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The General Court has confirmed that a sign reproduced in a small size and in arguably a concealed location on the packaging of the product is unlikely to be noticed by the relevant consumer and, as a result, does not prove use of the mark.

T-668/19, Ardagh Metal Beverage Holdings GmbH & Co KG v EUIPO, EU:T:2021:420 (not available in English), 7 July 2021 The General Court clarifies its approach to sound marks and Article 7(1)(b) of the EU Trade Mark Regulation 2017/1001 (EUTMR).

General Court, T-193/18, Andreas Stihl v EUIPO, EU:T:2021:163, 24 March 2021 In its first judgment since the decision of the Court of Justice of the European Union (‘CJEU’) in the Red Bull case (C-124/18 P), the General Court has clarified its approach to colour marks and Article 4 of the EU Trade Mark Regulation 2017/1001 (‘EUTMR’).

Court of Justice of the European Union, MINERAL MAGIC/MAGIC MINERALS BY JEROME ALEXANDER et al, C-809/18 P, EU: C:2020:902, 11/11/2020 The Court of Justice provides clear guidance on the test to be applied under Article 8(3) of the EU Trade Mark Regulation 2017/1001 (‘EUTMR).

For direct imaging of exoplanets, Scalar Vortex Coronagraphs (SVCs) are an attractive alternative to the popularly used Vector Vortex Coronagraphs (VVCs). This is primarily because they are able to induce the same phase ramp regardless of the incoming light's polarization state. We tested a set of stepped SVC staircase masks in the Exoplanet Technology Laboratory (ET Lab) at Caltech on the High-Contrast Spectroscopy Testbed (HCST). Here we present some preliminary findings of their starlight suppression ability, achieving raw contrasts on the order of 1e-5 for 7 to 9 lambda/D. We also characterized their chromatic performance and performed wavefront control to achieve preliminary contrasts on the order of 1e-7 with EFC. These initial experimental results with SVCs have shown scalar vortex technology has a great potential for future exoplanet direct imaging missions., Comment: SPIE Optics + Photonics 2021

Diffraction and reflection from the optical edges is the dominant source of stray light from a starshade. However, recent progress in optical edge design has led to much reduced predictions in this source. Secondary sources now also play a role; these sources arise from two or more reflections from the starshade structure. These multiple reflections allow light to reach the telescope from parts of the structure that are shaded from direct sunlight. Here we analyze the secondary sources for the starshade model developed as part of the S5 technology development and show the effects of optical edge mechanical design variants and mitigations.

General Court of the European Union, Case T-573/18 FORM EINES SCHNÜRSENKELS (3D), EU:T:2020:32, 5 February 2020

Court of Justice of the European Union, EUIPO v Wajos GmbH, C-783/18 P, EU:C:2019:1073, 12 December 2019 By a judgment rendered on 12 December 2019, the Court of Justice of the European Union dismissed the appeal filed by the European Union Intellectual Property Office (EUIPO) against a judgment of the General Court allowing the registration of a bottle taking the shape of an amphora.

ZrO2-reinforced high alloy steels have a strong tendency for pore formation during thermal joining and are therefore considered as non-weldable. However, present investigations have shown that it is possible to join particle-reinforced steels by a dissimilar electron beam braze-welding with a beam offset. The joints were characterised by light optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods, such as electron backscatter diffraction (EBSD), energy dispersive X-ray spectroscopy (EDS) and selected area electron diffraction (SAED). The mechanical properties and the deformation behaviour of the welded material were studied in tensile tests. The quality and type of the joints depend on the dilution of the weld. The welds with a level of dilution between 2 and 10% are free of defects and show an epitaxial growth onto the base material which yields superior mechanical properties compared to the welds without dilution. The welds produced by electron beam brazing exhibited the formation of oxide films which prevented an epitaxial growth of the solidified material. Therefore, a significant impact on the results of the tensile tests was noticed.

Starshade in formation flight with a space telescope is a rapidly maturing technology that would enable imaging and spectral characterization of small planets orbiting nearby stars in the not-too-distant future. While performance models of starshade-assisted exoplanet imaging have been developed and used to design future missions, their results have not been verified from the analyses of synthetic images. Following a rich history of using community data challenges to evaluate image-processing capabilities in astronomy and exoplanet fields, the Starshade Technology Development to TRL5 (S5), a focused technology development activity managed by the NASA Exoplanet Exploration Program, is organizing and implementing a starshade exoplanet data challenge. The purpose of the data challenge is to validate the flow down of requirements from science to key instrument performance parameters and to quantify the required accuracy of noisy background calibration with synthetic images. This data challenge distinguishes itself from past efforts in the exoplanet field in that (1) it focuses on the detection and spectral characterization of small planets in the habitable zones of nearby stars, and (2) it develops synthetic images that simultaneously include multiple background noise terms—some observations specific to starshade—including residual starlight, solar glint, exozodiacal light, detector noise, as well as variability resulting from starshade’s motion and telescope jitter. We provide an overview of the design and rationale of the data challenge. Working with data challenge participants, we expect to achieve improved understanding of the noise budget and background calibration in starshade-assisted exoplanet observations in the context of both starshade rendezvous with Roman and Habitable Exoplanet Observatory. This activity will thus help NASA prioritize further technology developments and prepare the science community for analyzing starshade exoplanet observations.

High-contrast imaging enabled by a starshade in formation flight with a space telescope can provide a near-term pathway to search for and characterize temperate and small planets of nearby stars. NASA's Starshade Technology Development Activity to TRL5 (S5) is rapidly maturing the required technologies to the point at which starshades could be integrated into potential future missions. Here we reappraise the noise budget of starshade-enabled exoplanet imaging to incorporate the experimentally demonstrated optical performance of the starshade and its optical edge. Our analyses of stray light sources - including the leakage through micrometeoroid damage and the reflection of bright celestial bodies - indicate that sunlight scattered by the optical edge (i.e., the solar glint) is by far the dominant stray light. With telescope and observation parameters that approximately correspond to Starshade Rendezvous with Roman and HabEx, we find that the dominating noise source would be exozodiacal light for characterizing a temperate and Earth-sized planet around Sun-like and earlier stars and the solar glint for later-type stars. Further reducing the brightness of solar glint by a factor of 10 with a coating would prevent it from becoming the dominant noise for both Roman and HabEx. With an instrument contrast of 1E-10, the residual starlight is not a dominant noise; and increasing the contrast level by a factor 10 would not lead to any appreciable change in the expected science performance. If unbiased calibration of the background to the photon-noise limit can be achieved, Starshade Rendezvous with Roman could provide nearly photon-limited spectroscopy of temperate and Earth-sized planets of F, G, and K stars, Accepted for publication in the Journal of Astronomical Telescopes, Instruments, and Systems (JATIS)

A starshade is a large flower-shaped screen designed to enable the direct imaging of exoplanets with a space telescope. The starshade perimeter is composed of sharp, precisely shaped edges to minimize the glint of sunlight into the telescope. Past work has focused on bare edges to minimize the terminal radius. This paper describes the broadband, wide-angle performance of edges coated with a thin multi-layer anti-reflection coating. This coating uses a combination of interference and absorption to reduce the surface reflectivity and to avoid the negative effects associated with a large cross-sectional area. A custom scattered light testbed has been developed to quantify the amount of light scattered from sample edges and to validate Finite-Difference Time-Domain (FDTD) models of the optical scatter. We show that optical edge samples with this coating significantly reduce the solar glint pattern compared to similar uncoated optical edges.

The National Academies’ Decadal Survey telescope studies have produced mission design concepts that plot pathways into the future to follow on from Hubble, Spitzer, JWST and NGRST. Considering the results of the LUVOIR and HabEx studies in particular, it is clear that segmented mirrors will eventually be needed to provide very large apertures in space and that this architecture presents both a scientific opportunity and an engineering challenge. Furthermore, while HabEx and LUVOIR cover a great deal of spectrum, both fall short of the mid-IR region where general astronomy and astrophysics can be undertaken that would be impossible from terrestrial observatories and where there also exist spectral features of interest in the search for life. A telescope with similar capabilities to Habex/LUVOIR but also capable of exoplanet work in spectral regions up to 5 μm would largely bridge the gap between those proposals and TPF-I (which would have operated from about 7 μm upwards), and is therefore worthy of study. The Active Telescope for Space Astronomy (ATSA) design study presents a possible architecture and is moderately sized (6 m) to enable the use of both starshade and coronagraph technologies. While the segment gaps of a segmented primary mirror present a challenge for coronagraphy, the architecture does allow direct wavefront control at each segment of that mirror, enabling a great degree of control at the primary source of contrast degradation. While active systems (for example, deformable mirrors on WFIRST CGI) are being incorporated into telescope designs today, a fully active mirror system needs further development for a future mission. With this concept in mind, and intending to build on the LUVOIR and HabEx studies, we discuss the elements of a cooled telescope design enabling both general astrophysics and exoplanet studies from the near UV through to the near-IR.

Interferometry can reach high resolution not only with separated apertures, but also across a single telescope aperture. Indeed, as shown by the Palomar Fiber Nuller (PFN), cross-aperture nulling interferometry can detect companions at much smaller angular offsets from stars than coronagraphy on the same telescope can reach. In particular, the PFN was able to detect the faint secondary companion of the spectroscopic binary η Peg at roughly a third of the telescope’s diffraction beamwidth, with null depth accuracies of several 10-4, while also demonstrating the use of baseline rotation to detect companions, as originally envisioned for space-based nullers. Cross-aperture nulling observations can thus resolve separations well inside the central core of a telescope’s diffraction beam. Here we summarize the lessons learned from the PFN’s demonstration experiments, as well as from larger mid-infrared nullers, pointing toward potential performance improvements that could enable a variety of nulling-based exoplanet and dust observations interior to the coronagraphic regime on larger telescopes. Two interesting new developments are the grating nuller, in which both beam combination and phase shifting are provided by the same optical element, and the vortex fiber nuller, which straddles the coronagraphic and separated-subaperture interferometric regimes.

The Habitable-Zone Exoplanet Observatory Mission (HabEx) is one of four large missions under review for the 2020 astrophysics decadal survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone around nearby Sun-like stars. In addition, HabEx will perform a broad range of general astrophysics science enabled by a 115- to 1700-nm spectral range and 3 × 3 arcminute field of view. Critical to achieving its science goals, HabEx requires a large, ultrastable UV/optical/near-IR telescope. Using science-driven systems engineering, HabEx specified its baseline telescope to be a 4-m off-axis, unobscured three-mirror anastigmatic architecture with diffraction-limited performance at 400 nm, and wavefront stability on the order of a few tens of picometers. We summarize the systems-engineering approach to the baseline telescope assembly’s optomechanical design, including a discussion of how science requirements drive the telescope’s specifications. We also present structural thermal optical performance analysis showing that the baseline telescope structure meets its specified tolerances. We report new and updated analysis that is not in the HabEx final report.

The National Academies' 2020 Decadal Survey on Astronomy and Astrophysics will provide a broad vision for future science in these disciplines and the Habitable Exoplanet Observatory (HabEx) is one of four major observatory missions extensively studied in preparation for the survey. HabEx is a space telescope with a 4 m diameter primary mirror, carrying a complement of two general astrophysics camera/spectrographs with coverage from the far UV to the near infrared as well as two key instruments for exoplanet science. These exoplanet instruments consist of a high performance coronagraph (that places stringent demands on the overall observatory design and performance) and a remote (tens of megameters distant) formation flying occulter, consisting of a 52 m diameter starshade deployed from a second launch vehicle. This paper discusses the specific features of the observatory that permit high contrast coronagraphy at the 10−10 contrast level and the design considerations for the coronagraph itself. The starshade design is discussed in the context of the current technology development activities being undertaken by NASA to bring starshade readiness up to TRL5.

Background High-intensity interval training (HIIT) is an important training component to improve aerobic and anaerobic exercise capacity. Higher HIIT workloads in general may generate additional effects on the improvement of exercise capacity, while missing adherence to more strenuous training regimes may affect training success. This study investigated if higher training workload generated by progressive HIIT (proHIIT) is superior to HIIT when used in an uncontrolled setting. Methods Thirty-four moderately trained females and males performed a 4-week training intervention with three exercise sessions per week. Participants were randomized into two HIIT groups using the individual lactate threshold at baseline: Group 1 (N.=17), HIIT, four runs at maximal speed (all-out) with 30 s active recovery (total: 48 runs), Group 2 (N.=17), proHIIT, 4 runs at maximal speed (all-out) with 30-second active recovery with one extra repetition every week (up to seven runs, for a total of 66 runs). An incremental field test protocol with standard blood lactate (LA) diagnostic and heart rate monitoring was used to access changes in exercise capacity. Results Overall, power output (running speed) at LA threshold (baseline LA+1.5 mmol/L) increased by +3.6% (P=0.004, effect size [ES] 0.38) after 4 weeks of HIIT. However, no significant between-group differences pre- vs post-intervention were detected. Conclusions Our data suggest that proHIIT does not provide additional improvement of running speed at individual lactate threshold over HIIT in an uncontrolled setting.

We report on an investigation using ultrafast laser inscription in borosilicate glasses to create in-volume phase optics. An application of an optic fashioned in this way is discussed in the context of broadband “scalar vortex coronagraphy” for astronomical imaging.

The HabEx mission concept is intended to directly image planetary systems around nearby stars, and to perform a wide range of general astrophysics and solar system observations. The baseline HabEx design would use both a coronagraph and a starshade for exoplanet discovery and characterization. We describe a lower-cost alternative HabEx mission design, which would only use a starshade for exoplanet science. The starshade would provide excellent exoplanet science performance, but for a smaller number of detected exoplanets of all types, including exoEarth candidates, and a smaller fraction of exoplanets with measured orbits. The full suite of HabEx general astrophysics and solar-system science would be supported.

A starshade enables direct imaging of Earth-like exoplanets in the habitable zone of nearby stars by suppressing light from a target star so that orbiting planets are revealed. The perimeter of a starshade, known as the optical edge, has two critical functions. First, it must meet a precise in-plane profile specification to form a deep shadow in which the telescope is placed. Second, it must minimize reflected sunlight, as scattered sunlight significantly degrades the achievable contrast. Prior work on small scales and in a laboratory environment has shown that these requirements can be met using a chemically etched amorphous metal foil. This paper describes the next step of development, a first ever demonstration of assembled optical edge segments that meet both requirements simultaneously. The segments were constructed using space-compatible components and tested to relevant thermal and mechanical environments. A thorough assessment of edge performance, including in-plane profile, sunlight scatter and mechanical survivability was performed both before and after environmental testing. Furthermore, a custom scattered light testbed has been developed to quantify the magnitude of scattered sunlight over the entire length of the optical edge. The results of this study inform the future development of optical edge technology and pave the way towards eventual flight implementation.

The HabEx study has developed a baseline concept for a 4 m aperture next generation space telescope operating from the ultraviolet to the infrared, capable of compelling general astrophysics and exoplanet science. HabEx carries four instruments, a UV spectrometer/imager (UVS) together with a general purpose astrophysics camera/spectrograph (HWC) and for exoplanet work, a coronagraph and a starshade. UVS reaches down to 115 nm with resolution up to 60,000 and a 3’x3’ field of view. HWC operates between 370 nm and 1800 nm, again with a 3’x3’ field of view; the spectral resolution is 1000 and it carries a suite of science filters. The telescope is capable of tracking both deep space and solar system objects. The coronagraph enables observations and spectroscopy at up to R=140 with instantaneous 20% bandwidth between wavelengths of 450 and 1800 nm and is intended to be used in a survey mode. However, it also backs up most of the functionality of the accompanying starshade instrument which will have superior performance for spectroscopy. The 52 m diameter starshade flies 76,600 km from the telescope and at that range has a broadband suppression of the starlight between 300 and 1000 nm. A single observation at 108% bandwidth covers a very wide spectral band at a resolution up to 140. Both coronagraph and starshade are equipped with integral field spectrometers to enable simultaneous spectroscopy of exoplanets within the field of view. This paper details the design of the telescope, the four science instruments and associated optical systems.

The Habitable Exoplanet Observatory Mission (HabEx) is one of four missions under study for the 2020 Astrophysics Decadal Survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone around nearby sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 100 to 2500 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving its the HabEx science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is a 4-meter off-axis unobscured three-mirror-anastigmatic, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. This paper summarizes the opto-mechanical design of the HabEx baseline optical telescope assembly, including a discussion of how science requirements drive the telescope’s specifications, and presents analysis that the baseline telescope structure meets its specified tolerances.

A sunflower-like starshade positioned between an exoplanet host star and a telescope forms a deep shadow at the telescope enabling the faint exoplanet to be viewed without being overwhelmed by veiling glare from the star. The starshade perimeter has hundreds of meters of sharp edge that are directly exposed to sunlight. The sunlight diffracts and reflects from the edge resulting in a glint pattern that can be brighter than the exoplanet. We have developed models of the edge glint to explain laboratory measurements, to guide the development of edges with minimum glint, and to determine the fundamental glint floor which is set by diffraction. The models include finite difference time domain calculations, Sommerfeld's half-plane diffraction expressions, and a micro-facet scattering model. Models successfully reproduce the features and magnitude of the measured polarization-dependent scatter and show that measured edges are performing near the theoretical limit.

The Habitable Exoplanet Observatory (HabEx) is one of four large mission studies commissioned by NASA for the 2020 Decadal Survey in Astrophysics. HabEx has identified three driving science goals: 1) to seek out nearby worlds and explore their habitability, 2) to map out nearby planetary systems and underst the diversity of the worlds they contain, and 3) to enable new explorations of astrophysical systems from our solar system to galaxies and the universe by extending our reach in the UV through near-IR To achieve these goals, the HabEx study has baselined a space telescope at Sun-Earth L2, with a 4 m aperture and four science instruments - a coronagraph, a starshade, a high resolution UV spectrograph, and a multi-purpose, wide-field camera. The second part of the observatory is an external starshade occulter of 52 m diameter. To achieve the precision and stability required for the coronagraph to image earth-sized exoplanets to better than 10−10 contrast, the telescope flight system is equipped with a vector vortex coronagraph and colloidal electrospray microthrusters. The telescope takes advantage of the mass and volume launch capability of NASA's SLS Block 1 B delivery system with a separate launch for the starshade on a smaller vehicle. In this paper, we provide an overview of the HabEx telescope flight system that would advance astrophysical science in the same spirit as the Hubble Space Telescope well into this century.

Starshade missions offer a near-term capability to measure the spectra of Earth-sized exoplanets, searching for possible bio-indicators. To function, a starshade and telescope separated by approximately 50 Mm must align to the meter-level on the line to the target star. From the telescope׳s perspective, this alignment in turn requires sensing the bearing between target star and starshade to approximately 1 milli-arcsecond (5 nrad). Previously, several fine bearing sensors have been proposed based on pupil images of the starshade׳s shadow. In this paper, a fine bearing sensor is presented based on measuring in the focal plane the bearing between a laser beacon on the starshade and the diffracted centroid of the target star that “leaks” around the starshade outside the science wavelengths. Coarse and medium bearing sensors are also introduced that allow for autonomous operation. The performance of extended Kalman filters using the bearing sensors is presented, as well as deadbanding performance in science mode.

Several starshade concepts for imaging exo-Earths would operate at the second Earth–Sun Lagrange point (L2) and consist of a starshade flying in formation tens to hundreds of thousands of kilometers from a telescope. The starshade would need to maintain meter-level lateral alignment with the line of sight from telescope to target star. A companion paper describes an optical sensing scheme using a pupil imaging camera in the telescope that can sense the relative lateral position to a few centimeters. A full flight-traceable formation flying framework that leverages this sensor is presented. In particular, a two-dimensional “disk deadbanding” algorithm is introduced for lateral control. The framework also maximizes the drift time between thruster burns to reduce interruption to scientific observations. The main sources of uncertainty affecting the control performance are compared, and it is found that spacecraft mass uncertainty is a driving factor. The formation flying environment is also analyzed to identify conditions that lead to worst-case differential gravity and solar radiation pressure disturbances. Finally, for a representative observation scenario with the Wide Field Infrared Space Telescope, this control system is tested through Monte Carlo simulations. The results show robust meter-level control with essentially optimal drift time between thruster burns.

A key challenge for starshades is formation flying. To successfully image exoplanets, the telescope boresight and starshade must be aligned to ∼1 m at separations of tens of thousands of kilometers. This challenge has two parts: first, the relative position of the starshade with respect to the telescope must be sensed; second, sensor measurements must be combined with a control law to keep the two spacecraft aligned in the presence of gravitational and other disturbances. In this work, we present an optical sensing approach using a pupil imaging camera in a 2.4-m telescope that can measure the relative spacecraft bearing to a few centimeters in 1 s, much faster than any relevant dynamical disturbances. A companion paper will describe how this sensor can be combined with a control law to keep the two spacecraft aligned with minimal interruptions to science observations.

The HabEx (Habitable Exoplanet) space telescope mission concept carries two complementary optical systems as part of its baseline design, a coronagraph and a starshade, that are designed to detect and characterize planetary systems around nearby stars. The starshade is an external occulter which would be 72 m in diameter and fly some 124,000 km ahead of the telescope. A starshade instrument on board the telescope enables formation flying to maintain the starshade within 1 m of the line of sight to the star. The starshade instrument has various modes, including imaging from the near UV through to the near infrared and integral field spectroscopy in the visible band. The coronagraph would provide imaging and integral field spectroscopy in the visible band and would reach out to 1800 nm for low resolution spectroscopy in the near infrared. To provide the necessary stability for the coronagraph, the telescope would be equipped with a laser metrology system allowing measurement and control of the relative positions of the principal mirrors. In addition, a fine guidance sensor is needed for precision attitude control. The requirements for telescope stability for coronagraphy are discussed. The design and requirements on the starshade will also be discussed.

The Habitable Exoplanet Imaging Mission (HabEx) Study is one of four studies sponsored by NASA for consideration by the 2020 Decadal Survey Committee as a potential flagship astrophysics mission. A primary science directive of HabEx would be to image and characterize potential habitable exoplanets around nearby stars. As such, the baseline design of the HabEx observatory includes two complimentary starlight suppression systems that reveal the reflected light from the exoplanet – an internal coronagraph instrument, and an external, formation-flying starshade occulter. In addition, two general astrophysics instruments are baselined: a high-resolution ultraviolet spectrograph, and an ultraviolet, visible, and near-infrared (UV/Vis/NIR), multi-purpose, wide-field imaging camera and spectrograph. In this paper, we present the baseline architecture concept for a 4m HabEx telescope, including key requirements and a description of the mission and payload designs.

The HabEx (Habitable Exoplanet) concept study is defining a future space telescope with the primary mission of detecting and characterizing planetary systems around nearby stars. The telescope baseline design includes a high-contrast coronagraph and a starshade to enable the direct optical detection of exoplanets as close as 70 mas to their star. In addition to the study of exoplanets, HabEx carries two dedicated instruments for general astrophysics. The first instrument is a camera enabling imaging on a 3 arc minute field of view in two bands stretching from the UV at 150 nm to the near infrared at 1800 nm. The same instrument can also be operated as a multi-object spectrograph, with resolution of 2000. The second instrument is a high-resolution UV spectrograph operating from 300 nm down to 115 nm with up to 60,0000 resolution. HabEx would provide the highest resolution UV/optical images ever obtained. Diffraction limited at 0.4 μm, it would outperform all current and approved facilities, including the 30 m class ground-based extremely large telescopes (ELTs), which will achieve ~0.01 arcsecond resolution at near-infrared (IR) wavelengths with adaptive optics, but will be seeing-limited at optical wavelengths. HabEx would observe wavelengths inaccessible from the ground, including the UV and in optical/near-IR atmospheric absorption bands. Operating at L2, far above the Earth’s atmosphere and free from the large thermal swings inherent to HST’s low-Earth orbit, HabEx would provide an ultra-stable platform that will enable science ranging from precision astrometry to the most sensitive weak lensing maps ever obtained. Here we discuss the design concepts of the general astrophysics optical instruments for the proposed observatory.

The HabEx mission concept is intended to directly image planetary systems around nearby stars, and to perform a wide range of general astrophysics and solar system observations. Its main goal is the discovery and characterization of Earthlike exoplanets through high-contrast imaging and spectroscopy. The baseline HabEx concept would use both a coronagraph and a starshade for exoplanet science. We describe an alternative, “HabEx Lite” concept, which would use a starshade (only) for exoplanet science. The benefit is lower cost: by deleting the complex coronagraph instrument; by lowering observatory mass; by relaxing tolerances and stability requirements; by permitting use of a compact on-axis telescope design; by use of a smaller launch vehicle. The scientific penalty of this lower cost option is a smaller number of detected exoplanets of all types, including exoEarth candidates, and a smaller fraction of exoplanets with measured orbits. Our approach uses a non-deployed segmented primary mirror, whose manufacture is within current capabilities.

The HabEx (Habitable Exoplanet Imaging Mission) study is developing concepts for a next generation space telescope operating from the ultraviolet to the infrared. HabEx is making exoplanet science the primary mission objective and adding two secondary payload instruments for general astrophysics, including ultraviolet spectroscopy. For exoplanet work, two approaches are being developed. The first is a coronagraph with two separate channels to cover a broad spectral range from 450 nm to 1000 nm in two observations. The second is a starshade to cover the band 300 nm to 1000 nm in a single observation. These instruments are complementary; the coronagraph can make rapid survey observations while the starshade can reach closer in to the star and once on target, enables more efficient spectroscopic observations. This paper describes some of the key design considerations necessary to enable coronagraph and starshade observations.

Case T-569/18, Kordes' Rose Monique, General Court of the European Union, decision of 18 June 2019, EU:T:2019:421

We directly show how impurity atoms induce the condensation of a representative electronic phase, the charge density wave (CDW) phase, in atomic scale with scanning tunneling microscopy. Oxygen impurity atoms on the self-assembled metallic atomic wire array on a silicon crystal condense the CDW locally above the pristine transition temperature. More interestingly, the CDW along the wires is induced not by a single atomic impurity but by the cooperation of multiple impurities. First-principles calculations disclose the mechanism of the cooperation as the coherent superposition of the local lattice strain induced by impurities, stressing the coupled electronic and lattice degrees of freedom for the CDW. This opens the possibility of the strain engineering over electronic phases of atomic-scale systems.

Well-ordered stepped semiconductor surfaces attract intense attention owing to the regular arrangements of their atomic steps that makes them perfect templates for the growth of one-dimensional systems, e.g., nanowires. Here, we report on the atomic structure of the vicinal $\mathrm{Si}(111)$ surface with ${10}^{\ensuremath{\circ}}$ miscut investigated by a joint frequency-modulation scanning force microscopy (FM-SFM) and ab initio approach. This popular stepped surface contains $7\ifmmode\times\else\texttimes\fi{}7$-reconstructed terraces oriented along the $\mathrm{Si}(111)$ direction, separated by a stepped region. Recently, the atomic structure of this triple step based on scanning tunneling microscopy (STM) images has been subject of debate. Unlike STM, SFM atomic resolution capability arises from chemical bonding of the tip apex with the surface atoms. Thus, for surfaces with a corrugated density of states such as semiconductors, SFM provides complementary information to STM and partially removes the dependency of the topography on the electronic structure. Our FM-SFM images with unprecedented spatial resolution on steps coincide with the model based on a $(7\phantom{\rule{4pt}{0ex}}7\phantom{\rule{4pt}{0ex}}10)$ orientation of the surface and reveal structural details of this surface. Two different FM-SFM contrasts together with density functional theory calculations explain the presence of defects, buckling, and filling asymmetries on the surface. Our results evidence the important role of charge transfers between adatoms, restatoms, and dimers in the stabilisation of the structure of the vicinal surface.

We have worked to define the compelling next generation General Astrophysics science that the 4m implementation of the HabEx mission concept might enable. These science drivers have been used to define requirements for a far ultraviolet (FUV) spectrograph design for the telescope design that meets the needs of these programs. We describe both the drivers and the baseline design for the instrument, the modes it might support, and the choices that were made to optimize the performance. The operational performance of the instrument in cooperation with the rest of the telescope design is also discussed.

The HabEx study is defining a concept for a new space telescope with the primary mission of detecting and characterizing planetary systems around nearby stars. The telescope is designed specifically to operate with both a high contrast coronagraph and a starshade, enabling the direct optical detection of exoplanets as close as 70 mas from their star. The telescope will be equipped with cameras for exoplanetary system imaging and with spectrometers capable of characterizing exoplanet atmospheres. Gases such as oxygen, carbon dioxide, water vapor and methane have spectral lines in the visible and near infrared part of the spectrum and may indicate biological activity. In addition to the study of exoplanets, HabEx enables general astrophysics with two dedicated instruments. One instrument is a camera enabling imaging on a 3 arc minute field of view in two bands stretching from the UV to the near infrared. The same instrument can also be operated as a multi-object spectrograph, with resolution of 2000. A second instrument will be a high resolution UV spectrograph operating from 120 nm with up to 60,0000 resolution. We discuss the preliminary designs of the telescope and the optical instruments for the observatory.

Starshades, large occulters positioned tens of thousands of kilometers in front of space telescopes, offer one of the few paths to imaging and characterizing Earth-like extrasolar planets. However, for a starshade to generate a sufficiently dark shadow on the telescope, the two must be coaligned to just 1 meter laterally, even at these large separations. The principal challenge to achieving this level of control is in determining the position of the starshade with respect to the space telescope. In this paper, we present numerical simulations and laboratory results demonstrating that a Zernike wavefront sensor coupled to a WFIRST-type telescope is able to deliver the stationkeeping precision required, by measuring light outside of the science wavelengths. The sensor can determine the starshade lateral position to centimeter level in seconds of open shutter time for stars brighter than eighth magnitude, with a capture range of 10 meters. We discuss the potential for fast (ms) tip/tilt pointing control at the milli-arcsecond level by illuminating the sensor with a laser mounted on the starshade. Finally, we present early laboratory results.

The use of a starshade is one technique to perform high contrast imaging with space-based telescopes. The primary function of a starshade is to suppress light from a target star in order to image its orbiting planets. In order to provide the proper apodization function the edges of the starshade must follow a precise in-plane profile. However of equal importance is the issue of light from our own sun scattering off of the edges and entering the telescope. A method to alleviate this problem is to make the edges extremely sharp (< 1 μm terminal radius) such that the area available for scattering is minimized. The combination of these two requirements, along with the need to integrate the edges into a 30-40 m dia. deployable structure, present a number of significant engineering challenges. Substrate etching techniques are used to obtain both the intended profile as well as the edge sharpness. Current efforts implement an isotropic etching process on thin metal substrates. This paper discusses the progress towards producing a sharp optical edge at the coupon level. Samples have been characterized using scanning electron microscopy as well as a custom testbed to assess their scattered-light performance.

Exo-S is a probe-class mission study that includes the Dedicated mission, a 30 m starshade co-launched with a 1.1 m commercial telescope in an Earth-leading deep-space orbit, and the Rendezvous mission, a 34 m starshade intended to work with a 2.4 m telescope in an Earth-Sun L2 orbit. A third design, referred to as the Rendezvous Earth Finder mission, is based on a 40 m starshade and is currently under study. This paper presents error budgets for the detection of Earth-like planets with each of these missions. The budgets include manufacture and deployment tolerances, the allowed thermal fluctuations and dynamic motions, formation flying alignment requirements, surface and edge reflectivity requirements, and the allowed transmission due to micrometeoroid damage.