This PDF file contains the front matter associated with SPIE Proceedings Volume 7010, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Herschel is the next astronomy mission in the European Space Agency (ESA) science programme. It is currently in the final stages of assembly and verification in ESA's ESTEC facility in Noordwijk, and is scheduled to be flown to the launch site at Europe's Spaceport in Kourou later this year. Herschel will carry a 3.5 metre diameter passively cooled Cassegrain telescope which is the largest of its kind and utilises novel silicon carbide technology. The science payload comprises three instruments: two direct detection cameras/medium resolution spectrometers, PACS and SPIRE, and a very high resolution heterodyne spectrometer, HIFI. The focal plane units are housed inside a superfluid helium cryostat based on ISO legacy. Herschel will be launched by an Ariane 5 ECA together with the Planck satellite into a transfer trajectory towards the operational orbit around L2. When operational Herschel will provide unprecedented observational opportunities in the 55-672 μm spectral range, much of which has never before been accessible from a space observatory. It is an observatory facility available to the worldwide astronomical community, nominally almost 20,000 hours will be available for astronomy, 32% is guaranteed time and the remainder is open to the general astronomical community through a standard competitive proposal procedure. The initial Key Programme Announcement of Opportunity (AO) was issued in Feb 2007. Both the guaranteed and open time Key Programmes have been selected and are introduced, and future observing opportunities are outlined.

This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI), to be launched onboard of ESA's Herschel Space Observatory, by 2008. It includes the first results from the instrument level tests. The instrument is designed to be electronically tuneable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 km/s with a high sensitivity. This will enable detailed investigations of a wide variety of astronomical sources, ranging from solar system objects, star formation regions to nuclei of galaxies. The instrument comprises 5 frequency bands covering 480-1150 GHz with SIS mixers and a sixth dual frequency band, for the 1410-1910 GHz range, with Hot Electron Bolometer Mixers (HEB). The Local Oscillator (LO) subsystem consists of a dedicated Ka-band synthesizer followed by 7 times 2 chains of frequency multipliers, 2 chains for each frequency band. A pair of Auto-Correlators and a pair of Acousto-Optic spectrometers process the two IF signals from the dual-polarization front-ends to provide instantaneous frequency coverage of 4 GHz, with a set of resolutions (140 kHz to 1 MHz), better than < 0.1 km/s. After a successful qualification program, the flight instrument was delivered and entered the testing phase at satellite level. We will also report on the pre-flight test and calibration results together with the expected in-flight performance.

The Photodetector Array Camera and Spectrometer (PACS) is one of the three science instruments for ESA's far infrared and submillimeter observatory Herschel. It employs two Ge:Ga photoconductor arrays (stressed and unstressed) with 16 × 25 pixels, each, and two filled silicon bolometer arrays with 16 × 32 and 32 × 64 pixels, respectively, to perform imaging line spectroscopy and imaging photometry in the 60 - 210μm wavelength band. In photometry mode, it will simultaneously image two bands, 60 - 85μm or 85 - 125μm and 125 - 210μm, over a field of view of ~ 1.75' × 3.5', with close to Nyquist beam sampling in each band. In spectroscopy mode, it will image a field of ~ 50" × 50", resolved into 5 × 5 pixels, with an instantaneous spectral coverage of ~ 1500 km/s and a spectral resolution of ~ 175 km/s. In both modes the performance is expected to be not far from background-noise limited, with sensitivities (5σ in 1h) of ~ 4 mJy or 3 - 20 × 10^-18W/m², respectively. We summarize the design of the instrument, describe the observing modes in combination with the telescope pointing modes, report results from instrument level performance tests and calibration of the Flight Model, and present our current prediction of the in-orbit performance of the instrument based on the ground tests.

SPIRE, the Spectral and Photometric Imaging Receiver, is a submillimetre camera and spectrometer for Herschel. It comprises a three-band camera operating at 250, 350 and 500 µm, and an imaging Fourier Transform Spectrometer covering 194-672 μm. The photometer field of view is 4x8 arcmin., viewed simultaneously in the three bands. The FTS has an approximately circular field of view of 2.6 arcmin. diameter and spectral resolution adjustable between 0.04 and 2 cm^-1 ( λ/▵λ=20-1000 at 250 μm). Following successful testing in a dedicated facility designed to simulate the in-flight operational conditions, SPIRE has been integrated in the Herschel spacecraft and is now undergoing system-level testing prior to launch. The main design features of SPIRE are reviewed, the key results of instrument testing are outlined, and a summary of the predicted in-flight performance is given.

Herschel is an ESA spaceborne far infrared observatory, to be launched late 2008. It's key science objectives emphasize specifically the formation of stars and Galaxies. The focal plane of the 3.5m diameter telescope is shared by three instruments located in the cryostat: PACS (imaging photometer and integral field line spectrometer, operating from 35μm to 205μm wavelength); SPIRE (imaging photometer and Mach-Zender interferometer, operating from 194μm to 572μm wavelength); and HIFI (heterodyne detector, from 157 to 625μm wavelength). Infrared straylight rejection is one of the key performances of the Herschel observatory. In this paper, we present the straylight requirements, some specific design issues, the estimated performances and test results.

The Spectral and Photometric Imaging Receiver (SPIRE) is one of three scientific instruments onboard the European Space Agency (ESA)'s Herschel Space Observatory. The low to medium resolution spectroscopic capability of SPIRE is provided by an imaging Fourier transformspectrometer of the Mach-Zehnder configuration. Instrument performance of the SPIRE flight model was evaluated during a series of test campaigns. The SPIRE instrument performance verification was completed with instrument delivery to ESA in early 2007. In this paper we present the resulting performance characteristics of the SPIRE spectrometer flight model as determined from these test campaigns. We verify the instrument's conformance with fundamental design specifications such as spectral coverage and resolution. Variations across the imaging array of such properties as spectral resolution, vignetting, and instrumental line shape are explored. Additionally, instrumental artefacts observed during final verification testing are identified and quantified; with explanations provided for potential causes, and proposed methods to minimize their impact on scientific observations described.

The Photodetector Array Camera and Spectrometer (Pacs) instrument aboard the Herschel space observatory contains an integral field spectrometer with two camera channels which consist of 25 linear arrays of 16 stressed Gallium doped Germanium crystals (Ge:Ga) each. The space radiation environment induces changes in the detector performance. Therefore, testing the Ge:Ga detectors under space radiation environment during the commissioning phase (CP) is important for optimization of later detector operation in orbit. The test program for Ge:Ga detector tuning during this phase has been designed according to findings obtained in laboratory experiments: Protons as well as a ¹³⁷Cs-γ-source have been used to simulate the space radiation environment and to induce the radiation impacts on the photoconductor arrays. From comparison of the performance of the detectors during CP versus laboratory tests the best strategy for operating the detectors during scientific observations will be derived. This includes annealing, proposals for on-board data reduction algorithms and the best estimated strategy for well-calibrated scientific measurements.

The AKARI, Japanese infrared astronomical satellite, is a 68.5 cm cooled telescope with two focal-plane instruments providing continuous sky scan at six wavelength bands in mid- and far-infrared. The instruments also have capabilities of imaging and spectroscopy in the wavelength range 2-180 μm in the pointing observations occasionally inserted into the continuous survey. AKARI was launched on 21st Feb. 2006, and has performed the all-sky survey as well as 5380 pointing observations until the liquid helium exhaustion on 26th Aug. 2007. The all sky survey covers more than 90 percent of the entire sky with higher spatial resolutions and sensitivities than the IRAS. First version of the infrared source catalogue will be released in 2009. Here we report the overview of the mission, highlights on the scientific results as well as the performance of the focal-plane instruments. We also present the observation plan with the near infrared camera during the post-helium mission phase started in June 2008.

AKARI is the first Japanese astronomical infrared satellite mission orbiting around the Earth in a sun-synchronous polar orbit at the altitude of 700 km. One of the major observation programs of the AKARI is an all-sky survey in the mid- to far-infrared spectral regions with 6 photometric bands. The mid-infrared part of the AKARI All-Sky Survey was carried out with the Infrared Camera (IRC) at the 9 and 18 µm bands with the sensitivity of about 50 and 120 mJy (5σ per scan), respectively. The spatial resolution is about 9.4" at both bands. AKARI mid-infrared (MIR) all-sky survey substantially improves the MIR dataset of the IRAS survey of two decades ago and provides a significant database for studies of various fields of astronomy ranging from star-formation and debris disk systems to cosmology. This paper describes the current status of the data reduction and the characteristics of the AKARI MIR all-sky survey data.

The Infrared Camera (IRC) is one of two focal-plane instruments on the AKARI satellite. It is designed for wide-field deep imaging and low-resolution spectroscopy in the near- to mid-infrared (1.8-26.5 micron) in the pointed observation mode of AKARI. The IRC is also operated in the survey mode to make an All-Sky Survey at 9 and 18 microns. The IRC is composed of three channels. The NIR channel (1.8-5.5 micron) employs a 512x412 InSb photodiode array, whereas both the MIR-S (4.6-13.4 micron) and MIR-L (12.6-26.5 micron) channels use 256x256 Si:As impurity band conduction (IBC) arrays. Each of the three channels has a field-ofview of approximately 10x10 arcmin., and they are operated simultaneously. The NIR and MIR-S channels share the same field-of-view by virtue of a beam splitter. The MIR-L observes the sky about 25 arcmin. away from the NIR/MIR-S field-of-view. The in-flight performance of the IRC has been confirmed to be in agreement with the pre-flight expectation. More than 4000 pointed observations dedicated for the IRC are successfully completed, and more than 90% of the sky are covered by the all-sky survey before the exhaustion of the Akari's cryogen. The focal-plane instruments are currently cooled by the mechanical cooler and only the NIR channel is still working properly. Brief introduction, in-flight performance and scientific highlights from the IRC cool mission, together with the result of performance test in the warm mission, are presented.

We present the in-orbit performance of slow-scan observation of the Far-Infrared Surveyor (FIS) onboard the AKARI satellite. The FIS, one of the two focal-plane instruments of AKARI, has four photometric bands from 50-180 μm with two kinds of Ge:Ga array detectors. In addition to the All-Sky Survey, the FIS also took images of specific targets by the slow-scan. Because of the longer exposure time on a targeted source, the sensitivity in the slow-scan mode is 1-2 orders of magnitude better than that in the All-Sky Survey mode. In order to evaluate the point spread functions (PSFs), several bright point-like objects such as asteroids, stars, and galaxies were observed. Though significant enhancements are seen at the tails of the PSFs, the derived full width at the half maximum (FWHM) are consistent with those expected from the optical simulation and the laboratory measurements; ~40" for two shorter wavelength bands and ~60" for two longer wavelength bands, respectively. The absolute photometric calibration has been performed by observing well established photometric calibration standards (asteroids and stars) in a wide range of fluxes. After the establishment for the method of the aperture photometry, the photometric accuracy for point sources is less than 10% in all bands.

We report the in-orbit performance of the AKARI/Far-Infrared Surveyor Ge:Ga photoconductors, focusing on the transient response and the radiation effects, to perform the characterization of these effects for data analyses. The behavior for these effects is found to be significantly different between the Short-Wavelength and Long-Wavelength array detectors of the FIS, most probably due to the difference in the array configuration. We discuss cosmic-ray radiation effects, referring to the results of pre-flight proton-beam irradiation measurements. We also describe our efforts to correct the slow transient response of the detectors by adopting a physical approach.

We have developed an imaging Fourier transform spectrometer (iFTS) for space-based far-infrared astronomical observations. The iFTS employs newly developed photoconductive detector arrays with a capacitive transimpedance amplifier, which makes the iFTS a completely unique instrument. The iFTS was installed as a function of the far-infrared instrument (FIS: Far-Infrared Surveyor) on the Japanese astronomical satellite, AKARI, which was launched on February 21, 2006 (UT) from the Uchinoura Space Center. The iFTS had worked properly in the space environment as well as in laboratory for more than one year before liquid helium ran out on August 26, 2007. The iFTS was operated nearly six hundreds of pointed observations. More than one hundred hours of astronomical observations and almost the same amount of time for calibrations have been carried out in the mission life. Meanwhile, it becomes clear that the detector transient effect is a considerable factor for FTSs with photoconductive detectors. In this paper, the instrumentation of the iFTS and interesting phenomena related to FTSs using photoconductive detectors are described, and the calibration strategy of the iFTS is discussed briefly.

The Wide Field Infrared Survey Explorer is a NASA Medium Class Explorer mission to perform a high-sensitivity, high resolution, all-sky survey in four infrared wavelength bands. The science payload is a 40 cm aperture cryogenically cooled infrared telescope with four 10242 infrared focal plane arrays covering from 2.8 to 26 μm. Mercury cadmium telluride (MCT) detectors are used for the 3.3 μm and 4.6 μm channels, and Si:As detectors are used for the 12 μm and 23 μm wavelength channels. A cryogenic scan mirror freezes the field of view on the sky over the 9.9-second frame integration time. A two-stage solid hydrogen cryostat provides cooling to temperatures less than 17 K and 8.3 K at the telescope and Si:As focal planes, respectively. The science payload collects continuous data on orbit for the seven-month baseline mission with a goal to support a year-long mission, if possible. As of the writing of this paper, the payload subassemblies are complete, and the payload has begun integration and test. This paper provides a payload overview and discusses instrument status and performance.

SPICA (Space Infrared Telescope for Cosmology and Astrophysics) is an astronomical mission optimized for mid- and far-infrared astronomy with a cryogenically cooled 3.5 m telescope. Its high spatial resolution and unprecedented sensitivity in the mid- and far-infrared will enable us to address a number of key problems in present-day astronomy, ranging from the star-formation history of the universe to the formation of planets. To reduce the mass of the whole mission, SPICA will be launched at ambient temperature and cooled down on orbit by mechanical coolers on board with an efficient radiative cooling system, a combination of which allows us to have a 3.5-m class cooled (5 K) telescope in space with moderate total weight (3t). SPICA is proposed as a Japanese-led mission together with extensive international collaboration. The assessment study on the European contribution to the SPICA project has started under the framework of the ESA Cosmic Vision 2015-2025. US and Korean participations are also being discussed extensively. The target launch year of SPICA is 2017.

The Japanese led Space Infrared telescope for Cosmology and Astrophysics (SPICA) will observe the universe over the 5 to 210 micron band with unprecedented sensitivity owing to its cold (~5 K) 3.5m telescope. The scientific case for a European involvement in the SPICA mission has been accepted by the ESA advisory structure and a European contribution to SPICA is undergoing an assessment study as a Mission of Opportunity within the ESA Cosmic Vision 1015-2015 science mission programme. In this paper we describe the elements that are being studied for provision by Europe for the SPICA mission. These entail ESA directly providing the cryogenic telescope and ground segment support and a consortium of European insitutes providing a Far Infrared focal plane instrument. In this paper we describe the status of the ESA study and the design status of the FIR focal plane instrument.

The SPICA, Japanese next generation infrared space telescope with a cooled 3.5 m primary mirror, will be a quite unique observatory in the mid and far-infrared with unprecedented sensitivity and the spatial resolving power. Here we briefly describe the key scientific objectives which can be performed only with SPICA, based on its unique design concepts. We then describe the scientific requirements for the focal plane instruments, and summarize the constraints on the various resources available for the focal plane instruments, derived from the spacecraft system design. We also outline the concept of the planned focal plane instruments, and the future development plan. Within the focal-plane instrument space (2.5m diameter, 0.5m height), two major instruments are so far planned to be equipped: one is a mid-infrared instrument, consisting of a mid-infrared camera, mid-infrared spectrometers, and a midinfrared coronagraph, while the another is a far-infrared camera and spectrometer. The mid-infrared camera will consist of four channels covering 5-38 μm with approximately 25-40 square arcminutes, while the mid-infrared spectrometer will have high-dispersion (R=30000) channels at 4-18 μm and moderate-dispersion (R=3000) channels at 16-38 μm. The mid-infrared coronagraph will have both imaging and spectroscopic capability at 5-27 μm, with the contrast higher than 10^-6. As for the far-infrared camera and spectrometer, a Fourier-type imaging spectrometer covering 30-210 μm is proposed and extensively studied by the European consortium (SAFARI consortium). A far-infrared and sub-millimeter grating spectrometer instrument is also under consideration by the US SPICA team.

The scientific capabilities of the James Webb Space Telescope fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dustenshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems.

The James Webb Space Telescope (JWST) is a 6.5-meter, space telescope designed for infrared imaging and spectroscopy. Its planned launch in 2013, aboard an Ariane 5, will place it in n L2 orbit. The JWST program is a cooperative program with the Goddard Space Flight Center (GSFC) managing the project for NASA. The prime contractor for JWST is Northrop Grumman Space Technology (NGST). JWST's international partners are the European Space Agency (ESA) and the Canadian Space Agency (CSA). JWST will address four major science themes: First light and re-ionization; the assembly of galaxies, the birth of stars and protoplanetary systems; and the formation of planetary systems and the origins of life. We discuss the design of the observatory as it is currently base-lined, and review recent progress with the observatory.

The James Webb Space Telescope (JWST) is NASA's next great astronomical mission. At the time of this paper, the mission has just passed its preliminary design review. This paper will visit three areas of significant maturation since the design was initially introduced. The three areas discussed are; addition of a heater to the fine steering mirror, spacecraft bus rearchiteture, and redesign of the sunshield core. Each of these design evolutions enables the mission through improved performance, reduced risk or complexity. These three design changes are examples of the efforts being exerted on the other aspects of the design that are not covered in this paper.

The James Webb Space Telescope (JWST) is a 6.5 meter cryogenic observatory planned to launch in 2013. The observatory includes a three mirror anastigmat telescope with a deployed 18 segment primary mirror. Unlike the Hubble Space Telescope (HST), JWST will be difficult to service and therefore the development team needs to be highly confident the telescope will work after launch. Consequently, it is imperative that the team building JWST apply the lessons learned from the HST program so as to avoid repeating mistakes that led to a major optical error in HST. The purpose of this paper is to summarize what the JWST program is doing to apply the lessons learned from HST. It includes a summary of how the HST optical error was made, the lessons learned there from, and how the JWST program is applying these lessons to avoid the mistakes of the past and ensure correct JWST optical performance.

With its high Strehl ratio near- and mid-infrared imaging capabilities, wide field of view, and multiple spectroscopic options, the James Webb Space Telescope (JWST) will provide crucial information on the circumstellar environments of stars thought to harbor debris disks, brown dwarfs or extrasolar giant planets. However, the successful study of such faint targets around nearby, bright stars requires the effective removal of the target star's contribution from the image. In this work, we use simple models of the temporal behavior JWST's wavefront error of JWST over time to examine whether frequent measurements of that changing wavefront can be used to provide an effective point spread function subtraction for high-contrast imaging studies without use of coronagraphic techniques.

The James Webb Space Telescope (JWST) is a large aperture (6.6 m primary mirror) cryogenic telescope with active control of the segmented primary and secondary mirror optical elements. The architecture of the telescope makes full end-to-end testing on the ground prohibitive due to both cost and technical considerations. Additionally, because the telescope will be launched in a folded configuration to fit in the Ariane V launch fairing and aligned during flight using image-based Wavefront Sensing and Control (WFS&C), the telescope cannot be tested in the classical "test-as-you-fly" architecture. Due to these considerations, the primary optical performance requirements will be verified through analysis. In order to have high confidence in this approach, a robust analysis validation program has been developed based on testing from the component level through the integrated telescope level. This verification approach focuses on ground testing at the telescope level to ensure there will be adequate range in the adjustable optics for alignment on orbit. In addition to the incremental test program planned for optical verification, a double-pass sampled aperture test of the integrated telescope and instruments is planned at flight-like temperatures as a crosscheck to the analytic verification for flight. Error budgets have been developed to understand the uncertainty propagation through the test and analysis program.

It is imperative that we have high confidence that the optical performance capability of JWST is well-understood before launch. With the telescope operating at cryogenic temperatures and sporting a 6.6 meter primary mirror diameter, the optical metrology equipment required to measure the optical performance can be quite complex. The JWST Test team undertook an effort to greatly simplify the optical metrology approach, while retaining the key measurements and verification methodology. The result is a cryogenic optical test configuration and implementation using Chamber A at NASA's Johnson Space Center that uses the science instruments to help understand JWST's optical performance.

Instantaneous phase shifting interferometry is key to successful development and testing of the large, deployable, cryogenic telescope for the James Webb Space Telescope (JWST) mission. Two new interferometers have been developed to meet the needs of the JWST program. Spatially Phase-Shifted Digital Speckle Pattern Interferometer (SPSDSPI) was developed to verify structural deformations to nanometer level accuracy in large, deployable, lightweight, precision structures such as the JWST telescope primary mirror backplane. Multi- wavelength interferometer was developed to verify the performance of the segmented primary mirror at cryogenic temperatures. This paper discusses application of SPS-DSPI for measuring structural deformations in large composite structures at cryogenic temperatures. Additionally development of a multi-wavelength interferometer for verifying JWST OTE primary mirror performance at cryogenic temperatures will be discussed.

From its orbit around the Earth-Sun second Lagrange point some million miles from Earth, the James Webb Space Telescope (JWST) will be uniquely suited to study early galaxy and star formation with its suite of infrared instruments.^[1] To maintain exceptional image quality using its 6.6 meter segmented primary mirror, wavefront sensing and control (WFS&C) is vital to ensure the optical alignment of the telescope throughout the mission. After deployment of the observatory structure and mirrors from the "folded" launch configuration, WFS&C is used to align the telescope^[2], as well as maintain that alignment. WFS&C verification includes the verification of the software and its incorporated algorithms, along with the supporting aspects of the integrated ground segment, instrumentation, and telescope through increasing levels of assembly. The software and process are verified with the Integrated Telescope Model (ITM), which is a Matlab/Simulink integrated observatory model which interfaces to CodeV/OSLO/IDL. In addition to lower level testing, the Near-Infrared Camera^[3] (NIRCam) with its wavefront sensing optical components is verified with the other instruments with a cryogenic optical telescope simulator (OSIM) before moving on to the final WFS&C testing in Chamber A at the Johnson Space Center (JSC) where additional observatory verification occurs.

MIRI is the mid-IR instrument for the James Webb Space Telescope and provides imaging, coronography and integral field spectroscopy over the 5-28μm wavelength range. MIRI is the only instrument which is cooled to 7K by a dedicated cooler, much lower than the passively cooled 40K of the rest of JWST, which introduces unique challenges. The paper will describe the key features of the overall instrument design. The flight model design of the MIRI Optical System is completed, with hardware now in manufacture across Europe and the USA, while the MIRI Cooler System is at PDR level development. A brief description of how the different development stages of the optical and cooling systems are accommodated is provided, but the paper largely describes progress with the MIRI Optical System. We report the current status of the development and provide an overview of the results from the qualification and test programme.

The present paper describes the different steps leading to the Flight Model integration of the Mid-Infra Red IMager Optical Bench MIRIM-OB which is part of the scientific payload of the JWST. In order to demonstrate a space instrument capability to survive the challenging space environment and deliver the expected scientific data, a specific development approach is applied in order to reduce the high level of risks. The global approach for MIRIM-OB, and the principal results associated to the two main models, the Structural Qualification Model for vibration and the Engineering and Test Model for optical performance measured in the infra red at cryogenic temperature will be described in this paper.

One of the main objectives of the instrument MIRI, the Mid-InfraRed Instrument, of the JWST is the direct detection and characterization of extrasolar giant planets. For that purpose, a coronagraphic device including three Four-Quadrant Phase Masks and a Lyot coronagraph working in mid-infrared, has been developed. We present here the results of the first test campaign of the coronagraphic system in the mid-infrared in the facility developed at the CEA. The performances are compared to the expected ones from the coronagraphic simulations. The accuracy of the centering procedures is also evaluated to validate the choice of the on-board centering algorithm.

The Fine Guidance Sensor (FGS) of the James Webb Space Telescope (JWST) features a tunable filter imager (TFI) module covering the wavelength range from 1.6 to 4.9 μm at a resolving power of ~100 over a field of view of 2.2'x2.2'. TFI also features a set of 4 occulting spots for coronagraphy. A review of the current design and development status of TFI is presented along with two key TFI science programs: the detection of first light, high-redshift Lyα emitters and the detection/characterization of exoplanets.

The Near Infrared Camera (NIRCam) for the James Webb Space Telescope (JWST) has undergone Pathfinder component testing and evaluation. This paper presents the opto-mechanical test results. An overview of the optomechanical system requirements is provided, followed by a discussion of the opto-mechanical system design and assembly process. Tolerances in the opto-mechanical system as they relate to system level alignment are also presented. Mechanical analysis related to vibration and thermal behavior of the design is shown. Finally, the overall performance of the opto-mechanical system is discussed as it relates to instrument optical performance.

The Near InfraRed Camera (NIRCam) for the James Webb Space Telescope (JWST) is a refracting instrument. Its unique optical performance derives from the Lithium Fluoride, Barium Fluoride and Zinc Selenide lenses that provide aberration and color correction over the large operating wavelengths, 0.6-5 microns. This paper describes cryogenic test results of the mounted camera lenses in a flight-like configuration. These data, which evaluate the foundation for NIRCam optical performance, reveals design strengths and challenges. This is a follow-up paper from SPIE paper 590409 (1) which presented the initial camera lens design.

The James Webb Space Telescope (JWST) mission is a collaborative project between the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA) and the Canadian Space Agency (CSA). On board JWST, the NIRSpec instrument developed by EADS Astrium for ESA is a near-infrared spectrograph covering the 0.6-5.0 μm domain at spectral resolutions of 100, 1000 and 2700. NIRSpec will be primarily operated as a multi-object spectrograph (MOS) but it also includes an integral field unit (IFU) allowing to continuously sample a 3"x3" field of view with 0.1". This IFU, based on the "advanced" image slicer concept, is a very compact athermal unit made of aluminium. The slicer, pupil and slit mirror arrays are each machined from monolithic blocks using diamond-turning techniques. This paper presents the integral-field spectroscopy (IFS) mode of NIRSpec. After a brief presentation of its main scientific objectives and expected performance, we will focus on its implementation in NIRSpec and the design of the IFU to the diamond machining techniques applied for manufacturing. We will finish with a presentation of the status of the development and of recent results from mirror machining and metrology.

Although there is some success in finding Near Earth asteroids from ground-based telescopes, there is a marked advantage in performing the search from space. The ability to search at closer elongations from the sun and being able to observe continuously, allowing quick revisits of new asteroids, are some of the unique benefits of a space platform. The Canadian Space Agency (CSA) together with Defense Research and Development Canada (DRDC) are planning a micro-satellite platform with a 15 cm telescope dedicated for near space surveillance. The NEOSSat (Near Earth Object Surveillance) spacecraft is expected to be able to detect 20 v magnitude objects with a 100 sec exposure, with a 0.85 deg FOV, on a 1024x1024 CCD, and sub arcsec pointing stability. For detection of NEO small bodies, it will be able to search an area from 45 degrees solar elongation and approximately 40 degrees north to south degrees in elevation. The observation strategy will be optimized to find as many asteroids as possible, based on recent models of asteroid population. Ground based telescopes will also be used to complement follow-ups for orbit determination when possible. The microsatellite is based on the CSA very successful MOST micro-satellite, operating since 2003. Baselined for launch in 2010, the NEOSSat is a shared project with DRDC to demonstrate the technology of an inexpensive space platform to detect High Earth Orbit (HEOSS) earth-orbiting satellites and debris.

SPEX (Spectropolarimeter for Planetary EXploration) is an innovative, compact remote-sensing instrument for detecting and characterizing aerosols. With its 1-liter volume it is capable of full linear spectropolarimetry, without moving parts. High precision polarimetry is performed through encoding the degree and angle of linear polarization of the incoming light in a sinusoidal modulation of the intensity spectrum. This is achieved by using an achromatic quarter-wave retarder, an athermal multiple-order retarder and a polarizing beamsplitter behind each entrance pupil. Measuring a single intensity spectrum thus provides the spectral dependence of the degree and angle of linear polarization. Polarimetry has proven to be an excellent tool to study microphysical properties (size, shape, composition) of atmospheric particles. Such information is essential to better understand the weather and climate of a planet. Although SPEX can be used to study any planetary atmosphere, including the Earth's, the current design of SPEX is tailored to study Martian dust and ice clouds from an orbiting platform: a compact module with 9 entrance pupils to simultaneously measure intensity spectra from 350 to 800 nm, in different directions along the flight direction (including two limb viewing directions). This way, both the intensity and polarization scattering phase functions of dust and cloud particles within a ground pixel are sampled while flying over it. In the absence of significant amounts of dust and clouds, the surface properties can be studied. SPEX provides synergy with instruments on rovers and landers, as it provides a global view of spatial and temporal variations of the planet.

Modern telescopes for space applications use complex optical elements like aspheres or freeforms. For the multispectral pushbroom scanner for spaceborne Earth remote sensing the Jena-Optonik GmbH has developed a Jena-Spaceborne- Scanner JSS product line. The optic of JSS-56 imager is realised by a Three-Mirror-Anastigmat (TMA) telescope designed in aluminium [1]. For brilliant pictures, mirrors with high shape accuracy and very smooth surfaces are required. The combination of precise diamond turning and post polishing techniques enables the classical infrared application for the visible and ultra-violet range. A wide variety of complex mirror shapes are feasible. A special new solution for lightweight design was applied. Ultra precise metal mirrors with aspherical surface are developed at the Fraunhofer IOF from design to system integration. This paper summarizes technologies and results for design, fabrication and surface finish of ultra lightweight aspherical metal mirrors for novel TMA telescopes.

We present our work on the spectral analyser of the Polarimetric and Helioseismic Imager (PHI) instrument to be flown aboard ESA's Solar Orbiter mission. We detail the choices that were made to determine the concept of the spectral analyser, a Lithium Niobate Fabry-Perot interferometer, and its characteristics, as to fulfil both scientific needs and technical requirements. We will present the first experimental results - including stability, repeatability, parallelism, spectral homogeneity and imaging capability - on an air-spaced piezoelectric-tunable etalon, which is the backup solution for PHI.

The Dark UNiverse Explorer (DUNE) is a wide-field imaging mission concept whose primary goal is the study of dark energy and dark matter with unprecedented precision. To this end, DUNE is optimised for weak gravitational lensing, and also uses complementary cosmological probes, such as baryonic oscillations, the integrated Sachs-Wolf effect, and cluster counts. Immediate additional goals concern the evolution of galaxies, to be studied with groundbreaking statistics, the detailed structure of the Milky Way and nearby galaxies, and the demographics of Earth-mass planets. DUNE is a medium class mission consisting of a 1.2m telescope designed to carry out an all-sky survey in one visible and three NIR bands (1deg² field-of-view) which will form a unique legacy for astronomy. DUNE has been selected jointly with SPACE for an ESA Assessment phase which has led to the Euclid merged mission concept.

A well-adapted visible and infrared spectrograph has been developed for the SNAP (SuperNova/Acceleration Probe) experiment proposed for JDEM. The primary goal of this instrument is to ensure the control of Type Ia supernovae. The spectrograph is also a key element for calibration and is able to measure redshift of some thousands of galaxy spectra both in visible and IR. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented. We present the current design and expected performances. We show that with the current optimization and the proposed technology, we expect the most sensitive instrument proposed on this kind of mission. We recall the readiness of the concept and of the slicer technology thanks to large prototyping efforts performed in France which validate the proposition. This work is supported in France by CNRS/INSU, CNRS/IN2P3 and by the French spatial agency (CNES).

An integral field spectrograph concept has been developed for the SNAP/JDEM(SuperNova/Acceleration Probe) experiment. This spectrograph will be optimized for faint supernovae and galaxies in a 3×6 arsec² at low spectral resolution (R~100) through the wavelength range (0.35-1.7 μm). The integral field method is based on glass image slicer. A prototype of this instrument has been build to validate the concept and prove the optical and functional requirements of the SNAP spectrograph. In this paper, we present the first results of this demonstrator. We describe the demonstrator philosophy, set up and functional performances. We present then the first experimental results obtained in the visible range. We validate the slicer optical quality through a set of measurements: PSF, optical losses.

Dark matter in a universe dominated by a cosmological constant seeds the formation of structure and is the scaffolding for galaxy formation. The nature of dark matter remains one of the fundamental unsolved problems in astrophysics and physics even though it represents 85% of the mass in the universe, and nearly one quarter of its total mass-energy budget. The mass function of dark matter "substructure" on sub-galactic scales may be enormously sensitive to the mass and properties of the dark matter particle. On astrophysical scales, especially at cosmological distances, dark matter substructure may only be detected through its gravitational influence on light from distant varying sources. Specifically, these are largely active galactic nuclei (AGN), which are accreting super-massive black holes in the centers of galaxies, some of the most extreme objects ever found. With enough measurements of the flux from AGN at different wavelengths, and their variability over time, the detailed structure around AGN, and even the mass of the super-massive black hole can be measured. The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) is a mission concept for a 1.5-m near-UV through near-IR space observatory that will be dedicated to frequent imaging and spectroscopic monitoring of ~100 multiply-imaged active galactic nuclei over the whole sky. Using wavelength-tailored dichroics with extremely high transmittance, efficient imaging in six channels will be done simultaneously during each visit to each target. The separate spectroscopic mode, engaged through a flip-in mirror, uses an image slicer spectrograph. After a period of many visits to all targets, the resulting multidimensional movies can then be analyzed to a) measure the mass function of dark matter substructure; b) measure precise masses of the accreting black holes as well as the structure of their accretion disks and their environments over several decades of physical scale; and c) measure a combination of Hubble's local expansion constant and cosmological distances to unprecedented precision. We present the novel OMEGA instrumentation suite, and how its integrated design is ideal for opening the time domain of known cosmologically-distant variable sources, to achieve the stated scientific goals.

DUNE (Dark Universe Explorer) is a proposed mission to measure parameters of dark energy using weak gravitational lensing The particular challenges of both optical and infrared focal planes and the DUNE baseline solution is discussed. The DUNE visible Focal Plane Array (VFP) consists of 36 large format red-sensitive CCDs, arranged in a 9x4 array together with the associated mechanical support structure and electronics processing chains. Four additional CCDs dedicated to attitude control measurements are located at the edge of the array. All CCDs are 4096 pixel red-enhanced e2v CCD203-82 devices with square 12 μm pixels, operating from 550-920nm. Combining four rows of CCDs provides a total exposure time of 1500s. The VFP will be used in a closed-loop system by the spacecraft, which operates in a drift scan mode, in order to synchronize the scan and readout rates. The Near Infrared (NIR) FPA consists of a 5 x 12 mosaic of 60 Hawaii 2RG detector arrays from Teledyne, NIR bandpass filters for the wavelength bands Y, J, and H, the mechanical support structure, and the detector readout and signal processing electronics. The FPA is operated at a maximum temperature of 140 K for low dark current of 0.02-/s. Each sensor chip assembly has 2048 x 2048 square pixels of 18 μm size (0.15 arcsec), sensitive in the 0.8 to 1.7 μm wavelength range. As the spacecraft is scanning the sky, the image motion on the NIR FPA is stabilized by a de-scanning mirror during the integration time of 300 s per detector. The total integration time of 1500 seconds is split among the three NIR wavelengths bands. DUNE has been proposed to ESA's Cosmic Vision program and has been jointly selected with SPACE for an ESA Assessment Phase which has led to the joint Euclid mission concept.

Wide Field Camera 3 (WFC3) is a powerful UV/visible/near-infrared camera that has just completed development for installation into the Hubble Space Telescope during upcoming Servicing Mission 4. WFC3 provides two imaging channels. The UVIS channel incorporates a 4102 × 4096 pixel CCD focal plane with sensitivity from 200 to 1000 nm and a 162 × 162 arcsec field of view. The UVIS channel features unprecedented sensitivity and field of view in the near ultraviolet for HST, as well as a rich filter set that complements the visible capabilities of the HST/Advanced Camera for Surveys, whose repair will be attempted in the Servicing Mission. The IR channel features a 1024 × 1024 pixel HgCdTe focal plane covering 850 to 1700 nm with a 136 × 123 arcsec field of view, providing a major advance in IR survey efficiency for HST. We report here on the design of the instrument, on recent activities that have completed the integration of the instrument for flight, and on results of the ground test and calibration program.

Wide Field Camera 3 is the next generation of Hubble Space Telescope imaging instruments. Designed to complement and extend the existing capabilities of the HST, WFC3 will provide large increases in scientific performance in the near ultraviolet and near infrared wavelength regions. This paper describes the scientific capabilities of WFC3, provides a projection of its anticipated scientific performance, and discusses the plans for on-orbit testing and calibration during the Servicing Mission Orbital Verification period.

Formation flying opens new perspectives in solar physics, and allow to conceive giant, externally-occulted coronagraphs using a two-component space system with the external occulter on one spacecraft and the optical instrument on the other spacecraft at a distance of hundred meters. Conditions close to those of a solar total eclipse can then be achieved offering the capability of imaging the solar corona down to the limb at very high spatial resolution. ASPIICS (Association de Satellites Pour l'Imagerie et l'Interférométrie de la Couronne Solaire) is a mission proposed to ESA in the framework of its PROBA-3 demonstration program of formation flying which is presently in phase A. ASPIICS is a single coronagraph which will perform both high spatial resolution imaging of the solar corona as well as 2-dimensional spectroscopy of several emission lines from the coronal base out to 3 R&beye; using a Fabry-Pérot étalon interferometer. The classical design of an externally-occulted coronagraph is adapted to the formation flying configuration allowing the detection of the very inner corona as close as 0.01 R&beye; from the solar limb. Super-ASPIICS is an even more ambitious instrument part of the scientific payload of HiRise, the High Resolution Imaging and Spectroscopy Explorer proposed to ESA in the framework of its Cosmic Vision program. With an increased inter-satellite distance of 280 m, an aperture of 300 mm, a spectral domain extending from the ultraviolet to the near-infrared, and spectroscopic capabilities, Super-ASPIICS will offer unprecedented diagnostic capabilities, including the measurement of coronal magnetic fields.

Since 11 years SOHO-LASCO coronagraphs are producing a unique set of the Sun corona images in the 2-32 solar radius range. For the first time a complete set of coronal calibrated images in WL (polarized and unpolarized) for the full solar cycle is available. The telescopes are equipped with 3 polarizers at -60,0 and 60 degrees, one all pass channel and a set filters. Ground calibrations were completed with in orbit calibrations. To control the evolution of sensivity for each bandpass and for each polarizer, the LASCO-C2 and LASCO-C3 coronographs were provided with an internal system of calibration in orbit. The measures obtained in 1996 and 2003 have been used to determine the CCD flat field for each filter bandpass, the gain constant (ADU to phe^- conversion) and the polarizers transmittance map. The solar corona itself was also used to control the local response. Spacecraft rotations by 45 and 90 complete the test, and allowed for a ultimate but relevant global correction of the polarized images.

A four-quadrant phase-mask (FQPM) coronagraph can suppress perfectly stellar light when a star can be regarded as a point-like source. However, the FQPM coronagraph is highly sensitive to partially resolved stars, and shows second-order sensitivity to tip-tilt error leakage. Higher-order sensitivity is required for extremely high-contrast imaging of nearby stars. We propose an eight-octant phase-mask (EOPM) for achieving fourth-order sensitivity to tip-tilt errors. We manufactured the phase-mask utilizing a nematic liquid crystal (LC) device, which is composed of eight segments. A phase retardation of the LC can be adjustable by an applied voltage to the device. The LC phase-mask can be switched between FQPM-mode and EOPM-mode by applying appropriate voltages to the segments. We carry out experiments on the phase-mask coronagraph with various tip-tilt errors. The experimental results show the higher-order behavior of the EOPM compared to the FQPM. We present a current status of the laboratory experiments on the EOPM coronagraph, and also show coronagraphic performance of the EOPM derived from numerical simulations.

Externally occulted coronagraphs have garnered widespread attention as a potentially viable approach to starlight suppression to enable direct detection and characterization of exo-solar terrestrial planets. Externally occulted coronagraphs consist of a large mask (occulter) in front of the telescope as compared to an internal coronagraph which performs all suppression within the telescope system using combinations of pupil and/or focal plane masks. The advantages of external over internal are that the (i) inner working angle (IWA) is nearly independent of wavelength and (ii) diffracted light is suppressed prior to the telescope; allowing science over a wide spectral band with a conventional telescope with little or no wavefront control. For an internal coronagraph the IWA generally increases with wavelength and scattered/diffracted light levy exquisite tolerances on wavefront, amplitude and polarization errors. An external coronagraph comes with the added complexity and expense of requiring two spacecraft, flying in formation, at separation distances of tens of thousands of kilometers. Re-targeting requires flying one or both spacecraft and aligning them to the target star and hence added fuel and time as well as closed-loop control between them. One approach may be to construct a smaller occulter possibly at closer distances and use it in series with a simple internal coronagraph, i.e. a hybrid, approach. This may simplify requirements on the external occulter but requires more precise tolerances on the telescope system. The question remains as to whether an acceptable balance between the two approaches exists. Herein we look at one approach to designing a hybrid occulter system.

The Transit Characterization Explorer (Tracer) is Small Explorer (SMEX) class mission that would characterize the properties of exoplanets that transit their parent star. Tracer will measure the physical conditions, chemistry dynamics and cloud properties of exoplanet atmospheres. Tracer will detect unseen terrestrial planets by observing them directly in transit or by detecting them via perturbations of transit timings. Tracer will return transit light curves that provide robust radii estimates, and can detect planetary rings and/or satellites. Tracer is an ideal SMEX mission presenting the opportunity for timely exploitation of discoveries from the rapid growth of ground-based surveys for transiting systems and providing the ideal complement to missions such as JWST.

There are good reasons for extending the spectral range of observation to shorter wavelengths than currently envisaged for terrestrial planet-finding missions utilizing a 4-m, diffraction-limited, optical telescope. The angular resolution at shorter wavelengths is higher, so that the image of an exoplanet is better separated from that of the much brighter star. Due to the higher resolution, the exozodiacal background per resolution element is smaller, so exposure times are reduced for the same incident flux. Most importantly, the sensitivity to the presence of life on habitable exoplanets is increased over a hundred-fold by access to the ozone biomarker in the mid-ultraviolet. These benefits must be weighed against challenges arising from the faintness of exoplanets in the mid-UV. Here, we describe the benefits, technical challenges and some proposed solutions for detecting ozone in the atmospheres of Earth-like exoplanets.

We calculate the expected signal-to-noise ratio (SNR) for spectral features in the transit spectrum of an Earth-like exoplanet, for the case of the nearest likely transit of a G and an M star, for a 6-m telescope in space. We find that the SNR values for all important spectral features, in the visible and infrared, are in the range 0.2 to 1.1, making the detection of such features difficult.

We present a method of the polarization degree analysis of exoplanets' objective-prism spectra. The polarization analysis of the objective spectra can be used for discerning planet signal from noisy stellar light. The light reflected from the planet is expected to be partially polarized, while the direct stellar light can be considered to be unpolarized. For measuring objective spectra we use a four-quadrant polarization mask (FQPoM) coronagraph and a prism. The primary suppression of starlight is achieved by destructive interference of the light passing through the central region of FQPoM. For further suppression of starlight we use a polarization differential technique. By taking the difference between two orthogonally polarized components of incoming light we can further suppress unpolarized starlight and reveal the spectrum of the exoplanet. However, when the intensity contrast between the star and its planet is high, the starlight noise impedes detection of the planetary spectrum. The analysis of the degree of polarization relieves the separation of the planetary spectrum from the stellar noise. Moreover, any peculiar features in the objective spectra would be useful to find out the location of the exoplanet. We obtained the experimental results under an intensity contrast of 3.5×10^-5 and an angular separation of 4.9 λ/D.

Perhaps the most compelling piece of science and exploration now under discussion for future space missions is the direct study of planets circling other stars. Indirect means have established planets as common in the universe but have given us a limited view of their actual characteristics. Direct observation holds the potential to map entire planetary systems, view newly forming planets, find Earth-like planets and perform photometry to search for major surface features. Direct observations will also enable spectroscopy of exoplanets and the search for evidence of simple life in the universe. Recent advances in the design of external occulters - starshades that block the light from the star while passing exoplanet light - have lowered their cost and improved their performance to the point where we can now envision a New Worlds Observer that is both buildable and affordable with today's technology. In this paper we explore the comparison of scientific capability of external occulters relative to indirect means and to internal coronagraph missions. We conclude that external occulters logically provide the architecture for the next space mission for exoplanet studies.

The New Worlds Observer (NWO) is a mission concept for the detection and characterization of extra-solar planets. It employs an external starshade and a space telescope. The starshade suppressed the parent star's light making detection of the extra-solar planet possible. This paper formulates system performance based on fundamental systems parameters and explores their interaction.

In this paper, we present methods for constructing design reference missions (DRMs) for space-borne telescopes for the direct detection and characterization of extra-solar planets. Unlike most existing DRMs, which present results based on an assumed fixed rate for the occurrence of extra-solar planets, we calculate the approximate distribution of mission results conditional on the distribution of planets. We also improve on previous models by incorporating optimal integration time modeling that allows for the setting of desired missed-detection and false-alarm probabilities, and by optimizing re-visit timing for systems with and without initial visit detections. Sample DRMs are constructed and evaluated for a telescope with an internal coronagraph, an external occulter, and a hybrid design composed of both elements.

This paper presents analysis showing the sensitivity of the hypergaussian starshade to various types of errors. These errors are defined and classified. Using a single exemplar of the starshade the sensitivity to various kinds of errors, the kind now envisioned for the New Worlds Observer mission. After review of the basics of starshade diffraction, the error classes are defined. The errors include, static errors in global shape, correlated errors, being the same on all petals, and uncorrelated errors, the errors being unique to each petal edge. The effects of the first two classes of errors are evaluated using computerized numerical solutions to the diffraction problem. In the case of uncorrelated errors, a statistical approach is taken.

As currently envisioned, New Worlds Observer is a NASA flagship class mission, designed to fulfill the Terrestrial Planet Finding mission objectives with a much more flexible architecture than the current TPF design concepts. In this paper, we discuss the scalability of NWO for a variety of telescope sizes and briefly discuss the associated science capability. In particular, the paper will address in detail three mission categories: medium, large, and future mission concepts. Medium missions are missions with life cycle costs under $600 million dollars, including a version of NWO that may potentially fit within a MIDEX budget. Large missions are flagship missions that involve significant science returns on a Observatory class level; this is our current realization of NWO for the TPF mission. Future concepts use the NWO architecture, in conjunction with enabling technologies such as in-space servicing, to solve long-term NASA missions such as Lifefinder and Planet Imager. We present a multi-starshade NWO architecture designed for launch on an Ares V launch vehicle as an example of a future concept.

The internal coronagraph and the external occulter have both been proposed for imaging extrasolar planets; each has its own strengths and weaknesses. Internal coronagraphs require very accurate wavefront control, while occulters require accurate positioning and alignment, and a precisely manufactured shape. A hybrid occulter, which combines the two technologies, ideally reduces the tolerances on each, making both sytems more manufacturable. Our hybrid occulter concept combines the apodized pupil Lyot coronagraph with an external occulter. We present a number of designs which cover a wide span of suppression levels, and give a framework for creating further families of occulters with desired potential science bandwidths, occulter angular sizes, and diameters of the telescope secondary. All of these designs are capable of reaching 10¹⁰ contrast over their entire spectrum of design. We also characterize the edge tolerances required for both systems.

The Pupil mapping Exoplanet Coronagraphic Observer (PECO) mission concept is a 1.4-m telescope aimed at imaging and characterizing extra-solar planetary systems at optical wavelengths. The coronagraphic method employed, Phase-Induced Amplitude Apodization or PIAA (a.k.a. pupil mapping) can deliver 1e-10 contrast at 2 lambda/D and uses almost all the starlight that passes through the aperture to maintain higher throughput and higher angular resolution than any other coronagraph or nuller, making PECO the theoretically most efficient existing approach for imaging extra-solar planetary systems. PECO's instrument also incorporates deformable mirrors for high accuracy wavefront control. Our studies show that a probe-scale PECO mission with 1.4 m aperture is extremely powerful, with the capability of imaging at spectral resolution R≈∠15 the habitable zones of already known F, G, K stars with sensitivity sufficient to detect planets down to Earth size, and to map dust clouds down to a fraction of our zodiacal cloud dust brightness. PECO will acquire narrow field images simultaneously in 10 to 20 spectral bands covering wavelengths from 0.4 to 1.0 μm and will utilize all available photons for maximum wavefront sensing and imaging/spectroscopy sensitivity. This approach is well suited for low-resolution spectral characterization of both planets and dust clouds with a moderately sized telescope. We also report on recent results obtained with the laboratory prototype of a coronagraphic low order wavefront sensor (CLOWFS) for PIAA coronagraph. The CLOWFS is a key part of PECO's design and will enable high contrast at the very small PECO inner working angle.

CALISTO, the Cryogenic Aperture Large Infrared Space Telescope Observatory, will enable extraordinarily high sensitivity far-infrared continuum and moderate (R ~ 1000) resolution spectroscopic observations at wavelengths from ~30µm to ~300 μm - the wavelengths between those accessible by JWST and future ground based facilities. CALISTO's observations will provide vital information about a wide range of important astronomical questions including (1) the first stars and initial heavy element production in the universe; (2) structures in the universe traced by H2 emission; (3) the evolution of galaxies and the star formation within them (4) the formation of planetary systems through observations of protostellar and debris disks; (5) the outermost portions of our solar system through observations of Trans-Neptunian Objects (TNOs) and the Oort cloud. With optics cooled to below 5 K, the photon fluctuations from the astronomical background (Zodiacal, Galactic, and extragalactic) exceed those from the telescope. Detectors with a noise equivalent power below that set by the background will make possible astronomical-background-limited sensitivity through the submillimeter/far-infrared region. CALISTO builds on studies for the SAFIR (Single Aperture Far Infrared) telescope mission, employing a 4m x 6m off-axis Gregorian telescope which has a simple deployment using an Atlas V launch vehicle. The unblocked telescope with a cold stop has minimal sidelobes and scattering. The clean beam will allow astronomical background limited observations over a large fraction of the sky, which is what is required to achieve CALISTO's exciting science goals. The maximum angular resolution varies from 1.2" at 30 µm to 12" at 300 μm. The 5σ 1 hr detectable fluxes are ▵S(dν/ν = 1.0) = 2.2x10^-20 Wm^-2, and ▵S(dν/ν = 0.001) = 6.2x10^-22 Wm^-2. The 8 beams per source confusion limit at 70 μm is estimated to be 5 μJy. We discuss CALISTO optics, performance, instrument complement, and mission design, and give an overview of key science goals and required technology development to enable this promising far IR/submm mission.

A key component of our 2008 NASA Astrophysics Strategic Mission Concept Study entitled "An Advanced Technology Large-Aperture Space Telescope: A Technology Roadmap for the Next Decade" is the identification of the astrophysics that can be uniquely accomplished using a filled, large-aperture UV/optical space telescope with an angular resolution 5 - 10 times better than JWST. We summarize here four research areas that are amongst the prime drivers for such an advanced astronomical facility: 1) the detection of habitability and bio-signatures on terrestrial mass exoplanets, 2) the reconstruction of the detailed history of the assembly of stellar mass in the local universe, 3) establishing the mass function and characterizing the accretion environments of supermassive black holes out to redshifts of z ~ 7, and 4) the precise determination of growth of structure in the universe by kinematic mapping of the dark matter halos of galaxies as functions of time and environment.

The planned Ares V launch vehicle with its 10 meter fairing shroud and 55,000 kg capacity to the Sun Earth L2 point enables entirely new classes of space telescopes. NASA MSFC has conducted a preliminary study that demonstrates the feasibility of launching a 6 to 8 meter class monolithic primary mirror telescope to Sun-Earth L2 using an Ares V. Specific technical areas studied included optical design; structural design/analysis including primary mirror support structure, sun shade and secondary mirror support structure; thermal analysis; launch vehicle performance and trajectory; spacecraft including structure, propulsion, GN&C, avionics, power systems and reaction wheels; operations & servicing; mass and power budgets; and system cost.

The response to the ESA Cosmic Vision 2015-2025 Call for Proposals has confirmed a strong interest in the scientific community for far-IR and sub-mm space science missions. Such missions would build on the heritage of projects such as ISO, Akari, Planck, Herschel and Spitzer, with even more demanding requirements and ambitious science goals. The paper, based on the results obtained during two ESA Technology Reference Studies, analyses the requirements of mission studies such as the Far IR Interferometer and the Cosmic Microwave Polarisation Mapper, identifying the main technical challenges and critical technology developments required in order to achieve an adequate level of technology readiness in the future.

VSOP-2 project is a next generation Space-VLBI project approved in Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA). The nominal launch of the VSOP-2 spacecraft, ASTRO-G, is planed in FY2012 by a HIIA rocket as the 7th astronomy satellite in ISAS/JAXA. ASTRO-G satellite will employ a 9.23-m off-axis deployable reflector antenna (LDR) with a surface accuracy of 0.4 mm rms and cryogenically cooled receivers at 22, and 43 GHz and passively cooled receivers at 8 GHz in dual-polarization. A major axis of the orbit is 35,000 km, which will yield an angular resolution of 38 micro-arcseconds achievable at 43 GHz. Then VSOP-2 can observe innermost regions of AGN jets and astronomical masers at 10 times higher angular resolution compared to the previous Space-VLBI, VSOP(-1). These are ideal laboratories to experience physical phenomena in extreme conditions, which cannot be made in any laboratories on the earth. A phase-referencing capability of ASTRO-G satellite makes dramatic improvement of sensitivity and astrometric measurements possible. Basic design for the mechanical and thermal parts of ASTRO-G itself is on going. The radio telescope including the LDR is in EM phase. We would present the overview of VSOP-2 project.

The SPACE and DUNE proposals for the ESA Cosmic Vision 2015-2025 have been pre-selected for a Dark Energy Mission. An assessment study was performed in the past few months resulting in a merged mission called EUCLID. The study led to a possible concept for the mission and the payload, paving the way for the industrial studies. I will describe a fully integrated optical design proposed for EUCLID as well as the different steps and difficulties to meet the optical specifications. ESA used the optical design of the telescope, the spectroscopic channel (ex-SPACE), and the space envelope of the visible imaging and NIR photometric channels (ex-DUNE) to derive a tentative mechanical design and related accommodation constraints for EUCLID. Starting with the preliminary design of the DUNE mission for the telescope and instrument, a series of modifications were made to make space for the spectroscopic channel and minimize the weight. The design of DUNE used a 3 mirror telescope of 1.2-m and a dichroic to obtain imaging in both visible and infrared. The design of SPACE, mostly a Durham design, was made of 4 channels each re-imaging a sub-field from the Cassegrain focus of a 2 mirror telescope onto a Digital Micromirror Device (DMD) containing ~2.2 millions micromirrors. A prism spectrograph followed each array. This design was modified to reduce the number of optics and spectrographs, and add an imaging capability. The total field of EUCLID is almost 1 square degree nearly equally split between the spectroscopic and imaging channels.

The Molecular Hydrogen Explorer (H2EX) proposed for the 2015 - 2025 Cosmic Vision Call issued by ESA in 2007 was designed to make surveys of the molecular gas from its first rotational lines in various extragalactic and galactic sites. The design study led to the proposition of a mid-infrared (8 to 29 μm) Imaging Fourier transform Spectrometer (IFTS) making possible integral field spectroscopy on a 20' wide field and a maximum resolution up to 3×10⁴ at 10 μm. To reach this goal, an all-mirror payload was outlined, made of a 1.2m telescope matched to a dual output interferometer, imaging the field on two 1024×1024 Si:As IBC detectors. The payload was designed to re-use the platform developed for the Planck mission. Such a wide field and high spectral resolution IFTS on a large spectral domain can have further applications, with the necessary adaptation to each case, for future large aperture cryogenic telescopes in the mid-infrared, or in the near-infrared behind future ELTs, in a site like Dome C in Antarctica, and out of astronomy, for remote sensing of Earth atmosphere.

The GAME mission concept aims at the very precise measurement of the gravitational deflection of light by the Sun, by means of an optimised telescope operating in the visible and launched in orbit on a small class satellite. The targeted precision on the γ parameter of the Parametrised Post-Newtonian formulation of General Relativity is 10^-6 or better, i.e. one to two orders of magnitude better than the best currently available results. Such precision is suitable to detect possible deviations from the unity value, associated to generalised Einstein models for gravitation, with potentially huge impacts on the cosmological distribution of dark matter and dark energy. The measurement principle is based on the differential astrometric signature on the stellar positions, i.e., based on the spatial component of the effect rather than the temporal component as in the most recent experiments using radio link delay timing. The observation strategy also allows some additional scientific objectives related to other tests of General Relativity and to the study of exo-planetary field, multiple aperture Fizeau interferometer, observing simultaneously two regions close to the Solar limb. The diluted optics approach is selected for achieving an efficient rejection of the scattered solar radiation, while retaining an acceptable angular resolution on the science targets. We describe the science motivation, the proposed mission profile, the possible payload implementation and the expected performance.

Although the Space Infrared Interferometric Telescope (SPIRIT) was studied as a candidate NASA Origins Probe mission, the real world presents a broader set of options, pressures, and constraints. Fundamentally, SPIRIT is a far-IR observatory for high-resolution imaging and spectroscopy designed to address a variety of compelling scientific questions. How do planetary systems form from protostellar disks, dousing some planets in water while leaving others dry? Where do planets form, and why are some ice giants while others are rocky? How did high-redshift galaxies form and merge to form the present-day population of galaxies? This paper takes a pragmatic look at the mission design solution space for SPIRIT, presents Probe-class and facility-class mission scenarios, and describes optional design changes. The costs and benefits of various mission design alternatives are roughly evaluated, giving a basis for further study and to serve as guidance to policy makers.

ACCESS (Actively-Corrected Coronagraph for Exoplanet System Studies) develops the science and engineering case for an investigation of exosolar giant planets, super-earths, exo-earths, and dust/debris fields that would be accessible to a medium-scale NASA mission. The study begins with the observation that coronagraph architectures of all types (other than the external occulter) call for an exceptionally stable telescope and spacecraft, as well as active wavefront correction with one or more deformable mirrors (DMs). During the study, the Lyot, shaped pupil, PIAA, and a number of other coronagraph architectures will all be evaluated on a level playing field that considers science capability (including contrast at the inner working angle (IWA), throughput efficiency, and spectral bandwidth), engineering readiness (including maturity of technology, instrument complexity, and sensitivity to wavefront errors), and mission cost so that a preferred coronagraph architecture can be selected and developed for a medium-class mission.

We proposed a novel method based on a pre-optics setup that behaves partly as a low-efficiency coronagraph, and partly as a high-sensitivity wavefront aberration compensator (phase and amplitude). The combination of the two effects results in a highly accurate corrected wavefront. First, an (intensity-) unbalanced nulling interferometer (UNI) performs a rejection of part of the wavefront electric field. Then the recombined output wavefront has its input aberrations magnified. Because of the unbalanced recombination scheme, aberrations can be free of phase singular points (zeros) and can therefore be compensated by a downstream phase and amplitude correction (PAC) adaptive optics system, using two deformable mirrors. In the image plane, the central star's peak intensity and the noise level of its speckled halo are reduced by the UNI-PAC combination: the output-corrected wavefront aberrations can be interpreted as an improved compensation of the initial (eventually already corrected) incident wavefront aberrations. The important conclusion is that not all the elements in the optical setup using UNI-PAC need to reach the lambda/10000 rms surface error quality. In the experiments, we observed the aberration magnification of more than 5 times and compensated to about lambda/70 rms which is the current limit of the AO system. This means that we reached to lambda/350 level virtually. We observed the speckle reduction in the focal plane with a coronagraph.

The baseline wavefront sensing and control for James Webb Space Telescope (JWST) includes the Dispersed Hartmann Sensors (DHS) for segment mirror coarse phasing. The two DHS devices, residing on the pupil wheel of the JWST's Near Infrared Camera (NIRCam) Short Wavelength Channel (SWC), can sense the JWST segment mirror pistons by measuring the heights of 20 inter-segment edges from the dispersed fringes. JWST also incorporates two identical grisms in the NIRCam's Long Wavelength Channel (LWC). The two grisms, designed as the Dispersed Fringe Sensor (DFS), are used as the backup sensor for JWST segment mirror coarse phasing. The versatility of DFS enables a very flexible JWST segment coarse phasing process and the DFS is designed to have larger piston capture range than that of DHS, making the coarse phasing more robust. The DFS can also be a useful tool during JWST ground integration and test (I&T). In this paper we describe the DFS design details and use the JWST optical model to demonstrate the DFS coarse phasing process during flight and ground I&T.

A number of upcoming astrophysical investigation concepts are based on large aperture spaceborne telescopes. The basic science goals drive the required aperture to gather sufficient resolution and signal for reasonable integrations to complete their planned design reference missions. In addition, certain fundamental requirements may dictate whether or not a monolithic aperture is required or a segmented mirror array is acceptable. The operating temperature and required performance (absolute and stability over time) are other important drivers. Based on such performance requirements a number of mirror manufacturing trades can be performed to balance the technical performance, cost, and schedule. We will discuss some of the overarching architectural and material trades along with particular manufacturing processes (and their related step functions) that are integral to selecting primary mirror approaches. We will include examples ranging from a few meters up to 16 meters which can be packaged into existing launch shrouds or in significantly expanded future resources such as the Ares V.

Future space telescope programs need to assess in-space robotic assembly of large apertures at GEO and ESL2 to support ever increasing aperture sizes. Since such large apertures will not fit within a fairing, they must rely on robotic assembly/deployment. Proper assessment requires hardware-in-the-loop testing in a representative environment. Developing, testing, and flight qualifying the myriad of technologies needed to perform such a test is complex and expensive using conventional means. Therefore, the objective of the ALMOST program is to develop a methodology for hardware-in-the-loop assessment of in-space robotic assembly of a telescope under micro-gravity conditions in a more cost-effective and risk-tolerant manner. The approach uses SPHERES, currently operating inside ISS, to demonstrate inspace robotic assembly of a telescope that will phase its primary mirror to optical tolerances to compensate for assembly misalignment. Such a demonstration, exploiting the low cost and risk of SPHERES, will dramatically improve the maturity of the guidance, navigation and control algorithms, as well as the mechanisms and concept of operations, needed to properly assess such a capability.

The future of space telescopes lies in large, lightweight, segmented aperture systems. Segmented apertures eliminate manufacturability and launch vehicle fairing diameter as apertures size constraints. Low areal density, actuated segments allow the systems to meet both launch mass restrictions and on-orbit wavefront error requirements. These systems, with silicon carbide as a leading material, have great potential for increasing the productivity, affordability, and manufacturability of future space-based optical systems. Thus far, progress has been made on the manufacturing, sensing, actuation, and on-orbit control of such systems. However, relatively little attention has been paid to the harsh environment of launch. The launch environment may dominate aspects of the design of the mirror segments, with survivability requirements eliminating many potentially good designs. Integrated modeling of a mirror segment can help identify trends in mirror geometries that maximize launch performance, ensuring survivability without drastically over designing the mirror. A finite element model of a single, ribbed, actuated, silicon carbide mirror segment is created, and is used to develop a dynamic, state-space model, with launch load spectra as disturbance inputs, and mirror stresses as performance outputs. The parametric nature of this model allows analysis of many geometrically different mirror segments, helping to identify key parameters for launch survival. The modeling method described herein will enable identification of the design decisions that are dominated by launch, and will allow for development of launch-load alleviation techniques to further push the areal density boundaries in support of the creation of larger and lighter mirrors than previously possible.

Photons weigh nothing. Why must even small space telescopes weigh tons? Primary mirrors require sub-wavelength figure (shape) error in order to achieve acceptable Strehl ratios. Traditional telescopy methods require rigid and therefore heavy mirrors and reaction structures as well as proportionally heavy and expensive spacecraft busses and launch vehicles. Our team's vision is to demonstrate the technology for making giant space telescopes with 1/2000 the areal density of the Hubble. Progress on a novel actuation approach is presented. The goal is to lay groundwork to achieve a 10 to 100 fold improvement in spatial resolution and a factor of 10 reduction in production and deployment cost of active optics. This entailed the synthesis and incorporation of photoactive isomers into crystals and polyimides to develop nanomachine laser controlled molecular actuators. A large photomechanical effect is obtained in polymers 10-50 μm thick. Laser-induced figure variations include the following: 1) reversible bi-directional bending; 2) large deformation range; 3) high speed deformation; and 4) control with a single laser (~0.1 W/cm²). Photolyzation data presented showing reversible semi-permanence of the photoisomerization indicates that a scanned 1 watt laser rather than a megawatt will suffice for large gossamer structure actuation. Areal density can be reduced by increasing actuation. Making every molecule of a substrate an actuator approaches the limit of the design trade space. Presented is a photomechanical system where nearly every molecule of a mirror substrate is itself an optically powered actuator. Why must even small space telescopes weigh tons? Data suggests they need not.

The Kepler instrument is designed to detect Earth size planets in the "habitable zone" orbiting 9