The Herschel-Heterodyne Instrument for the Far-Infrared (HIFI): instrument and pre-launch testing

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

NASA Tech Briefs, November 2004

Topics include: Multifunction Imaging and Spectroscopic Instrument; Position-Finding Instrument Built Around a Magnetometer; Improved Measurement of Dispersion in an Optical Fiber; Probe for Sampling of Interstitial Fluid From Bone; Neuropsychological Testing of Astronauts; Method of Calibration for a Large Cathetometer System; Four-Channel PC/104 MIL-STD-1553 Circuit Board; Improved Method of Locating Defects in Wiring Insulation; Strobe Traffic Lights Warn of Approaching Emergency Vehicles; Improved Timing Scheme for Spaceborne Precipitation Radar; Concept for Multiple-Access Free-Space Laser Communications; Variable Shadow Screens for Imaging Optical Devices; Verifying Diagnostic Software; Initial Processing of Infrared Spectral Data; Activity-Centric Approach to Distributed Programming; Controlling Distributed Planning; New Material for Surface-Enhanced Raman Spectroscopy; Treated Carbon Nanofibers for Storing Energy in Aqueous KOH; Advanced Infant Car Seat Would Increase Highway Safety; Development of Biomorphic Flyers; Second-Generation Six-Limbed Experimental Robot; Miniature Linear Actuator for Small Spacecraft; Process for Making Single-Domain Magnetite Crystals; A New Process for Fabricating Random Silicon Nanotips; Resin-Transfer-Molding of a Tool Face; Improved Phase-Mask Fabrication of Fiber Bragg Gratings; Tool for Insertion of a Fiber-Optic Terminus in a Connector; Nanofluidic Size-Exclusion Chromatograph; Lightweight, Low-CTE Tubes Made From Biaxially Oriented LCPs; Using Redundancy To Reduce Errors in Magnetometer Readings; Compact Instrument for Measuring Profile of a Light Beam; Multilayer Dielectric Transmissive Optical Phase Modulator; Second-Generation Multi-Angle Imaging Spectroradiometer; Real-Time Adaptive Color Segmentation by Neural Networks; Research and Development in Optical Communications; Tests of Multibeam Scintillation Mitigation on Laser Uplinks; and Spaceborne Infrared Atmospheric Sounder

PROPOSED MIDDLEWARE SOLUTION FOR RESOURCE-CONSTRAINED DISTRIBUTED EMBEDDED NETWORKS

The explosion in processing power of embedded systems has enabled distributed embedded networks to perform more complicated tasks. Middleware are sets of encapsulations of common and network/operating system-specific functionality into generic, reusable frameworks to manage such distributed networks. This thesis will survey and categorize popular middleware implementations into three adapted layers: host-infrastructure, distribution, and common services. This thesis will then apply a quantitative approach to grading and proposing a single middleware solution from all layers for two target platforms: CubeSats and autonomous unmanned aerial vehicles (UAVs). CubeSats are 10x10x10cm nanosatellites that are popular university-level space missions, and impose power and volume constraints. Autonomous UAVs are similarly-popular hobbyist-level vehicles that exhibit similar power and volume constraints. The MAVLink middleware from the host-infrastructure layer is proposed as the middleware to manage the distributed embedded networks powering these platforms in future projects. Finally, this thesis presents a performance analysis on MAVLink managing the ARM Cortex-M 32-bit processors that power the target platforms

Implementing Institute of Electrical and Electronics Engineers (IEEE) 802.11 Standard Medium Access Control Protocol for Wireless Local Area Networks (LANS) on a Laboratory Hardware Prototype

Wireless Local Area Networks (LANs) are extremely convenient, flexible, and easy to deploy. All LANs in which multiple hosts must access the same medium use a Medium Access Control (MAC) protocol to coordinate channel access. The MAC is part of the Data Link Layer of the Open Systems Interconnection (OSI) Reference Model. One MAC protocol in extensive use today is the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. Since IEEE 802.11 devices are so prevalent in today s world, many researcher are exploring modifications and enhancements to the protocol. There are several well developed analytical and simulation models for IEEE 802.11 available to researchers, yet one significant obstacle remains: the lack of a means to obtain experimental data based on proposed protocol changes. Without real world experimental data, researchers lack the ability to test out their proposals in a real world environment. To fill this need, this thesis created a hardware prototype from which researchers can obtain experimental data about IEEE 802.11. This hardware prototype can now be used by researchers to gain real world data on their proposed modifications to IEEE 802.11

NASA Tech Briefs, September 2009

opics covered include: Filtering Water by Use of Ultrasonically Vibrated Nanotubes; Computer Code for Nanostructure Simulation; Functionalizing CNTs for Making Epoxy/CNT Composites; Improvements in Production of Single-Walled Carbon Nanotubes; Progress Toward Sequestering Carbon Nanotubes in PmPV; Two-Stage Variable Sample-Rate Conversion System; Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas; Board Saver for Use with Developmental FPGAs; Circuit for Driving Piezoelectric Transducers; Digital Synchronizer without Metastability; Compact, Low-Overhead, MIL-STD-1553B Controller; Parallel-Processing CMOS Circuitry for M-QAM and 8PSK TCM; Differential InP HEMT MMIC Amplifiers Embedded in Waveguides; Improved Aerogel Vacuum Thermal Insulation; Fluoroester Co-Solvents for Low-Temperature Li+ Cells; Using Volcanic Ash to Remove Dissolved Uranium and Lead; High-Efficiency Artificial Photosynthesis Using a Novel Alkaline Membrane Cell; Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays; Micro-Horn Arrays for Ultrasonic Impedance Matching; Improved Controller for a Three-Axis Piezoelectric Stage; Nano-Pervaporation Membrane with Heat Exchanger Generates Medical-Grade Water; Micro-Organ Devices; Nonlinear Thermal Compensators for WGM Resonators; Dynamic Self-Locking of an OEO Containing a VCSEL; Internal Water Vapor Photoacoustic Calibration; Mid-Infrared Reflectance Imaging of Thermal-Barrier Coatings; Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays; Improved Scanners for Microscopic Hyperspectral Imaging; Rate-Compatible LDPC Codes with Linear Minimum Distance; PrimeSupplier Cross-Program Impact Analysis and Supplier Stability Indicator Simulation Model; Integrated Planning for Telepresence With Time Delays; Minimizing Input-to-Output Latency in Virtual Environment; Battery Cell Voltage Sensing and Balancing Using Addressable Transformers; Gaussian and Lognormal Models of Hurricane Gust Factors; Simulation of Attitude and Trajectory Dynamics and Control of Multiple Spacecraft; Integrated Modeling of Spacecraft Touch-and-Go Sampling; Spacecraft Station-Keeping Trajectory and Mission Design Tools; Efficient Model-Based Diagnosis Engine; and DSN Simulator

A systems architecture-based approach to assess candidate upgrades to complex systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2012."September 2012." Cataloged from PDF version of thesis.Includes bibliographical references (p. 163-167).The Compatibility Assessment Method (CAM), a new structured process for assessing compatibility between parent systems and child subsystems is proposed and applied to several cases where subsystems are being replaced in legacy systems. CAM is a screening process intended to be used by project managers who need to replace components of complex systems. The functional model-based process uses an extension of the Integrated Definition Modeling Language of IDEFO. The IDEFO method is used for defining compatibility measures based on each of the four constituent arrows that show inputs, controls, outputs, and mechanisms (ICOM). In this extension, the control constituents are replaced with constraints. Each of the ICOM constituents is expanded with parameters which include metrics and values. The ICOMs with their parameters and metrics are then used to characterize two or more subsystems in a matrix format. The differences between these matrices are entered into the sparse "Delta Matrix" which shows analysts the differences between the systems. These differences can be assigned to the appropriate levels of technical expertise to be analyzed and to determine feasibility of the child subsystem in the parent system. The process is compared to current practices in government unmanned aircraft system program offices to determine the usefulness of adopting this compatibility assessment process. This dissertation outlines the need for and development of the method for application by practitioners responsible for replacing subsystems on legacy systems. The development includes evaluations of the method and an experiment with cohorts of student system engineers to compare the output of the Compatibility Assessment Method to less-structured methods. This research contributes additional insight into system architecting theory and proposes a structured method for practitioners to use to improve the processes to perform part replacement in legacy systems. While others have offered methods to measure aspects of system architecture, this proposed method moves beyond the extant literature with tools for practitioners.by David Scott Andrew Long.Ph.D

Modular, reconfigurable approach for a commercial space spacecraft programme

This thesis presents the work performed in producing a system-level design for a modular, multipurpose small satellite platform. A multipurpose platform may be applied to a wide range of missions, and, to be commercially viable, the envelope of missions for which it is suitable should be as large as possible. The research therefore addresses the particular requirements that are specific to different mission types, and produces characteristic requirement sets for each. General design requirements are also derived, such as those for enabling modularity and allowing compatibility with different launch vehicles. The commercial requirements arising from the different market and customer sectors are also examined. Industry analysis allows identification of general market trends, and predictions are made regarding the likely size and characteristics of the market in which the proposed platform would compete. It is anticipated there could be a worldwide demand for more than twenty small satellites each year, for which a flexible small spacecraft platform could potentially compete. After derivation of the necessary requirements has been performed, a system-level design of the spacecraft platform is undertaken. The resulting design is based on a multi-module, reconfigurable concept, which can be adapted to fit the different launch envelopes of Pegasus-XL, Taurus, ASAP-5 and larger launchers, and also to accommodate a wide range of payloads. The subsystems are offered in different capability variants, which may be interchanged in response to different mission requirements. The platform equipment and structure forms a 'standard parts lisf', from which the appropriate configuration can be built up. Schedule reductions are obtained due to the modular design allowing more of the integration and testing of the platform to be performed in parallel. The proposed programme for development of the platform uses up-front investment to conduct much of the detailed design of the platform in advance of any actual project. This allows the design effort to be shared across many subsequent projects, and the design phase of each new project to be minimised. The key benefits of the proposed platform and programme are adaptability, ability to rapidly reconfigure to mission requirements, suitability for future upgrading, and reduction of the project schedule.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Modular, reconfigurable approach for a commercial space spacecraft programme

This thesis presents the work performed in producing a system-level design for a modular, multipurpose small satellite platform. A multipurpose platform may be applied to a wide range of missions, and, to be commercially viable, the envelope of missions for which it is suitable should be as large as possible. The research therefore addresses the particular requirements that are specific to different mission types, and produces characteristic requirement sets for each. General design requirements are also derived, such as those for enabling modularity and allowing compatibility with different launch vehicles. The commercial requirements arising from the different market and customer sectors are also examined. Industry analysis allows identification of general market trends, and predictions are made regarding the likely size and characteristics of the market in which the proposed platform would compete. It is anticipated there could be a worldwide demand for more than twenty small satellites each year, for which a flexible small spacecraft platform could potentially compete. After derivation of the necessary requirements has been performed, a system-level design of the spacecraft platform is undertaken. The resulting design is based on a multi-module, reconfigurable concept, which can be adapted to fit the different launch envelopes of Pegasus-XL, Taurus, ASAP-5 and larger launchers, and also to accommodate a wide range of payloads. The subsystems are offered in different capability variants, which may be interchanged in response to different mission requirements. The platform equipment and structure forms a 'standard parts lisf', from which the appropriate configuration can be built up. Schedule reductions are obtained due to the modular design allowing more of the integration and testing of the platform to be performed in parallel. The proposed programme for development of the platform uses up-front investment to conduct much of the detailed design of the platform in advance of any actual project. This allows the design effort to be shared across many subsequent projects, and the design phase of each new project to be minimised. The key benefits of the proposed platform and programme are adaptability, ability to rapidly reconfigure to mission requirements, suitability for future upgrading, and reduction of the project schedule.EThOS - Electronic Theses Online ServiceGBUnited Kingdo