generate mirrors with radials/circumferentials, tube core substructures, as well as modeling the support structure. Computational fluid dynamics analyses were performed for sweep, inclination and ambient wind speed. Finite element analyses were performed for core density and arrangement, skin thickness, back-surface curvature, spider configuration and arrangement of the OTA, while the loading conditions considered thus far are thermal, inertial, and aerodynamic pressure loads. Experimental tests, including ultrasonic nondestructive evaluations, infrared imaging, modal testing, and wind tunnel tests, have been performed on the first prototype mirror, with the primary goal of validating analytical models and identifying potential manufacturing induced variations to be expected among "like" mirrors. Support of this work by NSF grants AST-0320784 and AST-0321247, NASA grant NCC5-600, Kansas University, and San Diego State University is gratefully acknowledged

A 3D Polymer Based Printed Two-Dimensional Laser Scanner

NASA Astrophysics Data System (ADS)

Oyman, H. A.; Gokdel, Y. D.; Ferhanoglu, O.; Yalcinkaya, A. D.

2016-10-01

A two-dimensional (2D) polymer based scanning mirror with magnetic actuation is developed for imaging applications. Proposed device consists of a circular suspension holding a rectangular mirror and can generate a 2D scan pattern. Three dimensional (3D) printing technology which is used for implementation of the device, offers added flexibility in controlling the cross-sectional profile as well as the stress distribution compared to the traditional planar process technologies. The mirror device is developed to meet a portable, miniaturized confocal microscope application in mind, delivering 4.5 and 4.8 degrees of optical scan angles at 111 and 267 Hz, respectively. As a result of this mechanical performance, the resulting microscope incorporating the mirror is estimated to accomplish a field of view (FOV) of 350 µm × 350 µm.

Engineering Specifications derived from Science Requirements

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Arnold, William; Bevan, Ryan M.; Smith, W. Scott; Kirk, Charles S.; Postman, Marc

2013-01-01

Advanced Mirror Technology Development (AMTD) is a multi-year effort to systematically mature to TRL-6 the critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable mission can be considered by the 2020 Decadal Review. This technology must enable missions capable of both general astrophysics & ultra-high contrast observations of exoplanets. To accomplish our objective, we use a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system.

Analytical Verifications in Cryogenic Testing of NGST Advanced Mirror System Demonstrators

NASA Technical Reports Server (NTRS)

Cummings, Ramona; Levine, Marie; VanBuren, Dave; Kegley, Jeff; Green, Joseph; Hadaway, James; Presson, Joan; Cline, Todd; Stahl, H. Philip (Technical Monitor)

2002-01-01

Ground based testing is a critical and costly part of component, assembly, and system verifications of large space telescopes. At such tests, however, with integral teamwork by planners, analysts, and test personnel, segments can be included to validate specific analytical parameters and algorithms at relatively low additional cost. This paper opens with strategy of analytical verification segments added to vacuum cryogenic testing of Advanced Mirror System Demonstrator (AMSD) assemblies. These AMSD assemblies incorporate material and architecture concepts being considered in the Next Generation Space Telescope (NGST) design. The test segments for workmanship testing, cold survivability, and cold operation optical throughput are supplemented by segments for analytical verifications of specific structural, thermal, and optical parameters. Utilizing integrated modeling and separate materials testing, the paper continues with support plan for analyses, data, and observation requirements during the AMSD testing, currently slated for late calendar year 2002 to mid calendar year 2003. The paper includes anomaly resolution as gleaned by authors from similar analytical verification support of a previous large space telescope, then closes with draft of plans for parameter extrapolations, to form a well-verified portion of the integrated modeling being done for NGST performance predictions.

Replicated x-ray optics for space applications

NASA Astrophysics Data System (ADS)

Hudec, René; Pína, Ladislav; Inneman, Adolf

2017-11-01

We report on the program of design and development of X-ray optics for space applications in the Czech Republic. Having more than 30 years background in X-ray optics development for space applications (for use in astronomical X-ray telescopes onboard spacecrafts, before 1989 mostly for Soviet and East European INTERKOSMOS program), we focus nowadays on novel technologies and approaches, thin shell replicated mirrors, as well as studies of light-weight mirrors based on innovative materials such as ceramics. The collaboration includes teams from the Academy of Sciences, Universities, and industry. We will describe and discuss both the history of the development of Xray optics in the Czech Republic and the developed technologies and approaches (with focus on replication technology) as well as recent activities and developments including our participation on the ESA XEUS mirror technology development based on the Agreement between ESA and Czech Government.

Status Report and Lessons Learned from the Univ. of Arizona NMSD

NASA Technical Reports Server (NTRS)

Baiocchi, Dave; Burge, Jim

2003-01-01

We will present the latest generation of space mirror technology being developed at the Univ. of Arizona (UA). Unlike conventional monolithic mirrors, the UA mirrors are completely active in their operation. This allows greater flexibility in the mass, volume and performance specifications. The UA mirror design uses a thin flexible substrate for the optical surface and an actuated lightweight structure for surface accuracy and support. We provide an update on the UA NGST Mirror System Demonstrator (NMSD). The 2-m, f/5 NMSD mirror uses a 2 mm thick glass substrate and weighs 86 pounds. We review the mirror's design, discuss the mythology schemes used to actuate the figure, and present a list of the lessons learned.

Prototyping iridium coated mirrors for x-ray astronomy

NASA Astrophysics Data System (ADS)

Döhring, Thorsten; Probst, Anne-Catherine; Stollenwerk, Manfred; Emmerich, Florian; Stehlíková, Veronika; Inneman, Adolf

2017-05-01

X-ray astronomy uses space-based telescopes to overcome the disturbing absorption of the Earth's atmosphere. The telescope mirrors are operating at grazing incidence angles and are coated with thin metal films of high-Z materials to get sufficient reflectivity for the high-energy radiation to be observed. In addition the optical payload needs to be light-weighted for launcher mass constrains. Within the project JEUMICO, an acronym for "Joint European Mirror Competence", the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague started a collaboration to develop mirrors for X-ray telescopes. The X-ray telescopes currently developed within this Bavarian- Czech project are of Lobster eye type optical design. Corresponding mirror segments use substrates of flat silicon wafers which are coated with thin iridium films, as this material is promising high reflectivity in the X-ray range of interest. The deposition of the iridium films is based on a magnetron sputtering process. Sputtering with different parameters, especially by variation of the argon gas pressure, leads to iridium films with different properties. In addition to investigations of the uncoated mirror substrates the achieved surface roughness has been studied. Occasional delamination of the iridium films due to high stress levels is prevented by chromium sublayers. Thereby the sputtering parameters are optimized in the context of the expected reflectivity of the coated X-ray mirrors. In near future measurements of the assembled mirror modules optical performances are planned at an X-ray test facility.

[Motion control of moving mirror based on fixed-mirror adjustment in FTIR spectrometer].

PubMed

Li, Zhong-bing; Xu, Xian-ze; Le, Yi; Xu, Feng-qiu; Li, Jun-wei

2012-08-01

The performance of the uniform motion of the moving mirror, which is the only constant motion part in FTIR spectrometer, and the performance of the alignment of the fixed mirror play a key role in FTIR spectrometer, and affect the interference effect and the quality of the spectrogram and may restrict the precision and resolution of the instrument directly. The present article focuses on the research on the uniform motion of the moving mirror and the alignment of the fixed mirror. In order to improve the FTIR spectrometer, the maglev support system was designed for the moving mirror and the phase detection technology was adopted to adjust the tilt angle between the moving mirror and the fixed mirror. This paper also introduces an improved fuzzy PID control algorithm to get the accurate speed of the moving mirror and realize the control strategy from both hardware design and algorithm. The results show that the development of the moving mirror motion control system gets sufficient accuracy and real-time, which can ensure the uniform motion of the moving mirror and the alignment of the fixed mirror.

Advanced Mirror System Demonstrator (AMSD) Risk Management

NASA Technical Reports Server (NTRS)

Byberg, Alicia; Russell, J. Kevin; Kaukler, Donna; Burdine, Robert V. (Technical Monitor)

2002-01-01

This paper will report risk issues associated with designing, manufacturing, and testing the Advanced Mirror System Demonstrator (AMSD). The Advanced Mirror System Demonstrator (AMSD) will be developed as a lightweight primary mirror system that can be produced at a low cost and with a short manufacturing schedule. This technology will add to the knowledge base for selection for the Next Generation Space Telescope (NGST), Space Based Laser (SBL), Research Laboratory mission (AFRL), and other government agency programs.

Adaptive Optics Facility: control strategy and first on-sky results of the acquisition sequence

NASA Astrophysics Data System (ADS)

Madec, P.-Y.; Kolb, J.; Oberti, S.; Paufique, J.; La Penna, P.; Hackenberg, W.; Kuntschner, H.; Argomedo, J.; Kiekebusch, M.; Donaldson, R.; Suarez, M.; Arsenault, R.

2016-07-01

The Adaptive Optics Facility is an ESO project aiming at converting Yepun, one of the four 8m telescopes in Paranal, into an adaptive telescope. This is done by replacing the current conventional secondary mirror of Yepun by a Deformable Secondary Mirror (DSM) and attaching four Laser Guide Star (LGS) Units to its centerpiece. In the meantime, two Adaptive Optics (AO) modules have been developed incorporating each four LGS WaveFront Sensors (WFS) and one tip-tilt sensor used to control the DSM at 1 kHz frame rate. The four LGS Units and one AO module (GRAAL) have already been assembled on Yepun. Besides the technological challenge itself, one critical area of AOF is the AO control strategy and its link with the telescope control, including Active Optics used to shape M1. Another challenge is the request to minimize the overhead due to AOF during the acquisition phase of the observation. This paper presents the control strategy of the AOF. The current control of the telescope is first recalled, and then the way the AO control makes the link with the Active Optics is detailed. Lab results are used to illustrate the expected performance. Finally, the overall AOF acquisition sequence is presented as well as first results obtained on sky with GRAAL.

VLT deformable secondary mirror: integration and electromechanical tests results

NASA Astrophysics Data System (ADS)

Biasi, R.; Andrighettoni, M.; Angerer, G.; Mair, C.; Pescoller, D.; Lazzarini, P.; Anaclerio, E.; Mantegazza, M.; Gallieni, D.; Vernet, E.; Arsenault, R.; Madec, P.-Y.; Duhoux, P.; Riccardi, A.; Xompero, M.; Briguglio, R.; Manetti, M.; Morandini, M.

2012-07-01

The VLT Deformable secondary is planned to be installed on the VLT UT#4 as part of the telescope conversion into the Adaptive Optics test Facility (AOF). The adaptive unit is based on the well proven contactless, voice coil motor technology that has been already successfully implemented in the MMT, LBT and Magellan adaptive secondaries, and is considered a promising technical choice for the forthcoming ELT-generation adaptive correctors, like the E-ELT M4 and the GMT ASM. The VLT adaptive unit has been recently assembled after the completion of the manufacturing and modular test phases. In this paper, we present the most relevant aspects of the system integration and report the preliminary results of the electromechanical tests performed on the unit. This test campaign is a typical major step foreseen in all similar systems built so far: thanks to the metrology embedded in the system, that allows generating time-dependent stimuli and recording in real time the position of the controlled mirror on all actuators, typical dynamic response quality parameters like modal settling time, overshoot and following error can be acquired without employing optical measurements. In this way the system dynamic and some aspect of its thermal and long term stability can be fully characterized before starting the optical tests and calibrations.

Solar Thermal Propulsion Test Facility

NASA Technical Reports Server (NTRS)

1999-01-01

Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. This photograph shows a fully assembled solar thermal engine placed inside the vacuum chamber at the test facility prior to testing. The 20- by 24-ft heliostat mirror (not shown in this photograph) has a dual-axis control that keeps a reflection of the sunlight on the 18-ft diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move theNation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth orbit, rapid travel throughout the solar system, and exploration of interstellar space.

Production of the 4.26 m ZERODUR mirror blank for the Advanced Technology Solar telescope (ATST)

NASA Astrophysics Data System (ADS)

Jedamzik, Ralf; Werner, Thomas; Westerhoff, Thomas

2014-07-01

The Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST) will be the most powerful solar telescope in the world. It is currently being built by the Association of Universities for Research in Astronomy (AURA) in a height of 3000 m above sea level on the mountain Haleakala of Maui, Hawaii. The primary mirror blank of diameter 4.26 m is made of the extremely low thermal expansion glass ceramic ZERODUR® of SCHOTT AG Advanced Optics. The DKIST primary mirror design is extremely challenging. With a mirror thickness of only 78 to 85 mm it is the smallest thickness ever machined on a mirror of 4.26 m in diameter. Additionally the glassy ZERODUR® casting is one of the largest in size ever produced for a 4 m class ZERODUR® mirror blank. The off axis aspherical mirror surface required sophisticated grinding procedures to achieve the specified geometrical tolerance. The small thickness of about 80 mm required special measures during processing, lifting and transport. Additionally acid etch treatment was applied to the convex back-surface and the conical shaped outer diameter surface to improve the strength of the blank. This paper reports on the challenging tasks and the achievements on the material property and dimensional specification parameter during the production of the 4.26 m ZERODUR® primary mirror blank for AURA.

Band-to-Band Misregistration of the Images of MODIS On-Board Calibrators and Its Impact to Calibration

NASA Technical Reports Server (NTRS)

Wang, Zhipeng; Xiong, Xiaoxiong

2017-01-01

The MODIS instruments aboard Terra and Aqua satellites are radiometrically calibrated on-orbit with a set of onboard calibrators (OBC) including a solar diffuser (SD), a blackbody (BB) and a space view (SV) port through which the detectors can view the dark space. As a whisk-broom scanning spectroradiometer, thirty-six MODIS spectral bands are assembled in the along-scan direction on four focal plane assemblies (FPA). These bands capture images of the same target sequentially with the motion of a scan mirror. Then the images are co-registered on board by delaying appropriate band dependent amount of time depending on the band locations on the FPA. While this co-registration mechanism is functioning well for the "far field" remote targets such as Earth view (EV) scenes or the Moon, noticeable band-to-band misregistration in the along-scan direction has been observed for near field targets, in particular the OBCs. In this paper, the misregistration phenomenon is presented and analyzed. It is concluded that the root cause of the misregistration is that the rotating element of the instrument, the scan mirror, is displaced from the focus of the telescope primary mirror. The amount of the misregistration is proportional to the band location on the FPA and is inversely proportional to the distance between the target and the scan mirror. The impact of this misregistration to the calibration of MODIS bands is discussed. In particular, the calculation of the detector gain coefficient m1 of bands 8-16 (412 nm 870 nm) is improved by up to 1.5% for Aqua MODIS.

3-D optical profilometry at micron scale with multi-frequency fringe projection using modified fibre optic Lloyd's mirror technique

NASA Astrophysics Data System (ADS)

Inanç, Arda; Kösoğlu, Gülşen; Yüksel, Heba; Naci Inci, Mehmet

2018-06-01

A new fibre optic Lloyd's mirror method is developed for extracting 3-D height distribution of various objects at the micron scale with a resolution of 4 μm. The fibre optic assembly is elegantly integrated to an optical microscope and a CCD camera. It is demonstrated that the proposed technique is quite suitable and practical to produce an interference pattern with an adjustable frequency. By increasing the distance between the fibre and the mirror with a micrometre stage in the Lloyd's mirror assembly, the separation between the two bright fringes is lowered down to the micron scale without using any additional elements as part of the optical projection unit. A fibre optic cable, whose polymer jacket is partially stripped, and a microfluidic channel are used as test objects to extract their surface topographies. Point by point sensitivity of the method is found to be around 8 μm, changing a couple of microns depending on the fringe frequency and the measured height. A straightforward calibration procedure for the phase to height conversion is also introduced by making use of the vertical moving stage of the optical microscope. The phase analysis of the acquired image is carried out by One Dimensional Continuous Wavelet Transform for which the chosen wavelet is the Morlet wavelet and the carrier removal of the projected fringe patterns is achieved by reference subtraction. Furthermore, flexible multi-frequency property of the proposed method allows measuring discontinuous heights where there are phase ambiguities like 2π by lowering the fringe frequency and eliminating the phase ambiguity.

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-03-16

This photo shows the High Resolution Camera (HRC) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being integrated with the High Resolution Mirror Assembly (HRMA) in Marshall Space Flight Center's (MSFC's) 24-foot Vacuum Chamber at the X-Ray Calibration Facility (XRCF). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most poweful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRC is one of the two instruments used at the focus of CXO, where it will detect x-rays reflected from an assembly of eight mirrors. The unique capabilities of the HRC stem from the close match of its imaging capability to the focusing of the mirrors. When used with CXO mirrors, the HRC makes images that reveal detail as small as one-half an arc second. This is equivalent to the ability to read a newspaper at a distance of 1 kilometer. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components relatedto x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

History of Chandra X-Ray Observatory

NASA Image and Video Library

1997-03-16

This photo shows the High Resolution Camera (HRC) for the Chandra X-Ray Observatory (CXO), formerly Advanced X-Ray Astrophysics Facility (AXAF), being integrated with the High Resolution Mirror Assembly (HRMA) in Marshall Space Flight Center's (MSFC's) 24-foot Vacuum Chamber at the X-Ray Calibration Facility (XRCF). The AXAF was renamed CXO in 1999. The CXO is the most sophisticated and the world's most powerful x-ray telescope ever built. It observes x-rays from high-energy regions of the universe, such as hot gas in the remnants of exploded stars. The HRC is one of the two instruments used at the focus of CXO, where it will detect x-rays reflected from an assembly of eight mirrors. The unique capabilities of the HRC stem from the close match of its imaging capability to the focusing of the mirrors. When used with CXO mirrors, the HRC makes images that reveal detail as small as one-half an arc second. This is equivalent to the ability to read a newspaper at a distance of 1 kilometer. MSFC's XRCF is the world's largest, most advanced laboratory for simulating x-ray emissions from distant celestial objects. It produces a space-like environment in which components related to x-ray telescope imaging are tested and the quality of their performances in space is predicted. TRW, Inc. was the prime contractor for the development of the CXO and NASA's MSFC was responsible for its project management. The Smithsonian Astrophysical Observatory controls science and flight operations of the CXO for NASA from Cambridge, Massachusetts. The CXO was launched July 22, 1999 aboard the Space Shuttle Columbia (STS-93).

Band-to-Band Misregistration of the Images of MODIS Onboard Calibrators and Its Impact on Calibration

NASA Technical Reports Server (NTRS)

Wang, Zhipeng; Xiong, Xiaoxiong

2017-01-01

The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard Terra and Aqua satellites are radiometrically calibrated on-orbit with a set of onboard calibrators (OBCs), including a solar diffuser, a blackbody, and a space view port through which the detectors can view the dark space. As a whisk-broom scanning spectroradiometer, thirty-six MODIS spectral bands are assembled in the along-scan direction on four focal plane assemblies (FPAs). These bands capture images of the same target sequentially with the motion of a scan mirror. Then the images are coregistered onboard by delaying the appropriate band-dependent amount of time, depending on the band locations on the FPA. While this coregistration mechanismis functioning well for the far-field remote targets such as earth view scenes or the moon, noticeable band-to-band misregistration in the along-scan direction has been observed for near field targets, particularly in OBCs. In this paper, the misregistration phenomenon is presented and analyzed. It is concluded that the root cause of the misregistration is that the rotating element of the instrument, the scan mirror, is displaced from the focus of the telescope primary mirror. The amount of the misregistrationis proportional to the band location on the FPA and is inversely proportional to the distance between the target and the scan mirror. The impact of this misregistration on the calibration of MODIS bands is discussed. In particular, the calculation of the detector gain coefficient m1of bands 8-16 (412 nm 870 nm) is improved by up to 1.5% for Aqua MODIS.

Annual Industrial Capabilities Report to Congress

DTIC Science & Technology

1999-02-01

suspension systems is not a concern. Deformable Mirrors (September 1998) The atmosphere, temperature variations, and vibration distort optical system...images. Deformable mirrors can compensate for these effects in real time. They are used in surveillance optics, laser weapons, and astronomical telescopes...This assessment investigated the availability of current and potential deformable mirror producers, and possible alternative technologies. The

Biomimetics and astronomical X-ray optics

NASA Astrophysics Data System (ADS)

Hudec, R.; Remisova, K.

2017-07-01

Some sea and water animals have strange mirror eyes which have (or might have) potential application in science and technology in general and in X—ray astrophysics in particular. While the principles of mirror eyes of decapods (lobsters, crayfishes) are already applied in space and ground—based imaging experiments, the mirror eyes of specific fishes are still very little investigated.

The Advanced Gamma-ray Imaging System (AGIS): Schwarzschild-Couder (SC) Telescope Mechanical and Optical System Design

NASA Astrophysics Data System (ADS)

Guarino, V.; Vassiliev, V.; Buckley, J.; Byrum, K.; Falcone, A.; Fegan, S.; Finley, J.; Hanna, D.; Kaaret, P.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Romani, R.; Wagner, R.; Woods, M.

2009-05-01

The concept of a future ground-based gamma-ray observatory, AGIS, in the energy range 20 GeV to 200 TeV is based on an array of 50-100 imaging atmospheric Cherenkov telescopes (IACTs). The anticipated improvement of AGIS sensitivity, angular resolution, and reliability of operation imposes demanding technological and cost requirements on the design of IACTs. In this submission, we focus on the optical and mechanical systems for a novel Schwarzschild-Couder two-mirror aplanatic optical system originally proposed by Schwarzschild. Emerging new mirror production technologies based on replication processes, such as cold and hot glass slumping, cured CFRP, and electroforming, provide new opportunities for cost effective solutions for the design of the optical system. We explore capabilities of these mirror fabrication methods for the AGIS project and alignment methods for optical systems. We also study a mechanical structure which will provide support points for mirrors and camera design driven by the requirement of minimizing the deflections of the mirror support structures.

Cesic: optomechanical technology last development results and new HBCesic highly light weighted space mirror development including corrective function 7th international conference on space optics, october 2008

NASA Astrophysics Data System (ADS)

Devilliers, Christophe; Kroedel, Mathias

2017-11-01

Thales-Alenia-Space and ECM has developed a new SiC ceramic composite to produce very lightweight space mirrors and structure. Cesicmade by ECM has been selected for its own intrinsic properties ( high specific Young modulus, high conductivity , low CTE, high strength for a ceramics) and its large manufacturing capabilities. Recently a full monolithic space instrument for earth observation, with a monolithic Cesicstructure and with Cesicmirrors has been designed, manufactured and space qualified and is now ready for launch. The Cesictelescope assembly has been tested under shock environment, vibration loads, and full qualification thermal environment. All these qualification tests were done directly on the flight model. Extensive development has been also performed to design, size, manufacture and test a very light weight reflector shell made as a single part. This 1 meter reflective shell has an areal density of less than 10 Kg/m2 has been manufactured with its surface grounded to the bi parabolic shape. Such challenging areal density has requested a very thin skin associated with a ribs thickness of less than 2mm. In order to demonstrate the high stability and strength of Cesicthe reflector has been tested successfully under very aggressive environment up to 350°C and also an acoustic test with flight representative levels was successfully performed. To produce future very lightweight space mirrors ECM develop with the support of Thales-Alenia-Space since some years an improved version of Cesicceramic, called HB-Cesic©. HB-Cesicmade by ECM is developed for its higher intrinsic properties, Young modulus, strength and especially its direct polishing capabilities down to 3 nm micro-roughness. One of the major targets for this development was also to overcome size limitations of the C/C raw material of currently around 1x1 m to produce mirror up to 3,5 m diameter out of a single C/C raw material block. Under ESA study a 600 mm mirror with a surface density of only 18 Kg/m2 has been designed, sized and manufactured and is currently under polishing at SESO. The polishing to a micro-roughness of far less than 20 nm RMS without expensive overcoatings has been already validated on mirrors up to 800 mm. This 600 mm mirror will be polished to a WFE of less than 20 nm, and afterwards the mirror will be tested under cryogenic environment to measure the WFE evolution between ambient and cryo. The mirror is equipped with a system for focus and astigmatism modification. During the cryo test this system will be activated at cryo temperature to also demonstrate the function of this system. This correction system is developed for future large mirrors for interferometric nulling or aperture synthesis missions like the Darwin mission . For such missions very large and very lightweight mirrors up to 3,5 m diameter with an areal density of less than 25 Kg/m2 are required and thank to the HBCesictechnology such performance is now feasible.

Measuring the In-Process Figure, Final Prescription, and System Alignment of Large Optics and Segmented Mirrors Using Lidar Metrology

NASA Technical Reports Server (NTRS)

Ohl, Raymond; Slotwinski, Anthony; Eegholm, Bente; Saif, Babak

2011-01-01

The fabrication of large optics is traditionally a slow process, and fabrication capability is often limited by measurement capability. W hile techniques exist to measure mirror figure with nanometer precis ion, measurements of large-mirror prescription are typically limited to submillimeter accuracy. Using a lidar instrument enables one to measure the optical surface rough figure and prescription in virtuall y all phases of fabrication without moving the mirror from its polis hing setup. This technology improves the uncertainty of mirror presc ription measurement to the micron-regime.

Large Binocular Telescope project

NASA Astrophysics Data System (ADS)

Hill, John M.; Salinari, Piero

2003-02-01

The Large Binocular Telescope (LBT) Project is a collaboration between institutions in Arizona, Germany, Italy, and Ohio. The first of two 8.4-meter borosilicate honeycomb primary mirrors for LBT is being polished at the Steward Observatory Mirror Lab this year. The second of the two 8.4-meter mirror blanks waits its turn in the polishing queue. The baseline optical configuration of LBT includes adaptive infrared secondaries of a Gregorian design. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4-arcminute diameter field-of-view. These adaptive secondary mirrors with 672 voice-coil actuators are now in the early stages of fabrication. The interferometric focus combining the light from the two 8.4-meter primaries will reimage the two folded Gregorian focal planes to three central locations for phased array imaging. The telescope elevation structure accommodates swing arm spiders which allow rapid interchange of the various secondary and tertiary mirrors as well as prime focus cameras. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The telescope structure was fabricated and pre-assembled in Italy by Ansaldo-Camozzi in Milan. The structure was disassembled, packed and shipped to Arizona. The enclosure was built on Mt. Graham and is ready for telescope installation.

Wavelength tunable ultrafast fiber laser via reflective mirror with taper structure.

PubMed

Fang, Li; Huang, Chuyun; Liu, Ting; Gogneau, Noelle; Bourhis, Eric; Gierak, Jacques; Oudar, Jean-Louis

2016-12-20

Laser sources with a controllable flexible wavelength have found widespread applications in optical fiber communication, optical sensing, and microscopy. Here, we report a tunable mode-locked fiber laser using a graphene-based saturable absorber and a tapered mirror as an end mirror in the cavity. The phase layer in the mirror is precisely etched by focused ion beam (FIB) milling technology, and the resonant wavelength of the mirror shifts correspond to the different etch depths. By scanning the tapered mirror mechanically, the center wavelength of a mode-locked fiber laser can be continuously tuned from 1562 to 1532 nm, with a pulse width in the sub-ps level and repetition rate of 27 MHz.

COI NMSD Hybrid Mirror

NASA Technical Reports Server (NTRS)

Mehle, Greg; Stahl, Phil (Technical Monitor)

2002-01-01

This presentation provides an overview of the development of the 1.6 meter hybrid mirror demonstrator for the NGST Mirror System Demonstrator (NMSD) program. The COI design approach for the NGST program combines the optical performance of glass, with the high specific stiffness capabilities of composite materials The foundation technologies being exploited in the development of the hybrid mirror focus upon precision Composite Materials for cryogenic operation, and non-contact optical processing (ion figuring) of the lightweight mirror surface. The NGST Mirror System Demonstrator (NMSD) has been designed and built by Composite Optics, Inc. (COI) with optical processing performed by SAGEM (REOSC). The sponsors of these efforts are the NASA Marshall and Goddard Space Flight Centers.

Perspectives on Schools: Metaphors and Management in Education.

ERIC Educational Resources Information Center

Bredeson, Paul V.

1988-01-01

Metaphors, whether verbalized, symbolized, or camouflaged, reveal school administrators' perceptions, values, and behaviors. This article examines how specific metaphors (assembly line, ticking clock, garden, mirror of society, museum, and candy machine) contribute to an understanding of school characteristics and administration. Training and…

First Giant Mirror for the ESO VLT Ready at REOSC

NASA Astrophysics Data System (ADS)

1995-11-01

The REOSC Contract In 1989, the European Southern Observatory (ESO), the European Organisation for Astronomy, awarded to REOSC, a subsidiary of the SFIM Group and located in Saint Pierre du Perray (France), a comprehensive contract for the polishing of four 8.2-metre diameter mirrors for the unit telescopes of the ESO Very Large Telescope (VLT) project. These mirrors are the largest ever manufactured and polished. This contract comprises not only the polishing and high-precision optical testing of each giant mirror, but also the safe condition of transportation of the blanks which were manufactured by Schott Glaswerke in Mainz (Germany). In order to fulfill the contract, REOSC conceived, built and equipped a novel, high-tech workshop which would allow to polish and test the mirrors, each of which has a surface area of more than 50 square metres. First 8.2-Metre Mirror is Ready and within Specifications The REOSC polishing facility for giant mirrors was built in Saint Pierre du Perray, just south of Paris. It is equipped with two machines: one for grinding and the other for polishing the mirrors, and both with 150-actuator systems that support the thin and flexible mirrors. All equipment is computer controlled. State-of-the-art interferometers probe the accuracy of the mirror surface as the polishing proceeds; they are installed at the top level of the facility in a 30-metre high tower, at the centre of the mirror's radius of curvature. The success of the work at REOSC is now evident by the fact that careful measurements of the first mirror earlier this month have shown that the final optical surface is correct to within 0.00005 millimetres. For illustration, this corresponds to an accuracy of only 1 millimetre deviation over a surface with a diameter of 165 kilometres (equivalent to the entire Paris area)! ESO Receives the First VLT Mirror After having been carefully placed in a special transport box designed by REOSC, the first mirror blank, weighing 23.5 tons and with a replacement value of about 20 million DEM, was transported from Mainz to Saint Pierre du Perray in July 1993. The shaping and polishing phases lasted two years and were completed in October 1995. After one month's hard work, dedicated to optical and mechanical verifications by ESO and REOSC, the mirror's various characteristics have now been found to be in accordance with the contract specifications. Following the technical acceptance, the first mirror was re-installed in its transport container on November 13, 1995. It will thereafter be formally handed over to ESO during a ceremony at REOSC on Tuesday, November 21, 1995. The mirror will be stored at the REOSC facility until its future departure to ESO's VLT Observatory on Cerro Paranal, a 2650 m high summit in the Andean Cordillera in northern Chile. Here it will be installed in the first VLT unit telescope, soon after the assembly of the mechanical parts has been completed. Future Plans at REOSC The polishing of the second VLT mirror, as well as the grinding of the third mirror which was transported from Mainz to Saint Pierre du Perray at the beginning of October 1995, have already started. The transport of the fourth blank will take place in March 1996. With the construction, in a subsequent phase, of a workshop of more than 6000 square metres and mostly dedicated to space and astronomy, the SFIM group will have invested more than 50 million French Francs at the Saint Pierre du Perray site alone. The group is also involved in the contract related to the actuator support system; this is a clear indication of its determination to maintain its position within this scientific-technological market. In addition to the ESO VLT mirrors, REOSC will also polish the two 8.2-metre diameter mirrors of the Gemini programme of the Association of Universities for Research in Astronomy (AURA) in the United States. This important work was entrusted REOSC, following an international call for tenders, in which also US firms participated. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Tuning the Cavity Size and Chirality of Self-Assembling 3D DNA Crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simmons, Chad R.; Zhang, Fei; MacCulloch, Tara

The foundational goal of structural DNA nanotechnology—the field that uses oligonucleotides as a molecular building block for the programmable self-assembly of nanostructured systems—was to use DNA to construct three-dimensional (3D) lattices for solving macromolecular structures. The programmable nature of DNA makes it an ideal system for rationally constructing self-assembled crystals and immobilizing guest molecules in a repeating 3D array through their specific stereospatial interactions with the scaffold. In this work, we have extended a previously described motif (4 × 5) by expanding the structure to a system that links four double-helical layers; we use a central weaving oligonucleotide containing amore » sequence of four six-base repeats (4 × 6), forming a matrix of layers that are organized and dictated by a series of Holliday junctions. In addition, we have assembled mirror image crystals (l-DNA) with the identical sequence that are completely resistant to nucleases. Bromine and selenium derivatives were obtained for the l- and d-DNA forms, respectively, allowing phase determination for both forms and solution of the resulting structures to 3.0 and 3.05 Å resolution. Both right- and left-handed forms crystallized in the trigonal space groups with mirror image 3-fold helical screw axes P32 and P31 for each motif, respectively. The structures reveal a highly organized array of discrete and well-defined cavities that are suitable for hosting guest molecules and allow us to dictate a priori the assembly of guest–DNA conjugates with a specified crystalline hand.« less

The Advanced Technology Large-Aperture Space Telescope (ATLAST) Technology Roadmap

NASA Technical Reports Server (NTRS)

Stahle, Carl; Balasubramanian, K.; Bolcar, M.; Clampin, M.; Feinberg, L.; Hartman, K.; Mosier, C.; Quijada, M.; Rauscher, B.; Redding, D.;

Novel ultra-lightweight and high-resolution MEMS x-ray optics

NASA Astrophysics Data System (ADS)

Mitsuishi, Ikuyuki; Ezoe, Yuichiro; Takagi, Utako; Mita, Makoto; Riveros, Raul; Yamaguchi, Hitomi; Kato, Fumiki; Sugiyama, Susumu; Fujiwara, Kouzou; Morishita, Kohei; Nakajima, Kazuo; Fujihira, Shinya; Kanamori, Yoshiaki; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa; Maeda, Ryutaro

2009-05-01

We have been developing ultra light-weight X-ray optics using MEMS (Micro Electro Mechanical Systems) technologies.We utilized crystal planes after anisotropic wet etching of silicon (110) wafers as X-ray mirrors and succeeded in X-ray reflection and imaging. Since we can etch tiny pores in thin wafers, this type of optics can be the lightest X-ray telescope. However, because the crystal planes are alinged in certain directions, we must approximate ideal optical surfaces with flat planes, which limits angular resolution of the optics on the order of arcmin. In order to overcome this issue, we propose novel X-ray optics based on a combination of five recently developed MEMS technologies, namely silicon dry etching, X-ray LIGA, silicon hydrogen anneal, magnetic fluid assisted polishing and hot plastic deformation of silicon. In this paper, we describe this new method and report on our development of X-ray mirrors fabricated by these technologies and X-ray reflection experiments of two types of MEMS X-ray mirrors made of silicon and nickel. For the first time, X-ray reflections on these mirrors were detected in the angular response measurements. Compared to model calculations, surface roughness of the silicon and nickel mirrors were estimated to be 5 nm and 3 nm, respectively.

A Space Imaging Concept Based on a 4-meter Spun-Cast Borosilicate Monolithic Primary Mirror

DTIC Science & Technology

2010-06-01

borosilicate monolithic primary mirror 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Steve West, S.H... Mirror Technology Days, Boulder, Colorado, USA, 7-9 June 2010. 14. ABSTRACT The goal of this effort is to produce the largest monolithic telescope...capable of being lifted by a Delta IV or Atlas V EELV to 500 km. A strategy using a 4 m borosilicate mirror is proposed. A preliminary architecture was

Research in the Optical Sciences.

DTIC Science & Technology

1981-01-30

technology, as mirrors for laser weapons, and as protec- tive coatings in laser warfare. Three phases of the study were considered: 91. Laboratory...performance of simple metal coatings used on concentrating and flat-plate mirrors subject to high solar flux and heat, and on military mirrors used for...atI i :-a;t ;oil Cutiponlit -1of th >na"Cl I I C ’k lig ht cani be indi(ependent iv measured. 12 The scattering levels of most of the studied mirrors

Electromagnetic deformable mirror for space applications

NASA Astrophysics Data System (ADS)

Kuiper, S.; Doelman, N.; Overtoom, T.; Nieuwkoop, E.; Russchenberg, T.; van Riel, M.; Wildschut, J.; Baeten, M.; Spruit, H.; Brinkers, S.; Human, J.

2017-09-01

To increase the collecting power and to improve the angular imaging resolution, space telescopes are evolving towards larger primary mirrors. The aerial density of the telescope mirrors needs to be kept low, however, to be compatible with the launch requirements. A light-weight (primary) mirror will introduce additional optical aberrations to the system. These may be caused by for instance manufacturing errors, gravity release and thermo-elastic effects. Active Optics (AO) is a key candidate technology to correct for the resultant wave front aberrations [1].

Engineers Work on the James Webb Space Telescope

NASA Image and Video Library

2017-12-08

Engineers at Ball Aerospace test the Wavefront Sensing and Control testbed to ensure that the 18 primary mirror segments and one secondary mirror on JWST work as one. The test is performed on a 1/6 scale model of the JWST mirrors. Credit: NASA/Northrop Grumman/Ball Aerospace To read more about the James Webb Space Telescope go to: www.nasa.gov/topics/technology/features/partnerships.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

High-performance coatings for micromechanical mirrors.

PubMed

Gatto, Alexandre; Yang, Minghong; Kaiser, Norbert; Heber, Jörg; Schmidt, Jan Uwe; Sandner, Thilo; Schenk, Harald; Lakner, Hubert

2006-03-01

High-performance coatings for micromechanical mirrors were developed. The high-reflective metal systems can be integrated into the technology of MOEMS, such as spatial light modulators and microscanning mirrors from the near-infrared down to the vacuum-ultraviolet spectral regions. The reported metal designs permit high optical performances to be merged with suitable mechanical properties and fitting complementary metal-oxide semiconductor compatibility.

Technology Applications Report 1993

DTIC Science & Technology

1994-01-01

Companies Find Riches in Acousto-Optics 39 BMD Research Spurs Growth of Optics Start-Up 40 Improved Mirror Shaping Techniques to Correct Hubble...without destroying spectral bands along the horizon- tal axis. By developing toroidal mirrors that correct the vertical image, Chromex, Inc. was...which provide better image resolution and wider field-of-view than standard spherical-shaped mirrors , but are more difficult to make. PACE can

Advanced UVOIR Mirror Technology Development (AMTD) for Very Large Space Telescopes

NASA Technical Reports Server (NTRS)

Postman, Marc; Soummer, Remi; Sivramakrishnan, Annand; Macintosh, Bruce; Guyon, Olivier; Krist, John; Stahl, H. Philip; Smith, W. Scott; Mosier, Gary; Kirk, Charles;

Polishers around the globe: an overview on the market of large astronomical mirrors

NASA Astrophysics Data System (ADS)

Döhring, Thorsten

2014-07-01

Astronomical mirrors are key elements in modern optical telescopes, their dimensions are usually large and their specifications are demanding. Only a limited number of skilled companies respectively institutions around the world are able to master the challenge to polish an individual astronomical mirror, especially in dimensions above one meter. This paper presents an overview on the corresponding market including a listing of polishers around the globe. Therefore valuable information is provided to the astronomical community: Polishers may use the information as a global competitor database, astronomers and project managers may get more transparency on potential suppliers, and suppliers of polishing equipment may learn about unknown potential customers in other parts of the world. An evaluation of the historical market demand on large monolithic astronomical mirrors is presented. It concluded that this is still a niche market with a typical mean rate of 1-2 mirrors per year. Polishing of such mirrors is an enabling technology with impact on the development of technical know-how, public relation, visibility and reputation of the supplier. Within a corresponding technical discussion different polishing technologies are described. In addition it is demonstrated that strategic aspects and political considerations are influencing the selection of the optical finisher.

Review of infrared scene projector technology-1993

NASA Astrophysics Data System (ADS)

Driggers, Ronald G.; Barnard, Kenneth J.; Burroughs, E. E.; Deep, Raymond G.; Williams, Owen M.

1994-07-01

The importance of testing IR imagers and missile seekers with realistic IR scenes warrants a review of the current technologies used in dynamic infrared scene projection. These technologies include resistive arrays, deformable mirror arrays, mirror membrane devices, liquid crystal light valves, laser writers, laser diode arrays, and CRTs. Other methods include frustrated total internal reflection, thermoelectric devices, galvanic cells, Bly cells, and vanadium dioxide. A description of each technology is presented along with a discussion of their relative benefits and disadvantages. The current state of each methodology is also summarized. Finally, the methods are compared and contrasted in terms of their performance parameters.

Thermal Analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8 Meter Primary Mirror

NASA Technical Reports Server (NTRS)

Hornsby, Linda; Stahl, H. Philip; Hopkins, Randall C.

2010-01-01

The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The primary mirror will be maintained at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop(R) SINDA/FLUINT(R) was used for the thermal analysis and the radiation environment was analyzed using RADCAD(R). A XX node model was executed in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew or 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the environment which influences the thermal performance. All assumptions that were used in the analysis are also documented. Parametric analyses are summarized for design parameters including primary mirror coatings and sunshade configuration. Estimates of mirror heater power requirements are reported. The thermal model demonstrates results for the primary mirror heated from the back side and edges using a heater system with multiple independently controlled zones.

Large aperture deformable mirror with a transferred single-crystal silicon membrane actuated using large-stroke PZT Unimorph Actuators

NASA Technical Reports Server (NTRS)

Hishinumat, Yoshikazu; Yang, Eui - Hyeok (EH)

2005-01-01

We have demonstrated a large aperture (50 mm x 50 mm) continuous membrane deformable mirror (DM) with a large-stroke piezoelectric unimorph actuator array. The DM consists of a continuous, large aperture, silicon membrane 'transferred' in its entirety onto a 20 x 20 piezoelectric unimorph actuator array. A PZT unimorph actuator, 2.5 mm in diameter with optimized PZT/Si thickness and design showed a deflection of 5.7 [m at 20V. An assembled DM showed an operating frequency bandwidth of 30 kHz and influence function of approximately 30%.

Synthesis of tumor necrosis factor α for use as a mirror-image phage display target.

PubMed

Petersen, Mark E; Jacobsen, Michael T; Kay, Michael S

2016-06-21

Tumor Necrosis Factor alpha (TNFα) is an inflammatory cytokine that plays a central role in the pathogenesis of chronic inflammatory disease. Here we describe the chemical synthesis of l-TNFα along with the mirror-image d-protein for use as a phage display target. The synthetic strategy utilized native chemical ligation and desulfurization to unite three peptide segments, followed by oxidative folding to assemble the 52 kDa homotrimeric protein. This synthesis represents the foundational step for discovering an inhibitory d-peptide with the potential to improve current anti-TNFα therapeutic strategies.

Cluster optical coding: from biochips to counterfeit security

NASA Astrophysics Data System (ADS)

Haglmueller, Jakob; Alguel, Yilmaz; Mayer, Christian; Matyushin, Viacheslav; Bauer, Georg; Pittner, Fritz; Leitner, Alfred; Aussenegg, Franz R.; Schalkhammer, Thomas G.

2004-07-01

Spatially tuned resonant nano-clusters allow high local field enhancement when exited by electromagnetic radiation. A number of phenomena had been described and subsequently applied to novel nano- and bionano-devices. Decisive for these types of devices and sensors is the precise nanometric assembly, coupling the local field surrounding a cluster to allow resonance with other elements interacting with this field. In particular, the distance cluster-mirror or cluster-fluorophore gives rise to a variety of enhancement phenomena. High throughput transducers using metal cluster resonance technology are based on surface-enhancement of metal cluster light absorption (SEA). The optical property for the analytical application of metal cluster films is the so-called anomalous absorption. At a well defined nanometric distance of a cluster to a mirror the reflected electromagnetic field has the same phase at the position of the absorbing cluster as the incident fields. This feedback mechanism strongly enhances the effective cluster absorption coefficient. The system is characterised by a narrow reflection minimum. Based on this SEA-phenomenon (licensed to and further developed and optimized by NovemberAG, Germany Erlangen) a number of commercial products have been constructed. Brandsealing(R) uses the patented SEA cluster technology to produce optical codings. Cluster SEA thin film systems show a characteristic color-flip effect and are extremely mechanically and thermally robust. This is the basis for its application as an unique security feature. The specific spectroscopic properties as e.g. narrow band multi-resonance of the cluster layers allow the authentication of the optical code which can be easily achieved with a mobile hand-held reader developed by november AG and Siemens AG. Thus, these features are machine-readable which makes them superior to comparable technologies. Cluster labels are available in two formats: as a label for tamper-proof product packaging, and as a direct label, where label and logo are permanently applied directly and unremovable to the product surface. Together with Infineon Technologies and HUECK FOLIEN, the SEA technology is currently developed as a direct label for e.g. SmartCards.

Formation Flying of Components of a Large Space Telescope

NASA Technical Reports Server (NTRS)

Mettler, Edward; Quadrelli, Marco; Breckenridge, William

2009-01-01

A conceptual space telescope having an aperture tens of meters wide and a focal length of hundreds of meters would be implemented as a group of six separate optical modules flying in formation: a primary-membrane-mirror module, a relay-mirror module, a focal-plane-assembly module containing a fast steering mirror and secondary and tertiary optics, a primary-mirror-figure-sensing module, a scanning-electron-beam module for controlling the shape of the primary mirror, and a sunshade module. Formation flying would make it unnecessary to maintain the required precise alignments among the modules by means of an impractically massive rigid structure. Instead, a control system operating in conjunction with a metrology system comprising optical and radio subsystems would control the firing of small thrusters on the separate modules to maintain the formation, thereby acting as a virtual rigid structure. The control system would utilize a combination of centralized- and decentralized-control methods according to a leader-follower approach. The feasibility of the concept was demonstrated in computational simulations that showed that relative positions could be maintained to within a fraction of a millimeter and orientations to within several microradians.

Comparison of ring-focus image profile with predictions for the AXAF VETA-I test

NASA Technical Reports Server (NTRS)

Zissa, David E.

1993-01-01

The X-ray test of the largest pair of nearly cylindrical mirrors for the Advanced X-ray Astrophysics Facility (AXAF) was completed in October 1991 at Marshall Space Flight Center. The test assembly was named the Verification Engineering Test Article I (VETA-I). The ring-focus portion of the test measured the imaging quality of azimuthal sections of VETA-I. This gives information about the core of the on-orbit image. The finite source distance, VETA-I mirror spacing, and VETA-I structural deformation caused the core of the image to be spread over a diameter of nearly 4 arc seconds at the VETA-I overall focus. The results of a preliminary analysis of the ring-focus data and the implications for the on-orbit image of the telescope are discussed. An upper limit for the on-orbit encircled-energy fraction at 1 arc second diameter was determined to be 0.82 at 0.277 keV X-ray energy. This assumes that the bottoms of the mirrors in the VETA-I arrangement are representative of the mirror surfaces and that the on-orbit system would be aligned using a combination of preliminary measurements and predictions for the mirror surface shapes.

2D tilting MEMS micro mirror integrating a piezoresistive sensor position feedback

NASA Astrophysics Data System (ADS)

Lani, S.; Bayat, D.; Despont, M.

2015-02-01

An integrated position sensor for a dual-axis electromagnetic tilting mirror is presented. This tilting mirror is composed of a silicon based mirror directly assembled on a silicon membrane supported by flexible beams. The position sensors are constituted by 4 Wheatstone bridges of piezoresistors which are fabricated by doping locally the flexible beams. A permanent magnet is attached to the membrane and the scanner is mounted above planar coils deposited on a ceramic substrate to achieve electromagnetic actuation. The performances of the piezoresistive sensors are evaluated by measuring the output signal of the piezoresistors as a function of the tilt of the mirror and the temperature. White light interferometry was performed for all measurement to measure the exact tilt angle. The minimum detectable angle with such sensors was 30µrad (around 13bits) in the range of the minimum resolution of the interferometer. The tilt reproducibility was 0.0186%, obtained by measuring the tilt after repeated actuations with a coil current of 50mA during 30 min and the stability over time was 0.05% in 1h without actuation. The maximum measured tilt angle was 6° (mechanical) limited by nonlinearity of the MEMS system.

Optical measurements of the mirrors and of the interferential filter of the Metis coronagraph on Solar Orbiter

NASA Astrophysics Data System (ADS)

Sandri, P.; Sarra, P.; Radaelli, P.; Morea, D.; Melich, R.; Berlicki, A.; Antonucci, E.; Castronuovo, M. M.; Fineschi, S.; Naletto, G.; Nicolini, G.; Romoli, M.

2017-08-01

The paper describes the wavefront error measurements of the concave ellipsoidal mirrors M1 and M2, of the concave spherical mirror M0 and of the flat interferential filter IF of the Metis coronagraph. Metis is an inverted occultation coronagraph on board of the ESA Solar Orbiter mission providing a broad-band imaging of the full corona in linearly polarized visible-light (580 - 640 nm) and a narrow-band imaging of the full corona in the ultraviolet Lyman α (121.6 nm). Metis will observe the solar outer atmosphere from a close distance to the Sun as 0.28 A.U. and from up to 35deg out-of-ecliptic. The measurements of wavefront error of the mirrors and of the interferential filter of Metis have been performed in a ISO5 clean room both at component level and at assembly level minimizing, during the integration, the stress introduced by the mechanical hardware. The wavefront error measurements have been performed with a digital interferometer for mirrors M0, M1 and M2 and with a Shack-Hartmann wavefront sensor for the interferential filter.

The CETUS Probe Mission Concept 1.5m Optical Telescope Assembly: A high A-Omega approach for ultraviolet astrophysics

NASA Astrophysics Data System (ADS)

Hull, Anthony; Heap, Sara; Woodruff, Robert; Mehle, Greg; Tomic, Matt; Dodson, Kelly; Burge, Jim; Lewis, Ben; Valente, Martin; Kendrick, Stephen E.; Purves, Lloyd; Danchi, William

2018-01-01

We describe the 1.5-m Cosmic Evolution Through Ultraviolet Spectroscopy (CETUS) Optical Telescope Assembly (OTA), a Three Mirror Anastigmat (TMA), providing a large usable focus, which permits non-shared locations for several Ultraviolet (UV) instruments. NASA has selected CETUS as a Probe Mission Concept for consideration by The Decadal Survey ASTRO2020. CETUS will fly in a L2 halo orbit and typically be pointing between 85 degrees and 135 degrees from the sun, and looking at galaxies at redshifts between z=1 and z=2. However, the CETUS payload also will be able to rapidly slew to sun angles between 85 degrees and 180 degrees to reach objects of opportunity, an example of which is a neutron star merger event. CETUS thermal stability starts with lightweighted ZERODUR® mirrors, that are an excellent thermal match to a metering structure of carbon fiber reinforced polymer (CFRP) M55J. This basic passive athermalization approach will be supplemented with controlled heaters, especially at metallic mounts, composite terminations and mechanisms. After launch, solid body metering errors will be optimized by an actuated hexapod in the secondary mirror assembly (SMA). Thus the CETUS telescope can respond to any pointing induced change in solar view factors. Contamination is managed by commissioning heaters radiating to each mirror surface, and a capping shutter over the telescope aperture. The instruments include a wide-field-of-view (WFoV) multi-object spectrometer (MOS), and a complimentary WFoV camera, as well as high-resolution point source Echelle spectrometers (R~40,000). They do not require that the OTA deliver diffraction limited performance over the extent of the instrument wavelength range (115nm to 400nm). The camera and spectrometer each cover a field of view of ~ 1000 arcsec by ~ 1000 arcsec compared to ~ 150 arcsec by ~ 150 arcsec for WFC3 on the Hubble Space Telescope (HST). Thus, the AW (etendue) factor for CETUS is ~700 m^2-arcmin^2, compared to the AW factor for WFC3 on HST which is ~ 25 meter^2-arcmin^2. Thus, CETUS provides a factor of ~30 higher etendue than HST.

Alignment and Distortion-Free Integration of Lightweight Mirrors into Meta-Shells for High-Resolution Astronomical X-Ray Optics

NASA Technical Reports Server (NTRS)

Chan, Kai-Wing; Zhang, William W.; Schofield, Mark J.; Numata, Ai; Mazzarella, James R.; Saha, Timo T.; Biskach, Michael P.; McCelland, Ryan S.; Niemeyer, Jason; Sharpe, Marton V.;

Generating end plug potentials in tandem mirror plasma confinement by heating thermal particles so as to escape low density end stoppering plasmas

DOEpatents

Baldwin, David E.; Logan, B. Grant

1981-01-01

The invention provides a method and apparatus for raising the potential of a magnetic mirror cell by pumping charged particles of the opposite sign of the potential desired out of the mirror cell through excitation, with the pumping being done by an externally imposed field at the bounce frequency of the above charged particles. These pumped simple mirror cells then provide end stoppering for a center mirror cell for the tandem mirror plasma confinement apparatus. For the substantially complete pumping case, the end plugs of a tandem mirror can be up to two orders of magnitude lower in density for confining a given center mirror cell plasma than in the case of end plugs without pumping. As a result the decrease in recirculating power required to keep the system going, the technological state of the art required, and the capital cost are all greatly lowered.

Learning robot actions based on self-organising language memory.

PubMed

Wermter, Stefan; Elshaw, Mark

2003-01-01

In the MirrorBot project we examine perceptual processes using models of cortical assemblies and mirror neurons to explore the emergence of semantic representations of actions, percepts and concepts in a neural robot. The hypothesis under investigation is whether a neural model will produce a life-like perception system for actions. In this context we focus in this paper on how instructions for actions can be modeled in a self-organising memory. Current approaches for robot control often do not use language and ignore neural learning. However, our approach uses language instruction and draws from the concepts of regional distributed modularity, self-organisation and neural assemblies. We describe a self-organising model that clusters actions into different locations depending on the body part they are associated with. In particular, we use actual sensor readings from the MIRA robot to represent semantic features of the action verbs. Furthermore, we outline a hierarchical computational model for a self-organising robot action control system using language for instruction.

Neutron star Interior Composition Explorer (NICER)

NASA Image and Video Library

2017-12-08

NICER Optics Lead Takashi Okajima installs one of NICER’s 56 X-ray “concentrators,” each consisting of 24 concentric foils. To minimize the effects of Earth’s gravity on their alignment, the concentrator assemblies were installed from the outside edges toward the center of the plate that houses them. The payload’s 56 mirror assemblies concentrate X-rays onto silicon detectors to gather data that will probe the interior makeup of neutron stars, including those that appear to flash regularly, called pulsars. The Neutron star Interior Composition Explorer (NICER) is a NASA Explorer Mission of Opportunity dedicated to studying the extraordinary environments — strong gravity, ultra-dense matter, and the most powerful magnetic fields in the universe — embodied by neutron stars. An attached payload aboard the International Space Station, NICER will deploy an instrument with unique capabilities for timing and spectroscopy of fast X-ray brightness fluctuations. The embedded Station Explorer for X-ray Timing and Navigation Technology demonstration (SEXTANT) will use NICER data to validate, for the first time in space, technology that exploits pulsars as natural navigation beacons. Credit: NASA/Goddard/ Keith Gendreau NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Development of Individually Addressable Micro-Mirror-Arrays for Space Applications

NASA Technical Reports Server (NTRS)

Dutta, Sanghamitra B.; Ewin, Audrey J.; Jhabvala, Murzy; Kotecki, Carl A.; Kuhn, Jonathan L.; Mott, D. Brent

2000-01-01

We have been developing a 32 x 32 prototype array of individually addressable Micro-Mirrors capable of operating at cryogenic temperature for Earth and Space Science applications. Micro-Mirror-Array technology has the potential to revolutionize imaging and spectroscopy systems for NASA's missions of the 21st century. They can be used as programmable slits for the Next Generation Space Telescope, as smart sensors for a steerable spectrometer, as neutral density filters for bright scene attenuation etc. The, entire fabrication process is carried out in the Detector Development Laboratory at NASA, GSFC. The fabrication process is low temperature compatible and involves integration of conventional CMOS technology and surface micro-machining used in MEMS. Aluminum is used as the mirror material and is built on a silicon substrate containing the CMOS address circuit. The mirrors are 100 microns x l00 microns in area and deflect by +/- 10 deg induced by electrostatic actuation between two parallel plate capacitors. A pair of thin aluminum torsion straps allow the mirrors to tilt. Finite-element-analysis and closed form solutions using electrostatic and mechanical torque for mirror operation were developed and the results were compared with laboratory performance. The results agree well both at room temperature and at cryogenic temperature. The development demonstrates the first cryogenic operation of two-dimensional Micro-Mirrors with bi-state operation. Larger arrays will be developed meeting requirements for different science applications. Theoretical analysis, fabrication process, laboratory test results and different science applications will be described in detail.

High-precision processing and detection of the high-caliber off-axis aspheric mirror

NASA Astrophysics Data System (ADS)

Dai, Chen; Li, Ang; Xu, Lingdi; Zhang, Yingjie

2017-10-01

To achieve the efficient, controllable, digital processing and high-precision detection of the high-caliber off-axis aspheric mirror, meeting the high-level development needs of the modern high-resolution, large field of space optical remote sensing camera, we carried out the research on high precision machining and testing technology of off-axis aspheric mirror. First, we forming the off-axis aspheric sample with diameter of 574mm × 302mm by milling it with milling machine, and then the intelligent robot equipment was used for off-axis aspheric high precision polishing. Surface detection of the sample will be proceed with the off-axis aspheric contact contour detection technology and offaxis non-spherical surface interference detection technology after its fine polishing using ion beam equipment. The final surface accuracy RMS is 12nm.

A Wafer Transfer Technology for MEMS Adaptive Optics

NASA Technical Reports Server (NTRS)

Yang, Eui-Hyeok; Wiberg, Dean V.

2001-01-01

Adaptive optics systems require the combination of several advanced technologies such as precision optics, wavefront sensors, deformable mirrors, and lasers with high-speed control systems. The deformable mirror with a continuous membrane is a key component of these systems. This paper describes a new technique for transferring an entire wafer-level silicon membrane from one substrate to another. This technology is developed for the fabrication of a compact deformable mirror with a continuous facet. A 1 (mu)m thick silicon membrane, 100 mm in diameter, has been successfully transferred without using adhesives or polymers (i.e. wax, epoxy, or photoresist). Smaller or larger diameter membranes can also be transferred using this technique. The fabricated actuator membrane with an electrode gap of 1.5 (mu)m shows a vertical deflection of 0.37 (mu)m at 55 V.

Dynamic/Jitter Assessment of Multiple Potential HabEx Structural Designs

NASA Technical Reports Server (NTRS)

Knight, J. Brent; Stahl, H. Philip; Singleton, Andy; Hunt, Ron; Therrell, Melissa; Caldwell, Kate; Garcia, Jay; Baysinger, Mike

2017-01-01

One of the driving structural requirements of the Habitable Exo-Planet (HabEx) telescope is to maintain Line Of Sight (LOS) stability between the Primary Mirror (PM) and Secondary Mirror (SM) of = 5 mas. Dynamic analyses of two configurations of a proposed (HabEx) 4 meter off-axis telescope structure were performed to predict effects of jitter on primary/secondary mirror alignment. The dynamic disturbance used as the forcing function was the James Webb Space Telescope reaction wheel assembly vibration emission specification level. The objective of these analyses was to predict "order-of-magnitude" performance for various structural configurations which will roll into efforts to define the HabEx structural design's global architecture. Two variations of the basic architectural design were analyzed. Relative motion between the PM and the SM for each design configuration are reported.

Dynamic/jitter assessment of multiple potential HabEx structural designs

NASA Astrophysics Data System (ADS)

Knight, J. Brent; Stahl, H. Philip; Singleton, Andy; Hunt, Ron; Therrell, Melissa; Caldwell, Kate; Garcia, Jay; Baysinger, Mike

2017-09-01

One of the driving structural requirements of the Habitable Exo-Planet (HabEx) telescope is to maintain Line Of Sight (LOS) stability between the Primary Mirror (PM) and Secondary Mirror (SM) of <= 5 milli-arc seconds (mas). Dynamic analyses of two configurations of a proposed HabEx 4 meter off-axis telescope structure were performed to predict effects of a vibration input on primary/secondary mirror alignment. The dynamic disturbance used as the forcing function was the James Webb Space Telescope reaction wheel assembly vibration emission specification level. The objective of these analyses was to predict "order-of-magnitude" performance for various structural configurations which contribute to efforts in defining the HabEx structural design's global architecture. Two variations of the basic architectural design were analyzed. Relative motion between the PM and the SM for each design configuration are reported.

Shell Separation for Mirror Replication

NASA Technical Reports Server (NTRS)

1999-01-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. Optics replication uses reusable forms, called mandrels, to make telescope mirrors ready for final finishing. MSFC optical physicist Bill Jones monitors a device used to chill a mandrel, causing it to shrink and separate from the telescope mirror without deforming the mirror's precisely curved surface.

Design of Efficient Mirror Adder in Quantum- Dot Cellular Automata

NASA Astrophysics Data System (ADS)

Mishra, Prashant Kumar; Chattopadhyay, Manju K.

2018-03-01

Lower power consumption is an essential demand for portable multimedia system using digital signal processing algorithms and architectures. Quantum dot cellular automata (QCA) is a rising nano technology for the development of high performance ultra-dense low power digital circuits. QCA based several efficient binary and decimal arithmetic circuits are implemented, however important improvements are still possible. This paper demonstrate Mirror Adder circuit design in QCA. We present comparative study of mirror adder cells designed using conventional CMOS technique and mirror adder cells designed using quantum-dot cellular automata. QCA based mirror adders are better in terms of area by order of three.

Space Optic Manufacturing - X-ray Mirror

NASA Technical Reports Server (NTRS)

1998-01-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. This image shows a lightweight replicated x-ray mirror with gold coatings applied.

MEMS deformable mirror for wavefront correction of large telescopes

NASA Astrophysics Data System (ADS)

Manhart, Sigmund; Vdovin, Gleb; Collings, Neil; Sodnik, Zoran; Nikolov, Susanne; Hupfer, Werner

2017-11-01

A 50 mm diameter membrane mirror was designed and manufactured at TU Delft. It is made from bulk silicon by micromachining - a technology primarily used for micro-electromechanical systems (MEMS). The mirror unit is equipped with 39 actuator electrodes and can be electrostatically deformed to correct wavefront errors in optical imaging systems. Performance tests on the deformable mirror were carried out at Astrium GmbH using a breadboard setup with a wavefront sensor and a closed-loop control system. It was found that the deformable membrane mirror is well suited for correction of low order wavefront errors as they must be expected in lightweighted space telescopes.

Fabrication of a TFF-Attached WDM-Type Triplex Transceiver Module Using Silica PLC Hybrid Integration Technology

NASA Astrophysics Data System (ADS)

Han, Young-Tak; Park, Yoon-Jung; Park, Sang-Ho; Shin, Jang-Uk; Lee, Chul-Wook; Ko, Hyunsung; Baek, Yongsoon; Park, Chul-Hee; Kwon, Yoon-Koo; Hwang, Wol-Yon; Oh, Kwang-Ryong; Sung, Heekyung

2006-12-01

An optical triplex transceiver (TRx) module, which consists of thin-film filter (TFF)-attached wavelength-division multiplexer (WDM) and photodiode (PD) carriers, has been fabricated using a silica planar lightwave circuit (PLC) hybrid integration technology. Two types of TFFs were attached to a diced sidewall of a silica-terraced PLC platform to realize the TFF-attached WDM. The PD carriers with a 45° mirror, on which receiving surface-illuminated PDs were bonded, were assembled with the PLC platform to form receiver (Rx) parts. As the main performances of the packaged TRx module, a very clear transmitter (Tx) eye pattern and minimum Rx sensitivity of -25.7 dBm were obtained under a 1.25-Gb/s Tx Rx operation for digital applications. For an analog Rx application, a module responsivity of about 0.8 A/W was achieved, and a second-order intermodulation distortion value of less than -70 dBc at an optical modulation index of 40% was obtained under a two-tone test of 400 and 450 MHz.

Thin glass based packaging and photonic single-mode waveguide integration by ion-exchange technology on board and module level

NASA Astrophysics Data System (ADS)

Brusberg, Lars; Lang, Günter; Schröder, Henning

2011-01-01

The proposed novel packaging approach merges micro-system packaging and glass integrated optics. It provides 3D optical single-mode intra system links to bridge the gap between novel photonic integrated circuits and the glass fibers for inter system interconnects. We introduce our hybrid 3D photonic packaging approach based on thin glass substrates with planar integrated optical single-mode waveguides for fiber-to-chip and chip-to-chip links. Optical mirrors and lenses provide optical mode matching for photonic IC assemblies and optical fiber interconnects. Thin glass is commercially available in panel and wafer formats and characterizes excellent optical and high-frequency properties as reviewed in the paper. That makes it perfect for micro-system packaging. The adopted planar waveguide process based on ion-exchange technology is capable for high-volume manufacturing. This ion-exchange process and the optical propagation are described in detail for thin glass substrates. An extensive characterization of all basic circuit elements like straight and curved waveguides, couplers and crosses proves the low attenuation of the optical circuit elements.

Simulation and modeling of silicon pore optics for the ATHENA x-ray telescope

NASA Astrophysics Data System (ADS)

Spiga, D.; Christensen, F. E.; Bavdaz, M.; Civitani, M. M.; Conconi, P.; Della Monica Ferreira, D.; Knudsen, E. B.; Massahi, S.; Pareschi, G.; Salmaso, B.; Shortt, B.; Tayabaly, K.; Westergaard, N. J.; Wille, E.

2016-07-01

The ATHENA X-ray observatory is a large-class ESA approved mission, with launch scheduled in 2028. The technology of silicon pore optics (SPO) was selected as baseline to assemble ATHENA's optic with more than 1000 mirror modules, obtained by stacking wedged and ribbed silicon wafer plates onto silicon mandrels to form the Wolter-I configuration. Even if the current baseline design fulfills the required effective area of 2 m2 at 1 keV on-axis, alternative design solutions, e.g., privileging the field of view or the off-axis angular resolution, are also possible. Moreover, the stringent requirement of a 5 arcsec HEW angular resolution at 1 keV entails very small profile errors and excellent surface smoothness, as well as a precise alignment of the 1000 mirror modules to avoid imaging degradation and effective area loss. Finally, the stray light issue has to be kept under control. In this paper we show the preliminary results of simulations of optical systems based on SPO for the ATHENA X-ray telescope, from pore to telescope level, carried out at INAF/OAB and DTU Space under ESA contract. We show ray-tracing results, including assessment of the misalignments of mirror modules and the impact of stray light. We also deal with a detailed description of diffractive effects expected in an SPO module from UV light, where the aperture diffraction prevails, to X-rays where the surface diffraction plays a major role. Finally, we analyze the results of X-ray tests performed at the BESSY synchrotron, we compare them with surface finishing measurements, and we estimate the expected HEW degradation caused by the X-ray scattering.

A path planning method used in fluid jet polishing eliminating lightweight mirror imprinting effect

NASA Astrophysics Data System (ADS)

Li, Wenzong; Fan, Bin; Shi, Chunyan; Wang, Jia; Zhuo, Bin

2014-08-01

With the development of space technology, the design of optical system tends to large aperture lightweight mirror with high dimension-thickness ratio. However, when the lightweight mirror PV value is less than λ/10 , the surface will show wavy imprinting effect obviously. Imprinting effect introduced by head-tool pressure has become a technological barrier in high-precision lightweight mirror manufacturing. Fluid jet polishing can exclude outside pressure. Presently, machining tracks often used are grating type path, screw type path and pseudo-random path. On the edge of imprinting error, the speed of adjacent path points changes too fast, which causes the machine hard to reflect quickly, brings about new path error, and increases the polishing time due to superfluous path. This paper presents a new planning path method to eliminate imprinting effect. Simulation results show that the path of the improved grating path can better eliminate imprinting effect compared to the general path.

Space Science

NASA Image and Video Library

1999-04-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. MSFC's Space Optics Manufacturing Technology Center (SOMTC) has grinding and polishing equipment ranging from conventional spindles to custom-designed polishers. These capabilities allow us to grind precisely and polish a variety of optical devices, including x-ray mirror mandrels. This image shows Charlie Griffith polishing the half-meter mandrel at SOMTC.

Manufacture of a 1.7m prototype of the GMT primary mirror segments

NASA Astrophysics Data System (ADS)

Martin, H. M.; Burge, J. H.; Miller, S. M.; Smith, B. K.; Zehnder, R.; Zhao, C.

2006-06-01

We have nearly completed the manufacture of a 1.7 m off-axis mirror as part of the technology development for the Giant Magellan Telescope. The mirror is an off-axis section of a 5.3 m f/0.73 parent paraboloid, making it roughly a 1:5 model of the outer 8.4 m GMT segment. The 1.7 m mirror will be the primary mirror of the New Solar Telescope at Big Bear Solar Observatory. It has a 2.7 mm peak-to-valley departure from the best-fit sphere, presenting a serious challenge in terms of both polishing and measurement. The mirror was polished with a stressed lap, which bends actively to match the local curvature at each point on the mirror surface, and works for asymmetric mirrors as well as symmetric aspheres. It was measured using a hybrid reflective-diffractive null corrector to compensate for the mirror's asphericity. Both techniques will be applied in scaled-up versions to the GMT segments.

JPRS Report, Science & Technology Europe

DTIC Science & Technology

1988-07-27

materials research under microgravity conditions, such as ELLI, AMF of MHF ( Mirror Heating Facility) the Zone Melt- ing Furnace is a resistance-heated...pendently controlled zones. This is another advantage of a resistance-heated furnace over a mirror heating facil- ity. When the experiment requires a...zone, the subdivision into several heating zones will be preferable to the single light focus of a mirror heating facility. In 1987/88, following

AXAF Coordinate Transformation at XRCF

NASA Technical Reports Server (NTRS)

He, Helen; McDowell, Jonathan; Conroy, Maureen

1997-01-01

Coordinate transformation between focal plane and detector pixel systems must be handled carefully at the X-ray Calibration Facility (XRCF) as it will be during flight. The High Resolution Mirror Assembly (HRMA) X-ray Detection System (HXDS) stage dithers, and the five-axis mount (FAM) attachment points underwent various types of motion during testing. At the XRCF when the FAM moved, the Science Instrument Module (SIM) travel direction was not necessarily aligned with the mirror axis motion, and, in addition, an arbitrary position offset had to be calibrated. Misalignment from the mirror axis was assessed by measuring its displacement from the boresight configuration of the default FAM frame, and the HXDS stage was monitored for motion from the default FAM reference point. Mirror position, prescribed in a mirror modal coordinate system, was measured in HRMA pitch and yaw axes. Prior to corrections for dithering and FAM movement, the coordinate data at XRCF also had to be corrected for possible misalignments of the mirror mount relative to XRCF and the default FAM axes due to the movement of the FAM feet. Those misalignments were processed in terms of yaw-pitch-roll Euler angles in the mirror nodal coordinate, and in the default FAM frame, respectively. An AXAF Science Center (ASC) coordinate library, pixlib, has been built to support these coordinate transformations and was used during x-ray calibration at the George C. Marshall Space Flight Center, Huntsville, AL. The design and implementation of this library will be discussed.

Development of a Mirror Pointing Mechanism for an Atmospheric Gas Measurement Instrument

NASA Technical Reports Server (NTRS)

Graham, Michael; Belous, Adel; Brown, Jeffrey; Podolske, James

1998-01-01

Development of the Open Path Tunable Infrared Monitor of the Atmosphere (OPTIMA) instrument involved designing a pair of motion systems that could maintain a precise alignment and spatial distance between two mirrors installed on the NASA DC-8 research laboratory aircraft. This is the first airborne optical instrument that allows direct measurement of the gases in the freestream airflow on the exterior of the aircraft. One mirror is mounted within a specially constructed open port cavity in the cabin of the aircraft and the second is mounted 6 meters away on top of the inboard port side (number 2) engine pylon. Three co-aligned laser beams are reflected between the two mirrors 64 times in a Herriott pattern. The resulting sample path length of 384 meters is used to perform a spectral absorption analysis of the airflow between the mirrors. To compensate for normal wing movement and engine oscillations both mirrors were designed as continuously driven mechanisms to maintain alignment within allowable limits. The motion systems of the two mirror assemblies provide five degrees of freedom and are designed to maintain a pointing accuracy within seven arc-sec with a response frequency in 6xcess of 10 Hz. The pylon motion system incorporates controlled pitch and yaw movement. The fuselage motion system compensates for pitch variation as well as linear translation for focal length and vertical aiming of the laser beam via a controlled beam guidance mechanism.

Next Generation Space Telescope Ultra-Lightweight Mirror Program

NASA Technical Reports Server (NTRS)

Bilbro, James W.

1998-01-01

The Next Generation Space Telescope is currently envisioned as a eight meter diameter cryogenic deployable telescope that will operate at the earth sun libration point L2. A number of different designs are being examined within NASA and under industry studies by Ball Aerospace, Lockheed-Martin and TRW. Although these designs differ in many respects, they all require significant advancements in the state-of-the-art with respect to large diameter, ultra-lightweight, mirrors. The purpose of this paper is to provide insight into the current status of the mirror development program NGST is a tremendously ambitious undertaking that sets the mark for new NASA missions. In order to achieve the weight, cost and performance requirements of NGST, the primary mirror must be made lighter, cheaper and better than anything that has ever been done. In order to accomplish this an aggressive technology program has been put in place. The scope of the program was determined by examining historically what has been accomplished; assessing recent technological advances in fabrication and testing; and evaluating the effect of these advances relative to enabling the manufacture of lightweight mirrors that meet NGST requirements. As it is currently envisioned, the primary mirror for NGST is on the order of eight meters in diameter, it is to be diffraction limited at a wave length of 2 microns and has an overall weight requirement of 15 kilograms per square meter. Two large scale demonstration projects are under way along with a number of smaller scale demonstrations on a variety of mirror materials and concepts. The University of Arizona (UA) mirror concept is based around a 2mm thick Borosilicate glass face sheet mounted to a composite backplane structure via actuators for mirror figure correction. The Composite Optics Inc.(COI) concept consists of a 3.2mm thick Zerodur face sheet bonded to a composite support structure which in turn is mounted to a composite backplane structure via actuators for mirror phasing. These mirrors are due to be performance tested in ambient conditions in the fall of '98, and cryogenically tested in the spring of '99. The smaller scale efforts include the following: Beryllium is being investigated at Ball Aerospace, Electroform nickel is being investigated in-house at MSFC, Chemical Vapor Deposition (CVD) Silicon Carbide (SiC) is being investigated at Morton International Silicon mirrors are being investigated at Schafer, Carbon Fiber Reinforced Silicon Carbide (CSIC) is being investigated at IABG. SiC at SSG, Composite mirrors at COI, pyrolyzed graphite mirrors at Ultramet, reaction bonded SiC mirrors at Xinetics, along with techniques for lightweighting using waterjets at Waterjet Technology Inc. are all being investigated under the Small Business innovative Research Program SBIR program. A procurement for a third large scale demonstration (nominally 1.5m in diameter) is being planned for release this fall.

Thermal Testing of a Stacked Core Mirror for UV Applications

NASA Technical Reports Server (NTRS)

Matthews, Gary; Kirk, Charles S.; Maffett, Steven; Hanson, Craig; Eng, Ron; Stahl, H. Philip

2013-01-01

The ASTRO2010 Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. Under Science and Technology funding, NASA's Marshall Space Flight Center and ITT Exelis have developed a more cost effective process to make 4m monolithic spaceflight UV quality, low areal density, thermally and dynamically stable primary mirrors. A proof of concept mirror was built and tested down to 250K which would allow imaging out to 2.5 microns. This mirror was thermally tested at the Marshall Spaceflight Center to understand the thermal changes between the processing temperature of 293K and the potential low end of the operational temperature of 250K. Isothermal testing results and front plate gradient results have been evaluated and compared to analysis predictions. Measurement of gravity effects on surface figure will be compared to analytical predictions. Future testing of a larger Pathfinder mirror will also be discussed.

Mass production of silicon pore optics for ATHENA

NASA Astrophysics Data System (ADS)

Wille, Eric; Bavdaz, Marcos; Collon, Maximilien

2016-07-01

Silicon Pore Optics (SPO) provide high angular resolution with low effective area density as required for the Advanced Telescope for High Energy Astrophysics (Athena). The x-ray telescope consists of several hundreds of SPO mirror modules. During the development of the process steps of the SPO technology, specific requirements of a future mass production have been considered right from the beginning. The manufacturing methods heavily utilise off-the-shelf equipment from the semiconductor industry, robotic automation and parallel processing. This allows to upscale the present production flow in a cost effective way, to produce hundreds of mirror modules per year. Considering manufacturing predictions based on the current technology status, we present an analysis of the time and resources required for the Athena flight programme. This includes the full production process starting with Si wafers up to the integration of the mirror modules. We present the times required for the individual process steps and identify the equipment required to produce two mirror modules per day. A preliminary timeline for building and commissioning the required infrastructure, and for flight model production of about 1000 mirror modules, is presented.

Hi-speed compact deformable mirror: status, applications, and perspectives

NASA Astrophysics Data System (ADS)

Rooms, F.; Camet, S.; Curis, J.-F.

2010-02-01

Membrane deformable mirrors based on magnetic actuators have been known for years. State-of-the-art deformable mirrors usually have large strokes but low bandwidth. Furthermore, this bandwidth decreases with the diameter. In this paper, we present the results of a new actuator principle based on magnetic forces allowing high bandwidth (up to a few kHz), very large stroke (>30μm) with a record pitch of 1.5mm. The benefits of this technology will be presented for three applications: astronomy, vision science and microscopy. The parameters of the mirrors have been tuned such that the inter-actuator stroke of the deformable (more than 2.0μm) in order to fit the atmosphere turbulence characteristics. In vision science, efforts have been made to correct both simultaneously the low and high order aberrations (more than 45μm of wavefront correction on astigmatism and focus). Finally, we will demonstrate how we have developed a deformable mirror able to correct spherical aberrations (microscopy). The last part of the article is devoted to give some perspectives about this technology.

Pixel switching of epitaxial Pd/YHx/CaF2 switchable mirrors

PubMed

Kerssemakers; van der Molen SJ; Koeman; Gunther; Griessen

2000-08-03

Exposure of rare-earth films to hydrogen can induce a metal-insulator transition, accompanied by pronounced optical changes. This 'switchable mirror' effect has received considerable attention from theoretical, experimental and technological points of view. Most systems use polycrystalline films, but the synthesis of yttrium-based epitaxial switchable mirrors has also been reported. The latter form an extended self-organized ridge network during initial hydrogen loading, which results in the creation of micrometre-sized triangular domains. Here we observe homogeneous and essentially independent optical switching of individual domains in epitaxial switchable mirrors during hydrogen absorption. The optical switching is accompanied by topographical changes as the domains sequentially expand and contract; the ridges block lateral hydrogen diffusion and serve as a microscopic lubricant for the domain oscillations. We observe the correlated changes in topology and optical properties using in situ atomic force and optical microscopy. Single-domain phase switching is not observed in polycrystalline films, which are optically homogeneous. The ability to generate a tunable, dense pattern of switchable pixels is of technological relevance for solid-state displays based on switchable mirrors.

Ground to on-orbit alignment study of the WFIRST wide-field channel and resulting changes in the telescope architecture

NASA Astrophysics Data System (ADS)

Hagopian, John; Armani, Nerses; Bartusek, Lisa; Casey, Tom; Content, Dave; Conturie, Yves; Gao, Guangjun; Jurling, Alden; Marx, Cathy; Marzouk, Joe; Pasquale, Bert; Smith, J. Scott; Tang, Hong; Whipple, Arthur

2017-08-01

The Wide-Field Infrared Survey Telescope (WFIRST) mission[1] is the top-ranked large space mission in the New Worlds, New Horizon (NWNH) Decadal Survey of Astronomy and Astrophysics. WFIRST will settle essential questions in both exoplanet and dark energy research and will advance topics ranging from galaxy evolution to the study of objects within the galaxy. The WFIRST mission uses a repurposed 2.4-m Forward Optical Telescope assembly (FOA), which, when completed with new aft optics will be an Integrated Optical Assembly (IOA). WFIRST is equipped with a Wide Field Instrument (WFI) and a Coronagraph Instrument (CGI). An Instrument Carrier (IC) meters these payload elements together and to the spacecraft bus (S/C). A distributed ground system receives the data, uploads commands and software updates, and processes the data. After transition from the study phase, Pre-Phase-A (a.k.a., "Cycle 6") design to NASA Phase A formulation, a significant change to the IOA was initiated; including moving the tertiary mirror from the instrument package to a unified three-mirror anastigmat (TMA) placement, that provides a wide 0.28-sq° instrumented field of view to the Wide Field Instrument (WFI). In addition, separate relays from the primary and secondary mirror feed the Wide Field Instrument (WFI) and Coronagraph Instrument (CGI). During commissioning the telescope is aligned using wavefront sensing with the WFI[2]. A parametric and Monte-Carlo analysis was performed, which determined that alignment compensation with the secondary mirror alone degraded performance in the other instruments. This led to the addition of a second compensator in the WFI optical train to alleviate this concern. This paper discusses the trades and analyses that were performed and resulting changes to the WFIRST telescope architecture.

Vibration measurements of the Daniel K. Inouye Solar Telescope mount, Coudé rotator, and enclosure assemblies

NASA Astrophysics Data System (ADS)

McBride, William R.; McBride, Daniel R.

2016-08-01

The Daniel K. Inouye Solar Telescope (DKIST) will be the largest solar telescope in the world, with a 4-meter off-axis primary mirror and 16 meter rotating Coudé laboratory within the telescope pier. The off-axis design requires a mount similar to an 8-meter on-axis telescope. Both the telescope mount and the Coudé laboratory utilize a roller bearing technology in place of the more commonly used hydrostatic bearings. The telescope enclosure utilizes a crawler mechanism for the altitude axis. As these mechanisms have not previously been used in a telescope, understanding the vibration characteristics and the potential impact on the telescope image is important. This paper presents the methodology used to perform jitter measurements of the enclosure and the mount bearings and servo system in a high-noise environment utilizing seismic accelerometers and high dynamic-range data acquisition equipment, along with digital signal processing (DSP) techniques. Data acquisition and signal processing were implemented in MATLAB. In the factory acceptance testing of the telescope mount, multiple accelerometers were strategically located to capture the six axes-of-motion of the primary and secondary mirror dummies. The optical sensitivity analysis was used to map these mirror mount displacements and rotations into units of image motion on the focal plane. Similarly, tests were done with the Coudé rotator, treating the entire rotating instrument lab as a rigid body. Testing was performed by recording accelerometer data while the telescope control system performed tracking operations typical of various observing scenarios. The analysis of the accelerometer data utilized noise-averaging fast Fourier transform (FFT) routines, spectrograms, and periodograms. To achieve adequate dynamic range at frequencies as low as 3Hz, the use of special filters and advanced windowing functions were necessary. Numerous identical automated tests were compared to identify and select the data sets with the lowest level of external interference. Similar testing was performed on the telescope enclosure during the factory test campaign. The vibration of the enclosure altitude and azimuth mechanisms were characterized. This paper details jitter tests using accelerometers placed in locations that allowed the motion of the assemblies to be measured while the control system performed various moves typical of on-sky observations. The measurements were converted into the rigid body motion of the structures and mapped into image motion using the telescope's optical sensitivity analysis.

Self-Assembly of Hierarchical DNA Nanotube Architectures with Well-Defined Geometries.

PubMed

Jorgenson, Tyler D; Mohammed, Abdul M; Agrawal, Deepak K; Schulman, Rebecca

2017-02-28

An essential motif for the assembly of biological materials such as actin at the scale of hundreds of nanometers and beyond is a network of one-dimensional fibers with well-defined geometry. Here, we demonstrate the programmed organization of DNA filaments into micron-scale architectures where component filaments are oriented at preprogrammed angles. We assemble L-, T-, and Y-shaped DNA origami junctions that nucleate two or three micron length DNA nanotubes at high yields. The angles between the nanotubes mirror the angles between the templates on the junctions, demonstrating that nanoscale structures can control precisely how micron-scale architectures form. The ability to precisely program filament orientation could allow the assembly of complex filament architectures in two and three dimensions, including circuit structures, bundles, and extended materials.