The ground calibration of the NewATHENA mirror poses significant challenges owing to its unprecedented size, mass, and focal length. VERT-X is an innovative calibration facility designed to tackle this exceptionally demanding task. It relies on an X-ray parallel beam, generated by a micro-focus source positioned at the focus of an X-ray collimator. A raster-scan mechanism enables the beam movement, covering all NewATHENA optics at varying off-axis angles. The compactness of the concept offers several benefits, including the vertical geometry which implies minimal PSF degradation due to lateral gravity. Furthermore, this allows for a flexible choice of location. Indeed one of the most important feature of VERT-X is its contiguity with the mirror integration facility. The driving factor in the VERT-X design is to meet the NewATHENA calibration requirement for Half- Energy Width (HEW) accuracy at 0.1”. Key contributors to the error budget in the VERT-X design include the source size, collimator error, and raster-scan pointing accuracy. This paper provides an overview of the current status of the development of these critical parts.
The MUlti-slit Solar Explorer (MUSE) is a NASA medium-class explorer mission that is currently in phase B and scheduled for launch no earlier than 2027. The MUSE science investigation aims to use high-resolution and high-cadence spectroscopic and imaging EUV observations of the solar atmosphere to understand the multi-scale physical processes that heat the multi-million-degree solar corona, drive the source of the solar wind, and cause solar activity (flares and coronal mass ejections) that lead to space weather that impacts Earth. MUSE will consist of an EUV context imager and an EUV spectrograph, both requiring normal incidence mirrors with a very high level of polishing and figuring, in order to allow high-resolution imaging and spectroscopy. The mission is led by Lockheed Martin Solar and Astrophysics Laboratory (LMSAL). The payload is being developed by LMSAL and the Center for Astrophysics (CfA) at the Harvard Smithsonian Astrophysical Observatory, while INAF-OAB will produce the focusing mirrors with the financial support of the Italian Space Agency (ASI). In this paper, we describe the first steps that are being taken in the procurement of the focusing mirrors in Zerodur, the work plan with the ion beam figuring and the pitch tool aimed at bringing the surface defects within the specification. Additionally, we describe the metrology system that we are setting up to detect the residual deviation to the final shape.
The BEaTriX (Beam Expander Testing X-ray) facility, being completed at INAF-Brera Astronomical Observatory, will represent an important step in the acceptance roadmap of Silicon Pore Optics mirror modules, and so ensure the final angular resolution of the ATHENA X-ray telescope. Aiming at establishing the final angular resolution that can be reached and the respective fabrication/positioning tolerances, we have been dealing with a set of comprehensive optical simulations. Simulations based on wave optics were carried out to predict the collimation performances of the paraboloidal mirror, including the effect of surface errors obtained from metrology. Full-ray-tracing routines were subsequently employed to simulate the full beamline. Finally, wavefront propagation simulation allowed us assessing the sensitivity and the response of a wavefront sensor that will be utilized for the qualification of the collimated beam. We report the simulation results and the methodologies we adopted.
Ariel (Atmospheric Remote-Sensing Infrared Exoplanet Large Survey) has been adopted as the M4 mission for ESA “Cosmic Vision” program. Launch is scheduled for 2029. ARIEL will study exoplanet atmospheres through transit spectroscopy with a 1 m class telescope optimized in the waveband between 1.95 and 7.8 μm and operating in cryogenic conditions in the temperature range 40-50 K. Aluminum alloy 6061, in the T651 temper, was chosen as baseline material for telescope mirror substrates and supporting structures, following a trade-off study. To improve mirrors reflectivity within the operating waveband and to protect the aluminum surface from oxidation, a protected silver coating with space heritage was selected and underwent a qualification campaign during Phase B1 of the mission, with the goal of demonstrating a sufficient level of technology maturity. The qualification campaign consisted of two phases: a first set of durability and environmental tests conducted on a first batch of coated aluminum samples, followed by a set of verification tests performed on a second batch of samples coated alongside a full-size demonstrator of Ariel telescope primary mirror. This study presents the results of the verification tests, consisting of environmental (humidity and temperature cycling) tests and chemical/mechanical (abrasion, adhesion, cleaning) tests performed on the samples, and abrasion tests performed on the demonstrator, by means of visual inspections and reflectivity measurements.
Atmospheric Remote-Sensing Infrared Exoplanet Large Survey (Ariel) has been adopted as ESA “Cosmic Vision” M4 mission, with launch scheduled for 2029. Ariel is based on a 1 m class telescope optimized for spectroscopy in the waveband between 1.95 and 7.8 μm, operating in cryogenic conditions in the range 40–50 K. Aluminum has been chosen as baseline material for the telescope mirrors substrate, with a metallic coating to enhance reflectivity and protect from oxidation and corrosion. As part of Phase B1, leading to SRR and eventually mission adoption, a protected silver coating with space heritage has been selected and will undergo a qualification process. A fundamental part of this process is assuring the integrity of the coating layer and performance compliance in terms of reflectivity at the telescope operating temperature. To this purpose, a set of flat sample disks have been cut and polished from the same baseline aluminum alloy as the telescope mirror substrates, and the selected protected silver coating has been applied to them by magnetron sputtering. The disks have then been subjected to a series of cryogenic temperature cycles to assess coating performance stability. This study presents the results of visual inspection, reflectivity measurements and atomic force microscopy (AFM) on the sample disks before and after the cryogenic cycles.
FLORIS (FLuorescence Imaging Spectrometer) is the single High-Resolution Spectrometer instrument of the FLEX (FLuorescence EXplorer) mission, currently under development by the European Space Agency as the eighth Earth Explorer Mission. The goal of the mission is the monitoring of the chlorophyll fluorescence of plants giving information about their photosynthetic activity.
Leonardo Avionics & Space System Division is the prime contractor for the FLORIS Instrument for which Media Lario is manufacturing the QM unit of the spherical mirror included in the High-Resolution Spectrometer (HRSPE), hereafter called HRM mirror.
The High-Resolution Mirror is a 250-mm diameter spherical mirror with a radius of curvature of approximately 440 mm. For the mirror substrate, Leonardo has selected the Aluminium alloy AlSi40, a special alloy with 40% Silicon content, coated with a hard polishing layer of Nickel Phosphorus (NiP), deposited by electroless chemical process. The Silicon content allows this special Aluminium alloy to have the same coefficient of thermal expansion (CTE) of the NiP layer, therefore preventing thermal deformations deriving from the bimetallic effect. The mirror structure is light-weighted to approximately 2.8 kg. The required wave-front error of the mirror is better than 0.5 fringes PV, while the surface microroughness has been specified at 0.5 nm RMS due to stringent straylight requirements of the FLORIS instrument.
Media Lario has been selected for the mirror development phase because of their experience in the design and manufacturing of AlSi/NiP mirrors demonstrated in the development of the Earth Observation optical payload for small satellites (called STREEGO), based on an AlSi40 TMA telescope. The manufacturing process includes precision diamond turning, optical figuring and super-polishing. The optical coating will be done by Leonardo at their thin-films facility of Carsoli, Italy. Since the recipe prescribes to pre-heat the mirror surface at 100° C, Media Lario will qualify the mirror substrate with -25/+110°C thermal cycles to ensure adequate thermal stability for the coating process.
Acoustically actuated microbubbles in microchannels can be used as a versatile tool to directly manipulate fluids and particles in Lab-on-a-Chip devices for the purpose of fast microfluidic mixing, as well as the sorting of particles or cells based on their size and other physical properties. Many experimental investigations use such bubbles in microfluidic devices. However, the physics causing the streaming field are not understood in its details yet. Existing theoretical models describe the correlation of oscillating interfaces and the streaming field that they generate. The models are either based on the oscillation of rigid objects or interfaces that oscillate with simple oscillation modes. In the experiments of this work, much more complex oscillation modes were observed for an acoustically actuated sessile and hemi-cylindrical bubble in a microchannel. The bubble is resonantly driven at a frequency of 20 kHz, and periodic shape oscillations are recorded using a stroboscopic technique. With this technique, an equivalent frame rate of more than one million frames per second can easily be achieved without using high-speed imaging equipment. In contrast to the bubble interface, the motion of the surrounding fluid is not periodic and a stroboscopic technique cannot be applied. Therefore, a 256×256 pixel, high-speed imaging system at 180.000 frames per second is used to resolve the flow field by particle tracking velocimetry. The results of this work could help to revise current models for the shape oscillation of microbubbles in order to get a deeper understanding of the underlying physics. This could help to improve microfluidic applications that use acoustically actuated microbubbles as a tool for the manipulation of flows and particles in Lab-on-a-chip-devices.
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.
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.
KEYWORDS: Modulation transfer functions, Mirrors, Sensors, Tolerancing, Monte Carlo methods, Satellites, Astronomical imaging, Optical design, Space telescopes, Telescopes
A mid-to-high resolution optical payload, named STREEGO, featuring a compact envelope, reduced mass, and competitive cost has been designed to address Earth Observation applications from low Earth orbit (LEO) small satellites. STREEGO is a fully reflective telescope designed for operation at a nominal altitude of 600 km to provide a ground sampling distance (GSD) of 2.75 m, a field of view of about 1° and a modulation transfer function (MTF) greater than 10% at Nyquist frequency (91 cy/mm) with a telescope aperture of 200 mm. A large two-dimensional CMOS sensor with a pixel size of 5.5 μm has been selected in order to obtain the requested GSD with a focal length of 1.2 m, and a signal-to-noise ratio equal to 75. A demonstration model is in the detailed design phase and will be developed, with completion planned by end of 2015. We present a detailed description of the instrument, which, by leveraging on aspheric surfaces and light-weight solutions, achieves remarkable performance in terms of compactness and image quality with less than 25 kg in mass. The optical design is based on a three mirror anastigmat (TMA) configuration whereby the mirrors are realized in metal with the same coefficient of thermal expansion of the structure in order to obtain an athermal design.
The increasing number of Earth Observation missions launched over the last decade has stimulated the development of a large number of satellite instruments able to acquire and deliver rich imageries suitable to support many different applications. Recent advances in electronics, optical manufacturing and remote sensing are now enabling the conception of smaller instruments that could enable new mission concepts at lower costs such as the adoption of satellite constellations for improved temporal resolution. In this paper we present the development of an innovative optical payload named STREEGO suitable for Earth Observation from Low Earth Orbit (LEO) microsatellites. STREEGO is an athermal, fully reflective telescope based on a three mirror anastigmat (TMA) design which features a 200 mm aperture, a focal length of 1.2 m and an across-track Field of View (FoV) of about 2°. Leveraging on a large format two-dimensional CMOS sensor with a pixel size of 5.5 μm, it delivers a nominal modulation transfer function (MTF) of 64% at Nyquist frequency and a ground sampling distance of 2.75 m from an altitude of 600 km. In the design of the instrument detailed stray-light and tolerance analyses were performed and a worst-case thermal model was also developed to ensure that optimal image quality is achieved under operational conditions. After preliminary tests on a Demonstrator Model (DM), an Engineering Model (EM) of the payload with a mass of 20 kg including its electronics and mounting interfaces has been integrated and tested in laboratory and it is now ready to start an environmental test campaign to increase its Technology Readiness Level (TRL). The qualification of the instrument and the results achieved are presented in detail.
The BEaTriX (Beam Expander Testing X-ray facility) project is an X-ray apparatus under construction at INAF/OAB to
generate a broad (200´60 mm2), uniform and low-divergent X-ray beam within a small lab (6´15 m2). BEaTriX will
consist of an X-ray source in the focus a grazing incidence paraboloidal mirror to obtain a parallel beam, followed by a
crystal monochromation system and by an asymmetrically-cut diffracting crystal to perform the beam expansion to the
desired size. Once completed, BEaTriX will be used to directly perform the quality control of focusing modules of large
X-ray optics such as those for the ATHENA X-ray observatory, based on either Silicon Pore Optics (baseline) or Slumped
Glass Optics (alternative), and will thereby enable a direct quality control of angular resolution and effective area on a
number of mirror modules in a short time, in full X-ray illumination and without being affected by the finite distance of
the X-ray source. However, since the individual mirror modules for ATHENA will have an optical quality of 3-4 arcsec
HEW or better, BEaTriX is required to produce a broad beam with divergence below 1-2 arcsec, and sufficient flux to
quickly characterize the PSF of the module without being significantly affected by statistical uncertainties. Therefore, the
optical components of BEaTriX have to be selected and/or manufactured with excellent optical properties in order to
guarantee the final performance of the system. In this paper we report the final design of the facility and a detailed
performance simulation.
In the framework of an European Space Agency contract, Media Lario Technologies is developing an optical payload for Earth Observation targeted to small satellites. In this paper we present a detailed description of the imager which, by leveraging on aspheric surfaces, bonnet polishing, lightweight materials, an off-the-shelf large format CMOS detector and multispectral filters integrated in the FPA, achieves remarkable image quality with compact volume claim and mass of only 15 kg. The instrument is based on a three mirror anastigmat (TMA) design with an aperture of 200 mm and an F/number of 6. The payload is designed to provide a ground sampling distance (GSD) of 2.75 m for the panchromatic channel at a reference altitude of 600 km, a field of view of 1° and a nominal MTF greater than 60% at Nyquist frequency with a Signal to Noise Ratio (SNR) greater than 100.
A lightweight, single-aperture, and multispectral imaging system operating from visible to long wavelength infrared has been manufactured and tested based on an innovative three-mirror anastigmat optical design. The complex off-axis aspherical toroidal mirrors of the optics have been obtained by electroforming replication from masters having a shape opposite to the mirror shape and manufactured as stand-alone parts by using five-axis single-point diamond turning. The technology is extendible to full free-form optics without any process modification enabling affordability of complex optics since multiple identical copies of the mirrors can be produced from each master. Moreover, thin (∼1 mm ) electroformed mirrors keep the imaging system mass less than 3 kg . With an effective focal length of 136 mm, the system is suitable for airborne surveillance applications and provides a full aperture F/# of 1.4, a field of view of 4.3×3.1 deg , and a nominal contrast better than 75% in the visible waveband at 25 cycles/mm . A beam splitter can be accommodated to provide two separated channels for two or more spectral wavebands. Stray light and thermostructural design has been performed to comply with airborne applications. Experimental results demonstrate the feasibility of the technology, although process improvements are required to reach the extremely demanding theoretical performance of the optical design.
A lightweight single-aperture and multi-spectral sensor operating from Visible to LWIR has been designed, manufactured and tested exploiting a Three Mirror Anastigmat (TMA) telescope featuring thin free-form mirrors electroformed from negative masters. Manufacturing complexity is in place only for the master realization, the contribution of which to the sensor cost decreases with the number of replicas. The TMA, suitable for airborne surveillance applications, has F/no. 1.4, focal length 136 mm and field of view 4.3° × 3.1°, and provides two channels, in the MWIR-LWIR and in the visible waveband. The nominal contrast is better than 75% in the visible at 25 cycles/mm. Electroformed 1 mm thick mirrors keep the sensor mass below 3 kg. Stray light and thermo-structural design has been done to comply with airborne conditions.
A vertical Long Trace Profiler (LTP) has been developed to characterize profile slope and figure error of grazing
incidence aspherical X-ray mirrors with short radius of curvature (1 m - 5 m) and length up to 300 mm while achieving
more than 100 mrad-level dynamical range and acceptable value of measurement accuracy (< 10 μrad). The increase of the dynamical range is obtained by separating the optical path delivering the probe beam to the test surface from the light path reflected by the sample, and by using a movable collecting mirror to redirect it towards the detector. Experimental data acquired through the developed prototype on X-ray optics are compared with the profiles measured on the same samples through a more complex profiler (called MPR700) based on a high resolution distance measuring sensor, laser
interferometers and precise optical flats. The comparison between the two devices demonstrates the functionality of the proposed LTP scheme and shows the possibility to extend the field of applications of the LTPs avoiding the need of
more expensive measuring devices based on distance measuring sensors and optical references.
MPE will provide the X-ray Survey Telescope eROSITA for the Russian Spektrum-Roentgen-Gamma Mission to be
launched in 2013. It consists of a compact bundle of 7 co-aligned mirror modules with a focal length of 1600 mm and 54
nested mirror shells each. Therefore, its sensitivity in terms of effective area, field-of-view (61'), and angular resolution
(15" HEW on-axis) will yield a high grasp of about 1000 cm2 deg2 around 1 keV with an average angular resolution of
~26" HEW over the field-of-view (30" including optical and spacecraft error contributions). After an extended test
program on single mirror shells, assembled test modules (6 shells) and a qualification model we have now started
integration of flight mirror modules. We give a résumé on the development and test program including key
improvements to the shell integration method. Moreover, we report on the integration progress and present first results
on the X-ray performance of partially integrated mirror modules.
Media Lario Technologies (MLT), leveraging off its unique in-field collector experience, has designed the Grazing
Incidence Collector (GIC) for the Sn-fueled Discharge Produced Plasma (DPP) source developed by Philips Extreme UV
(PEUV) and XTREME technologies (XT) for High Volume Manufacturing (HVM) deployment. The performance of the
HVM GIC described in this work shows a point-source collection efficiency of 24%, and is enabled by an integrated
thermal control system designed to ensure optical stability for an absorbed thermal load of 6 kW. The GIC reflective
layer has been custom tailored to match the debris mitigation strategy developed and characterized by PEUV and XT,
supporting at least a 1-year lifetime proposition of the source-collector module.
Leveraging off the experience gained in GIC, MLT is developing the processes to manufacture the Normal Incidence
Collector (NIC) for Laser Produced Plasma (LPP) sources. Using its proprietary disruptive replication technology by
electroforming, MLT is developing thermal management designs for NIC enabling stable operation at room temperature.
This work reports on the performance of (symbol) 150 mm thermally managed NIC demonstrators. The mirror substrates have
been integrated with new proprietary thermal management designs that are well suited to the electroformed mirrors. We
also report on the reflectivity of the Mo/Si multilayer coated mirror, achieving maximum reflectivity values of 62% and
a center wavelength (FWHM) of 13.52 nm, which demonstrates acceptable performance in an LPP NIC application.
High throughput lightweight Hard X-ray Optics manufactured via electroforming replication process from supersmooth
mandrels are the primary candidate for some of future New Hard X-ray missions. Media Lario Technologies (MLT) is
the industrial enabler exploiting the electroforming technology initially applied for the ESA XMM-Newton mission and
further developed in cooperation with Brera Astronomical Observatory (INAF/OAB). The current and ongoing
development activities in Media Lario Technologies complement the electroforming technology with a suite of critical
manufacturing and assembly of the Mirror Module Unit. In this paper, the progress on mandrels manufacturing, mirror
shell replication, multilayer coating deposition, mirror module integration, and relevant metrology is reported in view of
the upcoming production phase. Mandrel production is a key point in terms of performances and schedule; the results
from of NiP prototype mandrels fabricated using a proprietary multistep surface finishing process are reported. The
progress in the replication of ultrathin Nickel and Nickel-Cobalt substrates gold coated mirror shells is reported together
with the results of MLT Magnetron Sputtering multilayer coating technology for the hard x-ray waveband and its
application to W/Si. Due to the criticality of low thickness mirror handling, the integration concept has been refined and
tested on prototype mechanical structures under full illumination UV vertical optical bench.
MPE will provide the X-ray Survey Telescope eROSITA [5] for the Russian Spektrum-Roentgen-Gamma Mission [4] to
be launched in 2011. The design of the X-ray mirror system is based on that of ABRIXAS: The bundle of 7 mirror
modules with the short focal length of 1600 mm makes it still a compact instrument while, however, its sensitivity in
terms of effective area, field-of-view, and angular resolution shall be largely enhanced with respect to ABRIXAS. The
number of nested mirror shells increases from 27 to 54 compared to ABRIXAS thus enhancing the effective area in the
soft band by a factor of six. The angular resolution is targeted to be 15 arc seconds half-energy width (HEW) on-axis
resulting in an average HEW of 26 arc seconds over the 61 arc minutes field-of-view (FoV). The instrument's high grasp
of about 1000 cm2deg2 in the soft spectral range and still 10 cm2deg2 at 10 keV combined with a survey duration of 4
years will generate a new rich database of X-ray sources over the whole sky. As the 7 mirror modules are co-aligned
eROSITA is also able to perform pointed observations.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.