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This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies., Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb293

The far-infrared imager and polarimeter (FIP) for the Origins Space Telescope (Origins) is a basic far-infrared imager and polarimeter. The camera will deliver continuum images and polarization measurements at 50 and 250 μm. Currently available detector technologies provide sufficient sensitivity for background limited observations from space, at least on a single pixel basis. FIP incorporates large next-generation superconducting detector arrays and our technology development plan will push the pixel numbers for the arrays to the required size of 8000. Two superconducting detector technologies are currently candidates for the instrument: transition edge sensors or microwave kinetic inductance devices. Using these detectors and taking advantage of the cryogenic telescope that is provided by Origins, FIP will achieve mapping speeds of up to eight orders of magnitude faster than what has been achieved by existing observatories. The science drivers for FIP include observations of solar system objects, dust properties, and magnetic field studies of the nearby interstellar medium, and large scale galaxy surveys to better constrain the star formation history of the universe to address one of the main themes of Origins: “How does the Universe work?” In addition to the science, the FIP instrument plays a critical functional role in aligning the mirrors during on orbit observatory commissioning.

Optical designs for the next generation space science instruments call for unconventional, aspheric, and freeform (FF), prescriptions with tight tolerances. These advanced surfaces enable superior-performance, compact, and lower cost systems but are more challenging to characterize and, hence, to fabricate and integrate. A method was developed to characterize a wide range of optical surfaces, without requiring custom-made correctors, and to align them to each other for a high-performance optical system. A precision coordinate measuring machine, equipped with a non-contact, chromatic confocal probe, was used to measure numerous optics including large convex conics, high-sloped aspherics, several FF surfaces, and grazing-incidence x-ray optics. The resulting data were successfully reduced using custom-developed, advanced surface fitting analysis tool, to determine the optic’s alignment relative to the global and local coordinate systems, surface departure from design, and the as-built optical prescription. This information guided the modeling and the alignment of the corresponding as-built optical systems, including a flight system composed of a three-mirror anastigmat.

Our paper discusses the optical design of the Origins Space Telescope. Origins is one of four large missions under study in preparation for the 2020 Decadal Survey in Astronomy and Astrophysics. Sensitive to the mid- and far-infrared spectrum (between 2.8 and 588 μm), Origins sets out to answer a number of important scientific questions by addressing NASA’s three key science goals in astrophysics. The Origins telescope operates at f / 14. The design includes a 5.9-m-diameter primary mirror. The large on-axis primary consists of 18 “keystone” segments of two different prescriptions arranged in two annuli (six inner and twelve outer segments) that together form a circular aperture in the goal of achieving a symmetric point spread function. To accommodate the 46 × 15 arc min full field of view (FOV) of the telescope at the design wavelength of λ = 30 μm, a three-mirror anastigmat configuration is used. The design is diffraction-limited across its instruments’ FOV. A brief discussion of each of the three baselined instruments within the Instrument Accommodation Module is presented: (1) Origins Survey Spectrometer, (2) Mid-infrared Spectrometer, Camera transit spectrometer channel, and (3) Far-Infrared Polarimeter/Imager. In addition, the upscope options for the observatory are laid out as well including a fourth instrument: the Heterodyne Receiver for Origins.

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural background-limited sensitivity.

International audience; The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? We describe how Origins was designed to answer these alluring questions. We discuss the key decisions taken by the Origins mission concept study team, the rationale for those choices, and how they led through an exploratory design process to the Origins baseline mission concept. To understand the concept solution space, we studied two distinct mission concepts and descoped the second concept, aiming to maximize science per dollar and hit a self-imposed cost target. We report on the study approach and describe the concept evolution. The resulting baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. The chosen architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch. The cryo-thermal system design leverages James Webb Space Telescope technology and experience.

The Laser Interferometer Space Antenna (LISA) mission is a space-based gravitational wave detector consisting of three spacecraft with two transceiver telescopes per spacecraft. In addition to tight wavefront error control as expected for an interferometric system, there are tight pupil imaging and optical path length specifications. We use concepts gleaned from pupil aberration theory to understand these latter two constraints and show how these concepts led to a successful design for the LISA transceiver.

We present the results and methods of a survey of the four-mirror freeform imager solution space. This survey is a grid search over the parameters that remain after reducing the solution space’s degrees of freedom using first-, second-, and third-order aberration theory. We then optimize the systems’ higher-order surface shapes through sixth-order. Finally, we discuss general trends in the systems’ performance versus volume and etendue and their utility in trade studies.

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of Herschel, the largest telescope flown in space to date. After a 3 ½ year study, the Origins Science and Technology Definition Team will recommend to the Decadal Survey a concept for Origins with a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (MISC-T) will measure the spectra of transiting exoplanets in the 2.8 – 20 μm wavelength range and offer unprecedented sensitivity, enabling definitive biosignature detections. The Far-IR Imager Polarimeter (FIP) will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer (OSS) will cover wavelengths from 25 – 588 μm, make wide-area and deep spectroscopic surveys with spectral resolving power R ~ 300, and pointed observations at R ~ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The telescope has a Spitzer-like architecture and requires very few deployments after launch. The cryo-thermal system design leverages JWST technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural backgroundlimited sensitivity.

This paper discusses the optical design of the Origins Space Telescope. Origins is one of four large missions under study in preparation for the 2020 Decadal Survey in Astronomy and Astrophysics. Sensitive to the mid- and far-infrared spectrum (between 2.8 and 588 μm), Origins sets out to answer a number of important scientific questions by addressing NASA’s three key science goals in astrophysics. The Origins telescope has a 5.9 m diameter primary mirror and operates at f/14. The large on-axis primary consists of 18 ‘keystone’ segments of two different prescriptions arranged in two annuli (six inner and twelve outer segments) that together form a circular aperture in the goal of achieving a symmetric point spread function. To accommodate the 46 x 15 arcminute full field of view of the telescope at the design wavelength of λ = 30 μm, a three-mirror anastigmat configuration is used. The design is diffraction-limited across its instruments’ fields of view. A brief discussion of each of the three baselined instruments within the Instrument Accommodation Module (IAM) is presented: 1) Origins Survey Spectrometer (OSS), 2) Mid-infrared Spectrometer, Camera (MISC) transit spectrometer channel, and 3) Far-Infrared Polarimeter/Imager (FIP). In addition, the up scope options for the observatory are laid out as well including a fourth instrument: the Heterodyne Receiver for Origins (HERO).

As the optical performance requirements of space telescopes get more stringent, the need to analyze all possible error sources early in the mission design becomes critical. One large telescope with tight performance requirements is the Large Ultraviolet / Optical / Infrared Surveyor (LUVOIR) concept. The LUVOIR concept includes a 15-meter-diameter segmented-aperture telescope with a suite of serviceable instruments operating over a range of wavelengths between 100nm to 2.5um. Using an isolation architecture that involves no mechanical contact between the telescope and the host spacecraft structure allows for tighter performance metrics than current space-based telescopes being flown. Because of this separation, the spacecraft disturbances can be greatly reduced and disturbances on the telescope payload contribute more to the optical performance error. A portion of the optical performance error comes from the disturbances generated from the motion of the Fast Steering Mirror (FSM) on the payload. Characterizing the effects of this disturbance gives insight into the specifications on the FSM needed to achieve the tight optical performance requirements of the overall system. Through analysis of the LUVOIR finite element model and linear optical model given a range of input disturbances at the FSM, the optical performance of the telescope and recommendations for FSM specifications can be determined. The LUVOIR observatory control strategy consists of a multi-loop control architecture including the spacecraft Attitude Control System (ACS), Vibration Isolation and Precision Pointing System (VIPPS), and FSM. This paper focuses on the control loop containing the FSM disturbances and their effects on the telescope optical performance.

First, second, and third-order aberration theory are applied to reduce the degrees of freedom to generate starting designs for freeform imagers. This provides the framework to perform a complete search of the solution space.

CMM metrology provides simple, 3D surface data used for prescription retrieval, figure error, and alignment with high accuracy without null-correctors. Two freeform mirrors for a compact telescope were successfully characterized and aligned using the CMM.

We present a general optical design survey of two-mirror unobstructed plane-symmetric freeform (FF) telescopes to provide a standardized framework and reference for further developments in the field of FF optics. We find that there are fundamentally two main design forms: those that use a positive tilt of the secondary and those that employ a negative rotation to achieve the unobstructed condition. Utilizing this survey, results can be categorized into simple groups of two-mirror unobstructed FF telescopes, analogous to the distinction between a Gregorian-type telescope and Cassegrain-type telescope. Allowing FF surfaces in optical design can enable more compact telescopes while potentially improving the image quality and allowing wider fields of view (FOVs). We define a FF optic as a nonrotationally symmetric mirror or lens, typically with large departures from a best-fit spherical surface (many microns or even millimeters). New manufacturing and testing methods have enabled the production of these types of surfaces. The telescopes we present maintain a 4 ∶ 1 aspect ratio of the FOV and utilize X–Y polynomials for mirror surface description. We impose a plane symmetric constraint on the system and an accessible entrance pupil. We generate charts documenting the relationship between FOV and F / # for the presented optical design forms. We also compare our results to a baseline rotationally symmetric system. These results provide a general method of evaluating baseline designs for two-mirror unobstructed FF telescopes.

Neuroinflammation is a well-characterized pathophysiology occurring in association with the progression of Parkinson’s disease. Characterizing the cellular and molecular basis of neuroinflammation is critical to understanding its impact on the incidence and progression of PD and other neurologic disorders. Inflammasomes are intracellular pro-inflammatory pattern-recognition receptors capable of initiating and propagating inflammation. These cellular complexes are well characterized in the innate immune system and activity of the NLRP3 inflammasome has been reported in microglia. NLRP3 inflammasome activity has been associated with Alzheimer’s disease, and recent reports, from our laboratory and others, indicate that Nlrp3 is required for neuroinflammation and nigral cell loss in animal models of PD. NLRP3 has not yet been characterized in PD patients. Here we characterize NLRP3 in PD using immunohistologic and genetic approaches. Histologic studies revealed elevated NLRP3 expression in mesencephalic neurons of PD patients. Analysis of exome sequencing data for genetic variation of NLRP3 identified multiple single-nucleotide polymorphisms (SNPs) including rs7525979 that was associated with a significantly reduced risk of developing PD. Mechanistic studies conducted in HEK293 cells indicated that the synonymous SNP, NLRP3 rs7525979, alters the efficiency of NLRP3 translation impacting NLRP3 protein stability, ubiquitination state, and solubility. These data provide evidence that dopaminergic neurons are a cell-of-origin for inflammasome activity in PD and are consistent with recent animal studies, suggesting that inflammasome activity may impact the progression of PD., Neuroinflammation: a desirable genetic variant A genetic variant of a protein that mediates neuroinflammatory processes reduces the risk of developing Parkinson’s disease (PD). Previous studies have shown that NLRP3 contributes to the progression of Alzheimer’s disease and PD in animal models. Matthew Havrda at the Geisel School of Medicine at Dartmouth, New Hampshire, USA, and colleagues found high levels of NLRP3 in degenerating dopaminergic neurons in the brains of patients with PD. Interestingly, analyses of genetic sequences coding NLRP3 obtained from the Parkinson’s Progression Markers Initiative revealed an NLRP3 variant associated with a significantly decreased risk of PD. This effect might be due to its reduced activity as the NLRP3 variant formed insoluble aggregates in cells. Further understanding the role of NLRP3 in neurodegenerative diseases could aid the development of novel neuroinflammatory inhibitors.

The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. "Concept-1" is a cold (4 K) 9 m space telescope with five instruments, while "concept 2" consists of a cold 5.9 m telescope and four instruments, providing imaging and spectroscopic capabilities between 5μm and 600μm. The sensitivity provided by the observatory will be a three to four orders of magnitude improvement over currently achieved observational capabilities, allowing to address a wide range of new and so far inaccessible scientific questions, ranging from bio-signatures in the atmospheres of exo-planets to the production of the first metals in the universe right after the end of re-ionization. Here we present the Far Infrared Imager and Polarimeter (FIP) for OST. The camera will cover four bands, 50μm, 100μm, 250μm, and 500μm. In the "concept 1" version of the instrument, FIP will allow for differential polarimetry with the ability to observe two colors simultaneously, while all four bands can be observed simultaneously in total power mode. The confusion limit in the total power mode will be reached in only 8 ms at 500μm, while at 50μm the source density in the sky is so low that at OST's angular resolution of (see manuscript for symbol) 2" in this band the source confusion limit will only be reached after about two hours of integration with the "concept-2" version of FIP ("concept-1" FIP will not be confusion limited at 50m, no matter how long it integrates). Science topics that can be addressed by the camera include, but are not limited to, galactic and extragalactic magnetic field studies, deep galaxy surveys, and outer Solar System objects.

The James Webb Space Telescope is a large, deployable telescope that will operate at cryogenic temperatures at the Earth-Sun Lagrange 2 point. The Webb Optical Telescope Element (OTE) consists of 18 actively controlled Primary Mirror Segment Assemblies (PMSAs), an actively controlled Secondary Mirror Assembly (SMA), and an Aft-Optics Subsystem (AOS) that contains a fixed Tertiary Mirror and a Fine Steering Mirror. The OTE is combined with the Integrated Science Instrument Module (ISIM) to create the full optical train called OTIS (OTE and ISIM). OTIS has recently undergone cryogenic vacuum testing in Chamber A at Johnson Space Center in Houston, TX. A key outcome of this test was to verify there is adequate range of motion in PMSA and SMA actuators to align them to AOS/ISIM under flight-like conditions. The alignment state of the PMSAs and SMA was measured using photogrammetry and cross-checked optically using a variation of a classical Hartmann test. In the “Pass-and-a-Half” (PAAH) configuration, fiber sources near the Cassegrain focus propagate light through the full optical train and small tilts on the PMSAs create an array of spots on the science instrument detectors, mimicking the effect of a Hartmann mask. Comparison of measured and modeled spot arrays provides the alignment state of the SMA and the global tilt of the primary mirror. This paper will discuss the methodology, testing, and analysis performed to measure the alignment state of OTIS using the Hartmann method and verify the primary and secondary mirrors can be successfully aligned on orbit to meet performance requirements.

The Origins Space Telescope (OST) will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did the universe evolve in response to its changing ingredients? How common are life-bearing planets? To accomplish its scientific objectives, OST will operate at mid- and far-infrared wavelengths and offer superlative sensitivity and new spectroscopic capabilities. The OST study team will present a scientifically compelling, executable mission concept to the 2020 Decadal Survey in Astrophysics. To understand the concept solution space, our team studied two alternative mission concepts. We report on the study approach and describe both of these concepts, give the rationale for major design decisions, and briefly describe the mission-enabling technology.

Driven by the development of freeform imaging systems, we have combined several concepts and techniques from the literature to analytically generate unobscured freeform starting point designs that are corrected through the third-order image degrading aberrations. The surfaces used in these starting point designs are described as a base off-axis conic that images stigmatically for the central field point, also known as a Cartesian reflector, with an aspheric departure “cap” (quartic with the aperture) added to the base off-axis conic to correct for the third-order image degrading aberrations. Once the aspheric caps are added to the surfaces, the system is then optimized using higher order freeform terms while leaving second-order terms frozen to preserve the focal length of the system during optimization. This technique is used to survey the three-mirror freeform imager solution space. Several systems that are the result of this technique are shown, with different numbers of internal images, internal pupil conjugates and folding geometries.

Driven by the development of freeform four-mirror solutions, we review and compare analytical methods to generate starting point designs with various states of correction, surface types, symmetry, and obscuration. The advantages and disadvantages of each are examined. We have combined several concepts and techniques from the literature to analytically generate unobscured freeform starting point designs that are corrected through the third-order image degrading aberrations. The surfaces in these starting point designs are described as base off-axis conics that image stigmatically for the central field point, also known as Cartesian reflectors, with an aspheric departure “cap” (quartic with the aperture) added to the Cartesian reflectors. Tilt angles are chosen to cancel field-asymmetric field-linear astigmatism and unobscure the system. Paraxial data from an equivalent on-axis system are used to solve a system of linear equations to determine the magnitude of the aspheric departure “caps” that are placed on top of the base Cartesian reflectors, in order to eliminate the remaining third-order image degrading aberrations. In this approach, each aspheric departure “cap” is centered about the intersection of the optical-axis-ray, also known as the base ray, with the base surface, rather than being centered about the axis of rotational invariance.

When symmetry is broken, the wave-aberration function generalizes to have not only odd-orders but also even-orders. Geometric interpretation of the lowest-order coefficients (i.e., second) and insights offered by consideration of these terms are presented.

As the number of smallsats and cubesats continues to increase [1], so does the interest in the space optics community to miniaturize reflective optical instrumentation for these smaller platforms. Applications of smallsats are typically for the Earth observing community, but recently opportunities for them are being made available for planetary science, heliophysics and astrophysics concepts [2]. With the smaller satellite platforms come reduced instrument sizes that they accommodate, but the specifications such as field of view and working f/# imposed on the smaller optical systems are often the same, or even more challenging. To meet them, and to “fit in the box”, it is necessary to employ additional degrees of freedom to the optical design. An effective strategy to reduce package size is to remove rotational symmetry constraints on the system layout, allowing it to minimize the unused volume by applying rigid body tilts and decenters to mirrors. Requirements for faster systems and wider fields of view can be addressed by allowing optical surfaces to become “freeform” in shape, essentially removing rotational symmetry constraints on the mirrors themselves. This dual approach not only can reduce package size, but also can allow for increased fields of view with improved image quality. Tools were developed in the 1990s to compute low-order coefficients of the imaging properties of asymmetric tilted and decentered systems [3][4]. That approach was then applied to reflective systems with plane symmetry, where the coefficients were used to create closed-form constraints to reduce the number of degrees of freedom of the design space confronting the designer [5][6]. In this paper we describe the geometric interpretation of these coefficients for systems with a plane of symmetry, and discuss some insights that follow for the design of systems without closed-form constraints. We use a common three-mirror design form example to help illustrate these concepts, and incorporate freeform surfaces for each mirror shape. In section II, we evoke the typical form of the wave aberration function taught in most texts on geometrical optics, and then recast it into a general form that no longer assumes rotational symmetry. A freeform surface definition for mirrors is then defined, and the example three-mirror system used throughout this paper is introduced. In section III, the first-order coefficients of the plane symmetric system are discussed, and then the second-order in section IV. In both of these discussions, the example system is perturbed to present the explicit form of the aberration coefficient laid out in section II, and plots are presented using optical design software. Finally, some concluding remarks are given in section V.

NASA’s James Webb Space Telescope (JWST) is a 6.6m diameter, segmented, deployable telescope for cryogenic IR space astronomy. The JWST Observatory architecture includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) element which contains four science instruments (SI), including a guider. The SIs and guider are mounted to a composite metering structure with outer envelope approximate measurements of 2.2x2.2x1.7m. These SI units are integrated to the ISIM structure and optically tested at NASA Goddard Space Flight Center as an instrument suite using an Optical telescope element SIMulator (OSIM). OSIM is a high-fidelity, cryogenic JWST simulator that features a ~1.5m diameter powered mirror. The SIs are aligned to the flight structure’s coordinate system under ambient, clean room conditions using opto-mechanical metrology and customized interfaces. OSIM is aligned to the ISIM mechanical coordinate system at the cryogenic operating temperature via internal mechanisms and feedback from alignment sensors and metrology in six degrees of freedom. SI performance, including focus, pupil shear, pupil roll, boresight, wavefront error, and image quality, is evaluated at the operating temperature using OSIM. This work reports on the as-run ambient assembly and ambient alignment steps for the flight ISIM, including SI interface fixtures and customization and kinematic mount adjustment. The ISIM alignment plan consists of multiple steps to meet the “absolute” alignment requirements of the SIs and OSIM to the flight coordinate system. In this paper, we focus on key aspects of absolute, optical-mechanical alignment. We discuss various metrology and alignment techniques. In addition, we summarize our approach for dealing with and the results of ground-test factors, such as gravity.

This paper describes the critical instrument alignment terms associated with the six-degree of freedom alignment of each the Science Instrument (SI) in the James Webb Space Telescope (JWST), including focus, pupil shear, pupil clocking, and boresight. We present the test methods used during cryogenic-vacuum tests to directly measure the performance of each parameter, the requirements levied on each, and the impact of any violations of these requirements at the instrument and Observatory level.

NASA's James Webb Space Telescope (JWST) is a 6.6m diameter, segmented, deployable telescope for cryogenic IR space astronomy (~40K). The JWST Observatory includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) that contains four science instruments (SI) and the fine guider. The SIs are mounted to a composite metering structure. The SI and guider units were integrated to the ISIM structure and optically tested at the NASA Goddard Space Flight Center as a suite using the Optical Telescope Element SIMulator (OSIM). OSIM is a full field, cryogenic JWST telescope simulator. SI performance, including alignment and wave front error, were evaluated using OSIM. We describe test and analysis methods for optical performance verification of the ISIM Element, with an emphasis on the processes used to plan and execute the test. The complexity of ISIM and OSIM drove us to develop a software tool for test planning that allows for configuration control of observations, associated scripts, and management of hardware and software limits and constraints, as well as tools for rapid data evaluation, and flexible re-planning in response to the unexpected. As examples of our test and analysis approach, we discuss how factors such as the ground test thermal environment are compensated in alignment. We describe how these innovative methods for test planning and execution and post-test analysis were instrumental in the verification program for the ISIM element, with enough information to allow the reader to consider these innovations and lessons learned in this successful effort in their future testing for other programs.

The James Webb Space Telescope includes the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI) including a Guider. We performed extensive structural, thermal, and optical performance(STOP) modeling in support of all phases of ISIM development. In this paper, we focus on modeling and results associated with test and verification. ISIMs test program is bound by ground environments, mostly notably the 1g and test chamber thermal environments. This paper describes STOP modeling used to predict ISIM system performance in 0g and at various on-orbit temperature environments. The predictions are used to project results obtained during testing to on-orbit performance.

Large astronomical missions are usually general-purpose telescopes with a suite of instruments optimized for different wavelength regions, spectral resolutions, etc. Their end-to-end (E2E) simulations are typically photons-in to flux-out calculations made to verify that each instrument meets its performance specifications. In contrast, smaller space missions are usually single-purpose telescopes, and their E2E simulations start with the scientific question to be answered and end with an assessment of the effectiveness of the mission in answering the scientific question. Thus, E2E simulations for small missions consist a longer string of calculations than for large missions, as they include not only the telescope and instrumentation, but also the spacecraft, orbit, and external factors such as coordination with other telescopes. Here, we illustrate the strategy and organization of small-mission E2E simulations using the Galaxy Evolution Spectroscopic Explorer (GESE) as a case study. GESE is an Explorer/Probe-class space mission concept with the primary aim of understanding galaxy evolution. Operation of a small survey telescope in space like GESE is usually simpler than operations of large telescopes driven by the varied scientific programs of the observers or by transient events. Nevertheless, both types of telescopes share two common challenges: maximizing the integration time on target, while minimizing operation costs including communication costs and staffing on the ground. We show in the case of GESE how these challenges can be met through a custom orbit and a system design emphasizing simplification and leveraging information from ground-based telescopes.

A wide array of general astrophysics studies including detecting and characterizing habitable exoplanets could be enabled by a future large segmented telescope with sensitivity in the UV, optical, and infrared bands. When paired with a starshade or coronagraph, such an observatory could enable direct imaging and detailed spectroscopic observations of nearby Earth-like habitable zone planets. Over the past several years, a laboratory-based Visible Nulling Coronagraph (VNC) has evolved to reach requisite contrasts over a ~ 1 nm bandwidth at narrow source angle separation using a segmented deformable mirror in one arm of a Mach-Zehnder layout. More recent efforts targeted broadband performance following the addition of two sets of half-wave Fresnel rhomb achromatic phase shifters (APS) with the goal of reaching 10-9 contrast, at a separation of 2λ/D, using a 40 nm (6%) bandwidth single mode fiber source. Here we present updates on the VNC broadband nulling effort, including approaches to addressing system contrast limitations.

The James Webb Space Telescope's (JWST) end-to-end optical system will be tested in a cryogenic vacuum environment before launch at NASA Johnson Space Center’s (JSC) Apollo-era, historic Chamber A thermal vacuum facility. During recent pre-test runs with a prototype “Pathfinder” telescope, the vibration in this environment was found to be challenging for the baseline test approach, which uses phase retrieval of images created by three sub-apertures of the telescope. To address the vibration, an alternate strategy implemented using classic Hartmann test principles combined with precise mirror mechanisms to provide a testing approach that is insensitive to the dynamics environment of the chamber. The measurements and sensitivities of the Hartmann approach are similar to those using phase retrieval over the original sparse aperture test. The Hartmann test concepts have been implemented on the JWST Test Bed Telescope, which provided the rationale and empirical evidence indicating that this Hartmann style approach would be valuable in supplementing the baseline test approach. This paper presents a Hartmann approach implemented during the recent Pathfinder test along with the test approach that is currently being considered for the full optical system test of JWST. Comparisons are made between the baseline phase retrieval approach and the Hartmann approach in addition to demonstrating how the two test methodologies support each other to reduce risk during the JWST full optical system test.

Measuring the B-mode polarization of the CMB radiation requires a detailed understanding of the projection of the detector onto the sky. We show how the combination of scan strategy and processing generates a cylindrical beam for the spectrum measurement. Both the instrumental design and the scan strategy reduce the cross coupling between the temperature variations and the B-modes. As with other polarization measurements some post processing may be required to eliminate residual errors.

The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8–200 µm, in five spectral pass bands, for outer planet fly-by missions is described. The dual-telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field-of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

Glioblastomas (GBMs) are the most aggressive type of primary brain tumor in adults, the second leading cause of cancer-related death in children, and are incurable using currently available treatment modalities. GBMs are characterized by the presence of primitive glioma stem-like cell subpopulations that resist chemotherapy and sustain disease progression. In this study, we found that Benztropine, a muscarinic acetylcholine receptor (mAChR) inhibitor, suppresses glioma cell proliferation and sensitizes these cells to treatment with Temozolomide. Modeling the development of Temozolomide resistance in vitro, we identified a subpopulation of glioma cells, defined by the co-expression of CD44, CD15, and PDGFRa that was resistant to Temozolomide. This chemo-resistant subpopulation was phenotypically similar to oligodendroglial progenitor cells (OPC-like); a stem-like cell population important in the initiation and progression of glioblastoma known to be modulated by mAChR signaling. The addition of the mAChR inhibitor, benztropine, dramatically reduced the emergence of this Temozolomide-resistant sub-population. To begin understanding the mechanism of action of benztropine on GBM cells, we analyzed the effect of this drug on a panel of mitotic drivers that have been implicated in glioma initiation and progression. Sub-lethal doses of Benztropine alone or in combination with temozolomide repressed the PDGF-signaling axis as characterized by a significant reduction of PDGFA secretion and PDGFRA activation. We also developed an in vivo model of Temozolomide resistance to determine whether Benztropine could improve the survival of animals harboring glioma xenografts that had recurred following treatment with Temozolomide. These in vivo studies demonstrated that Benztropine alone improves animal survival as compared with vehicle controls and that Benztropine combined with Temozolomide reduces glioma growth following initial Temozolomide treatment and improves survival in mice xenografted with human GBM cells. Taken together, our results suggest that Benztropine might be targeting glioma stem cells by altering the glioma stem cell microenvironment. These findings support a potential role for the use of adjuvant Benztropine for the clinical management of GBM. Citation Format: Damian A. Almiron Bonnin, Myung Chang Lee, Joseph M. Howard, Alison L. Young, Matthew C. Havrda. Benztropine enhances temozolomide sensitivity by restricting the growth of drug-resistant glioma stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1958.

The past, present, and future usage of Freeform Optics at NASA are discussed in this presentation. Article not available.

Virtually all malignant gliomas become drug-resistant and recur after initial treatment, recurrent tumors are fatal within two-years, and no therapies exist that cure gliomas. The recognition that subpopulations of primitive cells with an oligodendrocyte precursor-like (OPC-like) phenotype capable of resisting standard therapy and contributing to recurrence, frames the question of whether adjuvant therapies designed to modify or eliminate OPC-like cells could slow the progression of glioma. Agents that force the differentiation of treatment-resistant OPC-like glioma cells, a phenomenon that requires cessation of proliferation, are compelling candidates for targeting OPC-like GSCs. Recently, it was observed that OPC proliferation was driven by activation of the M1, M3 and M4 muscarinic receptors. In another report, a large-scale drug screen designed to seek drugs to induce OPC differentiation in the context of multiple sclerosis identified a muscarinic receptor antagonist, benztropine (a.k.a. Cogentin), as a promoter of OPC differentiation and cell cycle exit. We have conducted studies in glioma cell lines supporting a role for benztropine in suppressing the development of drug-resistance to the standard glioma chemo-therapeutic temozolomide (TMZ). Upon treatment with TMZ, we identified the emergence of an OPC-like subpopulation of glioma cells identifiable by the co-expression of CD44, CD15 and PDGFRa. Treatment with pre-inhibitory doses of benztropine significantly reduced the TMZ IC50 in all glioma lines examined in association with blocking emergence of the CD44/CD15/PDGFR-positive subpopulation. Ongoing studies are designed to determine the tumor initiating potential of the CD44/CD15/PDGFR-positive subpopulation and whether benztropine will suppress the development of TMZ resistance in animal models of glioma. Citation Format: Damian A. Almiron Bonnin, Joseph M. Howard, Alison L. Young, Mark A. Israel, Matthew C. Havrda. The muscarinic receptor antagonist, benztropine, blocks the expansion of a temozolomide resistant subpopulation of glioma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2047. doi:10.1158/1538-7445.AM2017-2047

Linear Optical Models are wavefront based sensitivity models that are used for Monte-Carlo studies for boresight and structural-thermal-optical analyses, as well as wavefront sensing simulations. Applications to NASA’s WFIRST mission are described.

A suite of CODE V macros has been developed to assist the optical designer in visualizing and manipulating optical data. Limits within the CODE V macro language and graphics functions are surpassed by accessing a MATLAB subroutine. A number of extension macros are discussed and examples are shown.

The image quality improvement for three-mirror systems by Freeform Optics is surveyed over various f-number and field specifications. Starting with the Korsch solution, we increase the surface shape degrees of freedom and record the improvements.

This paper summarizes the optical integrated modeling efforts for the James Webb Space Telescope reported from 2003 to 2009. The topics include: 1) development of the linear optical model (or LOM), 2) the extension of the LOM to a field of view, 3) tolerance analysis of figure and alignment modes of the telescope, 4) introduction of math software toolkits, 5) system level modeling and closed loop alignment updates of the observatory on orbit, and 6) primary mirror figure compensation of large figure aberration.

The ATALST (Advanced Technology for Large Aperture Space Telescopes) effort has presented several design incarnations. Here we will compare the 9.2m segmented, the 8m monolithic on-axis and 8m x 6m off-axis concepts.

The James Web Space Telescope (JWST) is a large, infrared-optimized space telescope scheduled for launch in 2014. System-level verification of critical performance requirements will rely on integrated observatory models that predict the wavefront error accurately enough to verify that allocated top-level wavefront error of 150 nm root-mean-squared (rms) through to the wave-front sensor focal plane is met. The assembled models themselves are complex and require the insight of technical experts to assess their ability to meet their objectives. This paper describes the systems engineering and modeling approach used on the JWST through the detailed design phase.