570 research outputs found

    Exploration of the use of digital micromirror devices for highly multiplexed spectroscopy applications in astronomy

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    Highly multiplexed spectroscopic capabilities are critical to future astronomy space missions. Such capabilities enable large samples of spectral data to be collected in an efficient manner. The individual mirrors of a Digital Micromirror Device (DMD) can serve as slits in a multi-object spectrograph (MOS). This work explores several areas vital to the inclusion of DMDs in future astronomy missions: space qualification, optical performance, and the implementation of Hadamard Transform Spectral Imaging (HTSI). While DMDs were not designed for space, this work reports on testing that demonstrates that the devices can withstand the environmental conditions of a space mission. The optical properties of a DMD ultimately drive the wavelength range and quality of spectral data obtained from a DMD-based MOS. We have characterized the reflectance and contrast ratio of various DMDs from near ultra-violet through visible wavelengths and discuss the results. This work also discusses efforts in expanding the spectral sensitivity of DMDs. Maximizing spectral information over a spatial field of view (FoV) on the sky is highly desirable. In the multi-object spectroscopy mode, individual DMD micromirrors are selected to generate a sparse sample of spectra at individual locations. Additionally, a DMD can be used for integral field spectroscopy (IFS) by forming a long slit from a line of micromirrors, which is then altered to effectively scan across the FoV. In this work we evaluate an alternative technique, HTSI. HTSI has the advantage of a gain in signal-to-noise ratio (SNR) as compared to direct measurements with a long slit, when the observed signals are not photon-noise dominated. We have simulated the performance of HTSI with a DMD-based MOS to identify the limitations of the technique and scenarios where it is most advantageous. With both MOS and IFS capabilities, a DMD-based instrument is a versatile asset fit for a variety of astronomy missions

    DEVELOPMENT OF A SIMPLIFIED, MASS PRODUCIBLE HYBRIDIZED AMBIENT, LOW FREQUENCY, LOW INTENSITY VIBRATION ENERGY SCAVENGER (HALF-LIVES)

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    Scavenging energy from environmental sources is an active area of research to enable remote sensing and microsystems applications. Furthermore, as energy demands soar, there is a significant need to explore new sources and curb waste. Vibration energy scavenging is one environmental source for remote applications and a candidate for recouping energy wasted by mechanical sources that can be harnessed to monitor and optimize operation of critical infrastructure (e.g. Smart Grid). Current vibration scavengers are limited by volume and ancillary requirements for operation such as control circuitry overhead and battery sources. This dissertation, for the first time, reports a mass producible hybrid energy scavenger system that employs both piezoelectric and electrostatic transduction on a common MEMS device. The piezoelectric component provides an inherent feedback signal and pre-charge source that enables electrostatic scavenging operation while the electrostatic device provides the proof mass that enables low frequency operation. The piezoelectric beam forms the spring of the resonant mass-spring transducer for converting vibration excitation into an AC electrical output. A serially poled, composite shim, piezoelectric bimorph produces the highest output rectified voltage of over 3.3V and power output of 145uW using Âź g vibration acceleration at 120Hz. Considering solely the volume of the piezoelectric beam and tungsten proof mass, the volume is 0.054cm3, resulting in a power density of 2.68mW/cm3. Incorporation of a simple parallel plate structure that provides the proof mass for low frequency resonant operation in addition to cogeneration via electrostatic energy scavenging provides a 19.82 to 35.29 percent increase in voltage beyond the piezoelectric generated DC rails. This corresponds to approximately 2.1nW additional power from the electrostatic scavenger component and demonstrates the first instance of hybrid energy scavenging using both piezoelectric and synchronous electrostatic transduction. Furthermore, it provides a complete system architecture and development platform for additional enhancements that will enable in excess of 100uW additional power from the electrostatic scavenger

    MEMS Technology Demonstration on Traveler-I

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    Traveler-I is a flight test platform for advanced micro-electro-mechanical systems (MEMS) devices that is being built at the University of Southern California (USC) and is to be flown aboard the next ScorpiusÂŽ sub-orbital launch vehicle. Microcosm, Inc. and Scorpius Space Launch Company have initiated a program that currently provides sub-orbital launch opportunities, with the possibility of orbital flights in the future. Flight opportunities such as these allow for short duration missions where new technologies can be rapidly developed and tested in a launch and space environment. Traveler-I allows for low cost flight demonstration and testing of new and innovative MEMS devices such as a Free-Molecule Micro-Resistojet (FMMR) and a Knudsen Compressor. The FMMR is a MEMSbased propulsion system for low impulse bit delivery, which is designed to perform attitude control and primary maneuvers for nanosatellites. The Knudsen Compressor is a MEMS-based vacuum pump that employs the physical principle of thermal transpiration to drive a flow across an aerogel substance. Advances in MEMS capabilities have allowed the construction of micro-scale versions of space sensors such as mass spectrometers, optical spectrometers, and gas chromatographs. These devices require vacuum pumps to provide the necessary environment for their operation. Inexpensive and rapid access to space may eventually lead to low-cost testing, which supports rapid development and redesign so that more mature and reliable technologies can be used in future satellite systems, without the expense of designing, building and operating an entire satellite. In addition, the size of MEMS devices allows for the testing of multiple systems simultaneously. Traveler-I is a good example of how advanced technologies may be tested for low cost while reducing risk and development time for future programs

    Radiation Hardness Assurance: Evolving for NewSpace

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    During the past decade, numerous small satellites have been launched into space, with dramatically expanded dependence on advanced commercial-off-the-shelf (COTS) technologies and systems required for mission success. While the radiation effects vulnerabilities of small satellites are the same as those of their larger, traditional relatives, revised approaches are needed for risk management because of differences in technical requirements and programmatic resources. While moving to COTS components and systems may reduce direct costs and procurement lead times, it undermines many cost-reduction strategies used for conventional radiation hardness assurance (RHA). Limited resources are accompanied by a lack of radiation testing and analysis, which can pose significant risksor worse, be neglected altogether. Small satellites have benefited from short mission durations in low Earth orbits with respect to their radiation response, but as mission objectives grow and become reliant on advanced technologies operating for longer and in harsher environments, requirements need to reflect the changing scope without hindering developers that provide new capabilities

    Study for femto satellites using micro control moment gyroscope

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    Abstract— Femto-satellites can be used for distributed space missions that can require hundreds to thousands of satellites for real time, distributed, multi-point networks to accomplish remote sensing and science objectives. While suitable sensors are available using micro-electro-mechanical system technology, most femto-satellite designs have no attitude control capability due to the power and size constraints on attitude control actuators. A novel femto-satellite design that uses a micro-electro-mechanical system Control Moment Gyroscope is studied in this paper. We focus on the principal design, modelling, and discussion of the proposed Control Moment Gyroscope while detailing a controllable femto-satellite design that can make use of attitude control for simple sensing missions

    Small Magnetic Sensors for Space Applications

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    Small magnetic sensors are widely used integrated in vehicles, mobile phones, medical devices, etc for navigation, speed, position and angular sensing. These magnetic sensors are potential candidates for space sector applications in which mass, volume and power savings are important issues. This work covers the magnetic technologies available in the marketplace and the steps towards their implementation in space applications, the actual trend of miniaturization the front-end technologies, and the convergence of the mature and miniaturized magnetic sensor to the space sector through the small satellite concept

    Development of a sensor for microvibrations measurement in the AlbaSat CubeSat mission

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    openMicrovibrations on spacecraft represent an issue for payloads requiring high pointing accuracy and/or stability over time, and they might represent a particular concern for CubeSats and small satellites that, usually, are not equipped with very-high performance attitude control systems. Hence, collecting reliable measures of the vibration spectra during the operations of a CubeSat represents a significant research activity. This thesis presents the development of a sensor, configured as a payload within the AlbaSat mission, capable of accurately measuring the microvibrations in space, with particular focus on those produced by the Momentum Exchange Devices (MED), i.e., Reaction or Momentum Wheels, that represent one of the most important microvibrations sources. The thesis takes place in the framework of the AlbaSat mission. AlbaSat is a 2U CubeSat developed by a student team of the University of Padova under the “Fly Your Satellite! – Design Booster” programme promoted by the European Space Agency (ESA). The mission has four different objectives: (1) to collect measurements of the space debris environment in-situ, (2) to measure the microvibrations on board the CubeSat, (3) to precisely determine the position of the satellite through laser ranging and (4) to investigate alternative systems for possible Satellite Quantum Communication applications on nanosatellites. The requirements for the correct sizing of the sensor and the chosen physical and functional architecture are defined and presented in the thesis. A meticulous schedule for functional tests is finally outlined, aimed at verifying the correct functionality of the microvibration sensor. These tests serve as a starting point for the future development of the payload.Microvibrations on spacecraft represent an issue for payloads requiring high pointing accuracy and/or stability over time, and they might represent a particular concern for CubeSats and small satellites that, usually, are not equipped with very-high performance attitude control systems. Hence, collecting reliable measures of the vibration spectra during the operations of a CubeSat represents a significant research activity. This thesis presents the development of a sensor, configured as a payload within the AlbaSat mission, capable of accurately measuring the microvibrations in space, with particular focus on those produced by the Momentum Exchange Devices (MED), i.e., Reaction or Momentum Wheels, that represent one of the most important microvibrations sources. The thesis takes place in the framework of the AlbaSat mission. AlbaSat is a 2U CubeSat developed by a student team of the University of Padova under the “Fly Your Satellite! – Design Booster” programme promoted by the European Space Agency (ESA). The mission has four different objectives: (1) to collect measurements of the space debris environment in-situ, (2) to measure the microvibrations on board the CubeSat, (3) to precisely determine the position of the satellite through laser ranging and (4) to investigate alternative systems for possible Satellite Quantum Communication applications on nanosatellites. The requirements for the correct sizing of the sensor and the chosen physical and functional architecture are defined and presented in the thesis. A meticulous schedule for functional tests is finally outlined, aimed at verifying the correct functionality of the microvibration sensor. These tests serve as a starting point for the future development of the payload

    New Launch Methodologies for the Micro-Millennia

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    Rapid advancements in nano-technology have led to numerous improvements in microsatellite design. In the past twenty years, this class of satellites (10-100 kg mass) has repeatedly demonstrated their worth as vehicles for space science, technology demonstration, communications, remote sensing, education and information transfer. Within the past decade, the dramatic transition from experimentation to significant applications has prompted the implementation of numerous new launch methodologies. However, none have adequately met all the requirements stipulated by the small satellite market. The STARSAT launch vehicle has been tailored to specifically address the needs of the micro-satellite mission at a fraction of the cost of conventional launch systems. In addition, the predefined orbital parameters of these historically secondary payloads are no longer adequate for these mature and significant satellite missions. The implementation of the STARSAT design will enable low earth orbital insertion at any inclination without a corresponding increase in consumer cost. STARSAT will permit a wide array of scientific organizations, engineering corporations, universities, and even individuals, economically realistic access to space. The STARSAT launch system utilizes high altitude space balloons coupled with an optimized propulsion platform to initiate a high performance LEO (Low Earth Orbit) transfer maneuver from a stratospheric altitude of 20 to 25 kilometers. Lack of drag, near earth gravity, and high atmospheric pressures coupled with a heavy focus on reducing overall payload mass enables STARSAT to achieve high orbital altitudes with minimal propulsion requirements. Phase 1 of the STARSAT design, fabrication and launch underway at the Kennedy Space Center in Florida is led by the development teams of STARHUNTER Corporation in conjunction with the National Aeronautics and Space Administration, The Florida Space Institute and the Central Florida Remote Sensing Labs. This conceptual report details the STARSAT orbital insertion profile, as well as subsystem design with a focus on propulsion and guidance techniques. Telemetry from the maiden launch of STARSAT will be discussed, in addition to future design goals. Overall, STARSAT has resulted in a cost effective mission profile for use throughout the small satellite industry

    Design, Development, Test, and Evaluation of Atmosphere Revitalization and Environmental Monitoring Systems for Long Duration Missions

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    The Advanced Exploration Systems Program's Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project is working to mature optimum atmosphere revitalization and environmental monitoring system architectures. It is the project's objective to enable exploration beyond Lower Earth Orbit (LEO) and improve affordability by focusing on three primary goals: 1) achieving high reliability, 2) reducing dependence on a ground-based logistics resupply model, and 3) maximizing commonality between atmosphere revitalization subsystem components and those needed to support other exploration elements. The ARREM project's strengths include using existing developmental hardware and testing facilities, when possible, and and a well-coordinated effort among the NASA field centers that contributed to past ARS and EMS technology development projects

    MEMS deformable mirror CubeSat testbed

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    To meet the high contrast requirement of 1 × 10[superscript −10] to image an Earth-like planet around a Sun-like star, space telescopes equipped with coronagraphs require wavefront control systems. Deformable mirrors are a key element of these systems that correct for optical imperfections, thermal distortions, and diffraction that would otherwise corrupt the wavefront and ruin the contrast. However, high-actuator-count MEMS deformable mirrors have yet to fly in space long enough to characterize their on-orbit performance and reduce risk by developing and operating their supporting systems. The goal of the MEMS Deformable Mirror CubeSat Testbed is to develop a CubeSat-scale demonstration of MEMS deformable mirror and wavefront sensing technology. In this paper, we consider two approaches for a MEMS deformable mirror technology demonstration payload that will fit within the mass, power, and volume constraints of a CubeSat: 1) a Michelson interferometer and 2) a Shack-Hartmann wavefront sensor. We clarify the constraints on the payload based on the resources required for supporting CubeSat subsystems drawn from subsystems that we have developed for a different CubeSat flight project. We discuss results from payload lab prototypes and their utility in defining mission requirements.United States. National Aeronautics and Space Administration (Office of the Chief Technologist NASA Space Technology Research Fellowship)Jeptha and Emily Wade FundMassachusetts Institute of Technology. Undergraduate Research Opportunities Progra
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