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The optical microscope onboard the Phoenix spacecraft has returned color images (4 μm pixel-1) of soils that were delivered to and held on various substrates. A preliminary taxonomy of Phoenix soil particles, based on color, size, and shape, identifies the following particle types [generic names in brackets]: (1) reddish fines, mostly unresolved, that are spectrally similar to (though slightly darker than) global airborne dust [red fines], (2) silt- to sand-sized brownish grains [brown sand], (3) silt- to sand-sized black grains [black sand], and (4) small amounts of whitish fines, possibly salts [white fines]. Most particles have a saturation magnetization in the range 0.5-2 Am2 kg-1 as inferred from their interaction with magnetic substrates. The particle size distribution has two distinct peaks below 10 μm (fines) and in the range 20-100 μm (grains), respectively, and is different from that of ripple soils in Gusev crater. In particular medium to large sand grains appear to be absent in Phoenix soils. Most sand grains have subrounded shape with variable texture. A fractured grain (observed on sol 112) reveals evidence of micrometer-sized crystal facets. The brown sand category displays a large diversity in color including shiny, almost colorless particles. Potential source regions for these grains may be the Tharsis volcanoes or Heimdal crater (20 km east of the landing site). The black grains are suggested to belong to a more widespread population of particles with mafic mineralogy. The absence of black/brown composite grains is consistent with different formation pathways and source regions for each grain type. Copyright 2010 by the American Geophysical Union.

The demonstration of efficient single-mode fiber (SMF) coupling is a key requirement for the development of a compact, ultra-precise radial velocity (RV) spectrograph. iLocater is a next generation instrument for the Large Binocular Telescope (LBT) that uses adaptive optics (AO) to inject starlight into a SMF. In preparation for commissioning iLocater, a prototype SMF injection system was installed and tested at the LBT in the Y-band (0.970-1.065 $\mu$m). This system was designed to verify the capability of the LBT AO system as well as characterize on-sky SMF coupling efficiencies. SMF coupling was measured on stars with variable airmasses, apparent magnitudes, and seeing conditions for six half-nights using the Large Binocular Telescope Interferometer. We present the overall optical and mechanical performance of the SMF injection system, including details of the installation and alignment procedure. A particular emphasis is placed on analyzing the instrument's performance as a function of telescope elevation to inform the final design of the fiber injection system for iLocater., Comment: 11 pages, 7 figures

The current generation of precision radial velocity (RV) spectrographs are seeing-limited instruments. In order to achieve high spectral resolution on 8m class telescopes, these spectrographs require large optics and in turn, large instrument volumes. Achieving milli-Kelvin thermal stability for these systems is challenging but is vital in order to obtain a single measurement RV precision of better than 1m/s. This precision is crucial to study Earth-like exoplanets within the habitable zone. iLocater is a next generation RV instrument being developed for the Large Binocular Telescope. Unlike seeing-limited RV instruments, iLocater uses adaptive optics (AO) to inject a diffraction-limited beam into single-mode fibers. These fibers illuminate the instrument spectrograph, facilitating a diffraction-limited design and a small instrument volume compared to present-day instruments. This enables intrinsic instrument stability and facilitates precision thermal control. We present the current design of the iLocater cryostat which houses the instrument spectrograph and the strategy for its thermal control. The spectrograph is situated within a pair of radiation shields mounted inside an MLI lined vacuum chamber. The outer radiation shield is actively controlled to maintain instrument stability at the sub-mK level and minimize effects of thermal changes from the external environment. An inner shield passively dampens any residual temperature fluctuations and is radiatively coupled to the optical board. To provide intrinsic stability, the optical board and optic mounts will be made from Invar and cooled to 58K to benefit from a zero coefficient of thermal expansion (CTE) value at this temperature. Combined, the small footprint of the instrument spectrograph, the use of Invar, and precision thermal control will allow long-term sub-milliKelvin stability to facilitate precision RV measurements., Comment: 10 pages, 7 figures

Existing planet-finding spectrometers are limited by systematic errors that result from their seeing-limited design. Of particular concern is the use of multi-mode fibers (MMFs), which introduce modal noise and accept significant amounts of background radiation from the sky. We present the design of a single-mode fiber-based acquisition camera for a diffraction-limited spectrometer named “iLocater." By using the “extreme" adaptive optics (AO) system of the Large Binocular Telescope (LBT), iLocater will overcome the limitations that prevent Doppler instruments from reaching their full potential, allowing precise radial velocity (RV) measurements of terrestrial planets around nearby bright stars. The instrument presented in this paper, which we refer to as the acquisition camera “demonstration system," will measure on-sky single-mode fiber (SMF) coupling efficiency using one of the 8.4m primaries of the LBT in fall 2015.

The microscope for the Beagle 2 lander, which was launched as part of the European Space Agency's Mars Express mission on 2 June 2003, will provide images of the Martian surface at around 6 μm resolution. It will provide optical images of the surface of Mars at a resolution 5 times higher than any other experiment currently planned. The device has a working distance of 12 mm and uses a set of 12 light-emitting diodes which surround the aperture to illuminate the sample in four colours. The target is brought into focus using a stepper motor. This article describes the scientific objectives and the design of the microscope. It also discusses initial results from ground calibration exercises which were designed to validate the system and describes aspects of its operation.

Facility Instruments at the Large Binocular Telescope (LBT) include two spectrograph pairs, the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCI), a near-infrared imager and spectrograph pair, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam long-slit spectrographs. Both spectrograph designs utilize focal plane masks for long-slit and multi-slit observations. This paper describes the mask configuration and specification process for each instrument, as well as the steps in mask fabrication, handling, and installation.

Facility Instruments at the Large Binocular Telescope (LBT) include the Large Binocular Camera (LBC), a pair of wide-field imagers at the prime focus, the LUCIFER (or LUCI) near-infrared imager and spectrograph pair, and the Multi-Object Double Spectrograph (MODS), a pair of long-slit spectrographs. The disciplines involved in instrument support are reviewed, as well as scheduling of support personnel. A computerized system for instrument maintenance scheduling and spare parts inventory is described. Instrument problems are tracked via an online reporting system, and statistics on types of instrument problems are discussed, as well as applicability of the system to troubleshooting.

The use of optical fibers to couple spectrographs to telescopes has been important in the search for extrasolar planets using radial velocity measurements. The ability of an optical fiber to partially scramble the input illumination enables a fiber feed to provide more uniform illumination to the spectrograph optics, but a limiting factor in fiber coupling is modal noise. Agitation of the fiber has been shown to reduce modal noise, but altering fiber transmission parameters by varying the length of the fiber may offer advantages. We report on tests comparing some of the alternative devices for reducing modal noise.

The Adaptively Corrected Echelle Spectrograph (ACES) high resolution echelle spectrograph was originally developed at Steward Observatory to couple adaptively-corrected stellar images to the instrument using a near single mode optical fiber to give R~190,000 at V band. We explore here the feasibility of using the spectrograph with the 2x8.4m Large Binocular Telescope (LBT), preserving the fiber coupling for instrument isolation and illumination stability, but employing either a narrow slit or image slicer to offset the smaller component size and thereby preserve high resolution. Such a combination could offer simultaneously higher resolution with greater wavelength coverage per exposure than the configuration of alternate instruments.

The Surface Stereo Imager (SSI), a stereoscopic, multispectral camera on the Mars Polar Lander, is described in terms of its capabilities for studying the Martian polar environment. The camera's two eyes, separated by 15.0 cm, provide the camera with range-finding ability. Each eye illuminates half of a single CCD detector with a field of view of 13.8° high by 14.3° wide and has 12 selectable filters between 440 and 1000 nm. The ƒ/18 optics have a large depth of field, and no focusing mechanism is required; a mechanical shutter is avoided by using the frame transfer capability of the 528×512 CCD. The resolving power of the camera, 0.975 mrad/pixel, is the same as the Imager for Mars Pathfinder camera, of which it is nearly an exact copy. Specially designed targets are positioned on the Lander; they provide information on the magnetic properties of windblown dust, and radiometric standards for calibration. Several experiments beyond the requisite color panorama are described in detail: contour mapping of the local terrain, multispectral imaging of interesting features (possibly with ice or frost in shaded spots) to study local mineralogy, and atmospheric imaging to constrain the properties of the haze and clouds. Eight low-transmission filters are included for imaging the Sun directly at multiple wavelengths to give SSI the ability to measure dust opacity and potentially the water vapor content. This paper is intended to document the functionality and calibration of the SSI as flown on the failed lander.

The Robotic Arm Camera (RAC) is one of the key instruments newly developed for the Mars Volatiles and Climate Surveyor payload of the Mars Polar Lander. This lightweight instrument employs a front lens with variable focus range and takes images at distances from 11 mm (image scale 1:1) to infinity. Color images with a resolution of better than 50 μm can be obtained to characterize the Martian soil. Spectral information of nearby objects is retrieved through illumination with blue, green, and red lamp sets. The design and performance of the camera are described in relation to the science objectives and operation. The RAC uses the same CCD detector array as the Surface Stereo Imager and shares the readout electronics with this camera. The RAC is mounted at the wrist of the Robotic Arm and can characterize the contents of the scoop, the samples of soil fed to the Thermal Evolved Gas Analyzer, the Martian surface in the vicinity of the lander, and the interior of trenches dug out by the Robotic Arm. It can also be used to take panoramic images and to retrieve stereo information with an effective baseline surpassing that of the Surface Stereo Imager by about a factor of 3.

The Mars Pathfinder, Mars Surveyor '98, and Mars Surveyor '01 lander designs all utilize CCD-based cameras to conduct scientific investigations, assist with navigation of surface reverse and/or confirm sample acquisition and delivery by robotic arms. The extreme temperature and pressure environment of the Martian surface, the vibration and shock experienced during launch and landing, and the tight volume, mass, and power budgets challenge the designer and scientist alike to develop instruments and associated electronics that will function properly to provide the desired data. This paper provides an overview of the optical and mechanical design of two of the camera configurations, as well as a detailed description of the camera electronics. The cameras described are a gimbal-mounted stereo multi-spectral imager with 1 mrad/pixel resolution, and a variable focus robotic arm camera capable of 23-/spl mu/m/pixel resolution and provided with a self-contained three-color illumination system. The electronics, housed in the cameras and in separate enclosures, utilizes such subsystems as FPGAs for digital control, VME bus-mapped video memory, and multiplexed stepper motor select/phase driver circuitry.

[1] The Magnetic Properties Experiment (referred to as iSweep or Caltarget) onboard the Phoenix lander was executed in the arctic region of Mars during the mission's 152 sols lifetime. The iSweep experiment involved periodic multispectral imaging of a series of permanent ring magnets. It was designed to attract airborne magnetic dust particles to certain areas on the iSweeps thereby sorting all settling airborne particles at least to some degree according to their magnetic properties. The dust on the area directly above the strong magnets of the iSweep was found to be brighter than that collected on the precursor Sweep Magnet Experiment onboard the Mars Exploration Rovers near Mars' equator, and also this dust is found to be brighter than both surface soil near the lander and soil in the region surrounding the lander. As most other dust and soils on Mars, the Phoenix dust lacks strong spectral signatures of highly crystalline phases. For the first time, based on the complete calibrated data set of images of the iSweeps, spectra were extracted of the putative dust falling on the magnetically protected areas of the iSweeps. These areas are accessible only for particles with a magnetic susceptibility below 10−3. Spectra of this nonmagnetic dust are interpreted as signals from nonmagnetic minerals such as tectosilicates or glasses pigmented by poorly crystalline ferric oxides. Rates of dust settling were determined to be 1.08 μm/sol on the magnets and 0.06 μm/sol for the magnetically protected areas.

The Phoenix microscopy station, designed for the study of Martian dust and soil, consists of a sample delivery system, an optical microscope, and an atomic force microscope. The combination of microscopies facilitates the study of features from the millimeter to nanometer scale. Light-emitting diode illumination allows for full color optical imaging of the samples as well as imaging of ultraviolet-induced visible fluorescence. The atomic force microscope uses an array of silicon tips and can operate in both static and dynamic mode. Copyright 2008 by the American Geophysical Union.

[1] The Phoenix Robotic Arm Camera (RAC) is a variable-focus color camera mounted to the Robotic Arm (RA) of the Phoenix Mars Lander. It is designed to acquire both close-up images of the Martian surface and microscopic images (down to a scale of 23 μm/pixel) of material collected in the RA scoop. The mounting position at the end of the Robotic Arm allows the RAC to be actively positioned for imaging of targets not easily seen by the Stereo Surface Imager (SSI), such as excavated trench walls and targets under the Lander structure. Color information is acquired by illuminating the target with red, green, and blue light-emitting diodes. Digital terrain models (DTM) can be generated from RAC images acquired from different view points. This can provide high-resolution stereo information about fine details of the trench walls. The large stereo baseline possible with the arm can also provide a far-field DTM. The primary science objectives of the RAC are the search for subsurface soil/ice layering at the landing site and the characterization of scoop samples prior to delivery to other instruments on board Phoenix. The RAC shall also provide low-resolution panoramas in support of SSI activities and acquire images of the Lander deck for instrument and Lander check out. The camera design was inherited from the unsuccessful Mars Polar Lander mission (1999) and further developed for the (canceled) Mars Surveyor 2001 Lander (MSL01). Extensive testing and partial recalibration qualified the MSL01 RAC flight model for integration into the Phoenix science payload.

The first NASA scout mission to Mars, Phoenix, launched 4 August will land in the northern part of Mars in the locality of 68°N and 233°E on 25 May 2008. Part, of the science payload is the Magnetic Properties Experiments (MPE) that consists of two main experiments: the Improved Sweep Magnet Experiment (ISWEEP) and 10 sets of two Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) magnet substrates with embedded permanent magnets of different strength. The ISWEEP experiment is, as the name indicates, an improved version of the Sweep Magnet Experiments flown onboard the two Mars Exploration Rovers (MERs) Spirit and Opportunity. The sweep magnet is ring shaped and is designed to allow only nonmagnetic particles to enter a small circular area at the center of the surface of this structure. Results from this experiment have shown that on the MERs hardly any particles can be detected in the central area of this ring-shaped magnet. From this we have concluded that essentially all particles in the Martian atmosphere are magnetic in the sense that they are attracted to permanent magnets. In order to improve the sensitivity of the Sweep Magnet Experiment for detection of nonmagnetic or very weakly magnetic particles, the ISWEEP holds six ring-shaped magnets, somewhat larger than the sweep magnet of the MERs, and with six different background colors in the central area. The six different colors provide new possibilities for improved contrast between these background colors, i.e., any putative nonmagnetic particles should render these more easily detectable. The Surface Stereo Imager will also take advantage of the small clean areas in the ISWEEPs and use the presumably constant colors for radiometric calibration of images. The MECA magnets work as substrates in the MECA microscopy experiments; they are built to attract and hold magnetic particles from dust samples. The collected dust will then be examined by the optical microscope and the atomic force microscope in the MECA package. Copyright 2008 by the American Geophysical Union.

NASA's Phoenix Mars lander employs a suite of instruments to investigate the properties of the planet's North polar region. A Robotic Arm is used to retrieve subsurface samples for analysis, and a Robotic Arm Camera mounted on the wrist of the arm provides images of the surface and of material in the scoop. The RAC and the Optical Microscope both utilize LEDs, which enable the generation of true color imagery and provide higher illumination levels at lower power levels than the incandescent lamps used on a predecessor instrument. Although red, green and blue LEDs were available when the instruments were being developed, the manufacturers had not tested the devices in all the environments the spacecraft would encounter. This paper details the results of a series of tests conducted to qualify the lamps for the temperature, vibration, and radiation environments they would encounter during the mission.

We describe the origin of spectral modal noise in a fiber-coupled spectrograph. Prior investigations of this phenomenon have considered optical fibers with large cores that support thousands of optical modes and used a statistical treatment to analyze spectral noise that arises from interference between the modes. We examine spectral modal noise for a fiber-coupled spectrograph with a smaller-diameter fiber core, optimized for adaptively corrected telescopes, that supports only a few propagating modes for visible and near-infrared light. Simulations to predict the minimum amount of fiber stretch required to shift spectral oscillations by a half-period are confirmed by experiment.

We have previously determined the origin of spectral modal noise (SMN) in a fiber-coupled echelle spectrograph. The Fourier transform is applied to simulated and experimental data to investigate the oscillation frequency components in SMN.

We discuss the origin of spectral modal noise in a fiber-coupled echelle spectrograph for astronomical applications. Computer simulation is used to show how the interference of optical modes in a multi-mode optical fiber leads to a periodic variation in transmission spectra, as observed experimentally.

Radial velocity studies represent the most successful method to date for the detection of extrasolar planets. Although radial velocity (v r ) measurement precision of 3 m s -1 is routinely achieved in some programs, it is important to understand and minimize sources of experimental error. Furthermore, velocity variations resulting from astrophysical processes contribute to velocity errors, and must be removed if precision is to be further improved. The use of spectrographs with telescopes having high order adaptive optics (AO) systems offers the possibility of achieving near diffraction-limited very high spectral resolution at visible wavelengths on ground-based telescopes. The small stellar image diameters obtained with adaptively corrected systems allow high resolution without a large loss of light at the spectrograph entrance aperture. The Adaptively Corrected Echelle Spectrograph (ACES), designed at Steward Observatory for a spectral resolution R ~ 200,000, couples the telescope image to the instrument with an 8-10μm diameter near single-mode optical fiber. The shorter effective slit permits the placement of more echelle orders on the detector after cross dispersion, with a correspondingly greater wavelength coverage per exposure. This simultaneous high resolution and large wavelength coverage can be used to improve the precision of radial velocity studies by improving wavelength calibration, reducing dataset internal errors, and permitting better characterization and removal of effects intrinsic to the stars themselves.

The use of spectrographs with telescopes having high order adaptive optics (AO) systems offers the possibility of achieving near diffraction-limited spectral resolution on ground-based telescopes, as well as important advantages for instrument design. The small stellar image diameters obtained with adaptively corrected systems allow high resolution without a large loss of light at the spectrograph entrance slit, as well as greater spectral coverage per exposure. The adaptively corrected echelle spectrograph (ACES), designed at Steward Observatory for a spectral resolution R ≈ 200,000, couples the telescope pupil to the instrument with a 10 mm diameter near single-mode optical fiber. Initial observations at the 2.5m telescope on Mt. Wilson validated the concept of achieving high spectral resolution with an adaptively corrected telescope and fiber coupled spectrograph. However the transmission of multiple modes in the fiber lead to a wavelength-dependent variation in illumination that made flat fielding impossible. In this paper we describe instrument design improvements, the installation and testing of a new CCD detector, and testing aimed at understanding and eliminating the fiber-related transmission problems to permit science quality imaging.

The Mars Surveyor Spacecraft's Robotic Arm Camera (RAC) is a CCD imager designed to enhance the capability of studyingboth trenched areas and material collected by the craft's Robotic Arm. Because of the wide range of object distances/imagescales desired, an active focus mechanism will be used, capable of imaging from a magnification of 1 : 1 to infinity focus, witha maximum resolution of 23 microns/pixel for Mars surface material samples in the mouth of the scoop. This paper willdiscuss the optomechanical design of the optics, mechanism, and actuator, operational scenarios for the most efficientcollection of the necessary images, and algorithms for selection of images to be returned to earth.Keywords:Optomechanical, camera, autofocus, instrument, Mars 1. INTRODUCTION The Mars Volatiles and Climate Surveyor (MVACS) instrument package to be flown on the Mars SurveyorSpacecraft scheduled for launch in January, 1999, includes a Robotic Arm for collecting and delivering samples to a thermalanalysis instrument. The Robotic Arm Camera, to be mounted at the wrist, will be capable of imaging the contents of thescoop, the interior of the trench and surrounding areas, and even the horizon. Figure 1 .

The Mars Surveyor Spacecraft's Robotic Arm Camera (RAC) is a CCD imager designed to enhance the capability of studyingboth trenched areas and material collected by the spacecraft's Robotic Arm. An active focus mechanism will be used toachieve imaging from a magnification of 1:1 to infinity focus, permitting scenarios ranging from microscopic imaging ofscoop contents with a resolution of 23 microns/pixel to stereo ranging of distant features using a baseline between the RACand another camera on the lander deck. This paper will discuss the optomechanical design of the camera including thestructure, optics, focus mechanism with actuator, windows and moveable optics cover, and integral illumination devicesrequired for imaging the interior of the scoop and trench. Keywords: Optomechanical, camera, instrument, Mars 1. INTRODUCTION The Mars Volatiles and Climate Surveyor (MVACS) instrument package to be flown on the Mars SurveyorSpacecraft scheduled for launch in January, 1999, includes a Robotic Arm for collecting and delivering samples to a thermalanalysis instrument. The Robotic Arm Camera, to be mounted at the wrist, will be capable of imaging the contents of thescoop, the interior of the trench and surrounding areas, and even the horizon. Figure 1. depicts the camera mounted on aprototype arm, and Figure 2 shows the overall dimensions of the camera.