Space Science Applications Research Articles

NELIOTA: Methods, statistics, and results for meteoroids impacting the Moon

Context. This paper contains results from the first 30 months of the NELIOTA project for near-Earth objects and meteoroids impacting the lunar surface. We present our analysis of the statistics concerning the efficiency of the campaign and the parameters of the projectiles and those of their impacts. Aims. The parameters of the lunar impact flashes are based on simultaneous observations in two wavelength bands. They are used to estimate the distributions of the masses, sizes, and frequency of the impactors. These statistics can have applications in both space engineering and science. Methods. The photometric fluxes of the flashes are measured using aperture photometry and their apparent magnitudes are calculated using standard stars. Assuming that the flashes follow a black body law of irradiation, the temperatures can be derived analytically, while the parameters of the projectiles are estimated using fair assumptions on their velocity and luminous efficiency of the impacts. Results. There have been 79 lunar impact flashes observed with the 1.2 m Kryoneri telescope in Greece. The masses of the meteoroids range between 0.7 g and 8 kg, and their respective sizes between 1 and 20 cm, depending on their assumed density, impact velocity, and luminous efficiency. We find a strong correlation between the observed magnitudes of the flashes and the masses of the meteoroids. Moreover, an empirical relation between the emitted energies of each band has been derived, allowing for an estimation of the physical parameters of the meteoroids that produce low energy impact flashes. Conclusions. The NELIOTA project has so far the highest detection rate and the faintest limiting magnitude for lunar impacts compared to other ongoing programs. Based on the impact frequency distribution on the Moon, we estimate that sporadic meteoroids with typical masses less than 100 g and sizes less than 5 cm enter the mesosphere of the Earth with a rate of ~108 meteoroids h−1 and also impact Moon with a rate of ~8 meteoroids h−1.

Brushed Crystallized Ultrathin Oxides: Recrystallization and Deep-Ultraviolet Imaging Application

Ultrawide band gap oxides have attracted attention for deep-ultraviolet (DUV) imaging detection which possesses a wide range of applications in space science, secure communication, and biological r...

Investigation of intrinsic aberrations introduced by the fringing field in the proposed 300 MeV proton microprobe in Harbin

In Harbin, the 300 MeV proton microprobe system with long-length quadrupole lenses, as a component of the Space Environment Simulation Research Infrastructure (SESRI), is under development driven by many applications in space science and proton therapy. Significant challenges have previously been addressed including minimization of ion scattering from collimators and the development of promising focusing systems compatible with the large beam magnetic rigidity. Here the intrinsic aberrations contributed by the fringe field regions of quadrupole lenses in the probe forming lens system are investigated with respect to the model used for the fringe field profile. The investigation compares the rectangular model, commonly used with the matrix method, and a more sophisticated model employing a multiphysics code for the full field profile used with a numerical raytracing method. For computational and constructional efficiency the proposed triplet system of long-length quadruple lenses required to achieve strong focusing was split into three pairs of two identical short quadrupole lenses, forming a sextuplet microprobe system. The comparison of the two fringe field models show large variations in the aberration coefficients of this system, however the rectangular model is suitable for a broad survey of possible systems to identify promising configurations for further optimization.

A high excitation magnetic quadrupole lens quadruplet incorporating a single octupole lens for a low spherical aberration probe forming lens system

Abstract This paper describes the design of a new probe forming lens system consisting of a high excitation magnetic quadrupole lens quadruplet that incorporates a single magnetic octupole lens. This system achieves both a high demagnification and a low spherical aberration compared to conventional high excitation systems and is intended for deployment for the Harbin 300 MeV proton microprobe for applications in space science and ion beam therapy. This relative simplicity of the ion optical design to include a single octupole lens minimizes the risks associated with the constructional and operational precision usually needed for the probe forming lens system and this system could also be deployed in microprobe systems that operate with less magnetically rigid ions. The design of the new system is validated with reference to two independent ion optical computer codes.

Geant4 Standard and Low Energy electromagnetic libraries

Geant4 is a Monte Carlo toolkit well established for large scale simulations for high energy physics, medicine, space science and other applications. Electromagnetic (EM) physics libraries are key components of these simulations. In this work we describe the Standard and Low Energy EM libraries available in Geant4 version 10.3 including descriptions of new models and interfaces relevant for dark matter searches and limits of applicability for these models.

GEANT4 models for the secondary radiation flux in the collimation system of a 300 MeV proton microbeam

In Harbin, we are developing a 300MeV proton microbeam for many applications in space science including upset studies in microelectronic devices, radiation hardness of materials for satellites and radiation effects in human tissues. There are also applications of this facility proposed for proton therapy. The microbeam system will employ a purpose-built proton synchrotron to provide the beam. However there are many challenges to be addressed in the design, construction and operation of this facility. Here we address two important design aspects for which we apply GEANT4 modeling. First, the high energy proton beam interacts strongly with beam line materials, especially the collimation slits, to produce showers of secondary particles which could introduce significant background signals and degrade the resolution of the proton microbeam. Second, the beam transport within the residual vacuum of the beam line may also introduce undesirable background radiation. In both cases mitigation strategies need to be incorporated during the design phase of the new system. We study the use of a dipole magnet following the aperture collimator to reduce the flux of secondary particles incident on the analysis chamber. Monte Carlo simulations are performed using GEANT4 and SRIM. By inserting the dipole magnet, we find as expected a significant reduction in the scattering of protons and other particles, such as neutrons and gamma rays, at the collimation system exit position. Secondary radiation from the residual gas pressure within the beam line vacuum system are also modelled and found to be negligible under the standard operating conditions.

A Hybrid CPU–GPU Real-Time Hyperspectral Unmixing Chain

Hyperspectral images are used in different applications in Earth and space science, and many of these applications exhibit real- or near real-time constraints. A problem when analyzing hyperspectral images is that their spatial resolution is generally not enough to separate different spectrally pure constituents (endmembers); as a result, several of them can be found in the same pixel. Spectral unmixing is an important technique for hyperspectral data exploitation, aimed at finding the spectral signatures of the endmembers and their associated abundance fractions. The development of techniques able to provide unmixing results in real-time is a long desired goal in the hyperspectral imaging community. In this paper, we describe a real-time hyperspectral unmixing chain based on three main steps: 1) estimation of the number of endmembers using the hyperspectral subspace identification with minimum error (HySime); 2) estimation of the spectral signatures of the endmembers using the vertex component analysis (VCA); and 3) unconstrained abundance estimation. We have developed new parallel implementations of the aforementioned algorithms and assembled them in a fully operative real-time unmixing chain using graphics processing units (GPUs), exploiting NVIDIA’s compute unified device architecture (CUDA) and its basic linear algebra subroutines (CuBLAS) library, as well as OpenMP and BLAS for multicore parallelization. As a result, our real-time chain exploits both CPU (multicore) and GPU paradigms in the optimization. Our experiments reveal that this hybrid GPU–CPU parallel implementation fully meets real-time constraints in hyperspectral imaging applications.

Novel 4He Circulator for Cooling of Large Space Superconducting Magnets

Large superconducting magnets are used in various space science applications (that is, particle detectors designed to search for antimatter, dark matter, and the origin of cosmic rays in space). To prevent or recover from a potential magnet quench, it is extremely important to control the operating temperature of superconducting magnets. One effective method for maintaining superconducting coils at sufficiently low temperatures while in application is to exchange heat with He-II, which exhibits an abnormally high, effective thermal conductivity () under certain conditions. In this work, a novel superfluid magnetic pump with no moving parts is discussed as a new method for maintaining magnet coils below their superconducting transition temperature . Unlike traditionally used thermomechanical pumps, the superfluid magnetic pump will have minimal superfluid helium depletion and will be able to provide flow rates that enable maintaining of the superconducting magnet coils at low temperatures.

ChemInform Abstract: Space Science Applications for Conducting Polymer Particles: Synthetic Mimics for Cosmic Dust and Micrometeorites

AbstractReview: 118 refs.

Performance evaluation of a prototype multi-bounce time-of-flight mass spectrometer in linear mode and applications in space science

Mass spectrometry is a powerful tool to measure the composition of volatile and semi volatile gases. The necessity to accurately identify and quantify unknown species lead to the requirements of a mass spectrometer as the detector of choice in most separation science and direct sample analysis situations. Advantages of time-of-flight mass spectrometry (TOFMS) are the high mass resolution, high mass range, and the measurement of the entire mass range in each extraction. The multi-bounce time-of-flight mass spectrometer (MBTOF) described in this work, takes advantage of a small footprint without sacrificing mass resolution. To achieve this, the MBTOF prototype uses a linear flight path with dual lens stacks. Ions are bounced in between the mirrors for a specified duration whereby increasing their flight time and resolution. The number of bounces can tune the resolution of the instrument. To show the minimum capabilities of the instrument and further applications of it, MBTOF was operated in linear mode. The instrument is designed for a multibounce passage of the ion optics and the focal point of the ion optics is optimized for this application, therefore the resolution in linear mode is limited. However, even in linear mode of operation, the mass resolution meets or exceeds that of a quadrupole mass spectrometer with limited power supplies required for operations. The measurements presented here are based on lab measurements of the early lab prototype MBTOF operated in a linear flight mode with low ion source extraction fields. A detailed evaluation including filament characterization, dynamic range and resolution are investigated. Further discussion involving applications on planetary missions for rocket science, coupling of MBTOF with laser thermal desorption or gas chromatography for potential organic determination in deep space are included.

Upscreening of LED COTS for space science applications

An upscreening flow has been defined and applied to COTS LED components. It was made possible by the transparent flat glass packaging of the LED, enabling direct visibility of the assembly up to the epitaxy interface through the transparent sapphire substrate.

Space science applications for conducting polymer particles: synthetic mimics for cosmic dust and micrometeorites.

Over the last decade or so, a range of polypyrrole-based particles have been designed and evaluated for space science applications. This electrically conductive polymer enables such particles to efficiently acquire surface charge, which in turn allows their acceleration up to the hypervelocity regime (>1 km s(-1)) using a Van de Graaff accelerator. Either organic latex (e.g. polystyrene or poly(methyl methacrylate)) or various inorganic materials (such as silica, olivine or pyrrhotite) can be coated with polypyrrole; these core-shell particles are useful mimics for understanding the hypervelocity impact ionisation behaviour of micro-meteorites (a.k.a. cosmic dust). Impacts on metal targets at relatively low hypervelocities (<10 km s(-1)) generate ionic plasma composed mainly of molecular fragments, whereas higher hypervelocities (>10 km s(-1)) generate predominately atomic species, since many more chemical bonds are cleaved if the particles impinge with higher kinetic energy. Such fundamental studies are relevant to the calibration of the cosmic dust analyser (CDA) onboard the Cassini spacecraft, which was designed to determine the chemical composition of Saturn's dust rings. Inspired by volcanism observed for one of the Jupiter's moons (Io), polypyrrole-coated sulfur-rich latexes have also been designed to help space scientists understand ionisation spectra originating from sulfur-rich dust particles. Finally, relatively large (20 μm diameter) polypyrrole-coated polystyrene latexes have proven to be useful for understanding the extent of thermal ablation of organic projectiles when fired at ultralow density aerogel targets at up to 6.1 km s(-1) using a Light Gas Gun. In this case, the sacrificial polypyrrole overlayer simply provides a sensitive spectroscopic signature (rather than a conductive overlayer), and the scientific findings have important implications for the detection of organic dust grains during the Stardust space mission.

Space magnetometer based on an anisotropic magnetoresistive hybrid sensor.

We report on the design and development of a low resource, dual sensor vector magnetometer for space science applications on very small spacecraft. It is based on a hybrid device combining an orthogonal triad of commercial anisotropic magnetoresistive (AMR) sensors with a totem pole H-Bridge drive on a ceramic substrate. The drive enables AMR operation in the more sensitive flipped mode and this is achieved without the need for current spike transmission down a sensor harness. The magnetometer has sensitivity of better than 3 nT in a 0-10 Hz band and a total mass of 104 g. Three instruments have been launched as part of the TRIO-CINEMA space weather mission, inter-calibration against the International Geomagnetic Reference Field model makes it possible to extract physical signals such as field-aligned current deflections of 20-60 nT within an approximately 45,000 nT ambient field.

Implementation of LOCO-I Lossless Image Compression Algorithm for Deep Space Applications

&lt;p&gt;Present emerging trend in space science applications is to explore and utilize the deep space. Image coding in deep space communications play vital role in deep space missions. Lossless image compression has been recommended for space science exploration missions to retain the quality of image. On-board memory and bandwidth requirement is reduced by image compression. Programmable logic like field programmable gate array (FPGA) offers an attractive solution for performance and flexibility required by real time image compression algorithms. The powerful feature of FPGA is parallel processing which allows the data to process quicker than microprocessor implementation. This paper elaborates on implementing low complexity lossless image compression algorithm coder on FPGA with minimum utilization of onboard resources for deep space applications.&lt;/p&gt;

Implementation of LOCO-I Lossless Image Compression Algorithm for Deep Space Applications

&lt;p&gt;Present emerging trend in space science applications is to explore and utilize the deep space. Image coding in deep space communications play vital role in deep space missions. Lossless image compression has been recommended for space science exploration missions to retain the quality of image. On-board memory and bandwidth requirement is reduced by image compression. Programmable logic like field programmable gate array (FPGA) offers an attractive solution for performance and flexibility required by real time image compression algorithms. The powerful feature of FPGA is parallel processing which allows the data to process quicker than microprocessor implementation. This paper elaborates on implementing low complexity lossless image compression algorithm coder on FPGA with minimum utilization of onboard resources for deep space applications.&lt;/p&gt;

Low Temperature Direct-Write Fabrication of Radio Frequency Identification Circuit and Antenna Structures on Polymer Substrates

We report the direct-write fabrication of electric circuits on polyethylene terephthalate (PET) substrates by a low temperature technique. To demonstrate the utility of the concept, Radio Frequency Identification Circuit and Antenna Structures were fabricated on polyethylene terephthalate (PET), using a 300 dpi drop-on-demand HP DeskJet system. First, each substrate was prepared by low frequency atmospheric plasma etching, followed by tin (II) chloride treatment to enhance wetting. Then a catalytic silver seed layer pattern was bubble-jet printed onto the surface. Finally, the substrate was developed in a copper electroless plating bath for 10 min. to yield a 2.5 µm copper film with a sheet resistance of 3.4 Ωsq. The as-deposited film was shiny with a surface roughness of less than 8.7nm, which is about 0.35% of the film thickness. The films were characterized by SEM, EDX, profilometry, optical microscopy, and four-point probe resistivity measurement. This technology may be adapted for the direct-write fabrication of antenna structures for communication devices and space science applications.

Silicon Drift Detectors for Readout of Scintillators in Gamma-Ray Spectroscopy

In this work, we report on a new development of Silicon Drift Detectors (SDDs) for gamma-ray spectroscopy with space science applications. The research is supported by the European Space Agency through the Technology Research Programme (TRP). The final goal of the development is the realization of monolithic arrays of SDDs which will be assembled to readout large (2” and 3”) LaBr3(Ce) scintillators. We present here the results of the development of a single SDD prototype, with 8 × 8 mm2 active area, produced at Fondazione Bruno Kessler (FBK) semiconductor laboratories. We discuss the design issues related to the specific use of this device as a photo-detector for scintillators. Then, we focus on the read-out electronics. Since this SDD does not include a front-end transistor on the silicon chip, we have adopted a CMOS charge preamplifier (CUBE) recently developed at Politecnico di Milano. This preamplifier has allowed the achievement of state-of-the-art noise performance using a SDD technology process without the integration of the FET (Field Effect Transistor) on the detector chip. A quantum efficiency of about 80% has been measured for the SDD at the emission wavelength band of LaBr3 (360-380 nm). First experimental measurements consisting of direct 55 Fe irradiation of the SDD without scintillator, have demonstrated energy resolution of 140 eV and 129 eV at -20°C and -43°C respectively. By coupling the SDD with a LaBr3(Ce) scintillator (9 mm diameter), we have measured energy resolution of 5.6% FWHM and 2.6% FWHM at 122 keV and 662 keV respectively.

High-Sensitivity Raman Spectrometer To Study Pristine and Irradiated Interstellar Ice Analogs

We discuss the novel design of a sensitive, normal-Raman spectrometer interfaced to an ultra-high vacuum chamber (5 × 10(-11) Torr) utilized to investigate the interaction of ionizing radiation with low temperature ices relevant to the solar system and interstellar medium. The design is based on a pulsed Nd:YAG laser which takes advantage of gating techniques to isolate the scattered Raman signal from the competing fluorescence signal. The setup incorporates innovations to achieve maximum sensitivity without detectable heating of the sample. Thin films of carbon dioxide (CO2) ices of 10 to 396 nm thickness were prepared and characterized using both Fourier transform infrared (FT-IR) spectroscopy and HeNe interference techniques. The ν+ and ν- Fermi resonance bands of CO2 ices were observed by Raman spectroscopy at 1385 and 1278 cm(-1), respectively, and the band areas showed a linear dependence on ice thickness. Preliminary irradiation experiments are conducted on a 450 nm thick sample of CO2 ice using energetic electrons. Both carbon monoxide (CO) and the infrared inactive molecular oxygen (O2) products are readily detected from their characteristic Raman bands at 2145 and 1545 cm(-1), respectively. Detection limits of 4 ± 3 and 6 ± 4 monolayers of CO and O2 were derived, demonstrating the unique power to detect newly formed molecules in irradiated ices in situ. The setup is universally applicable to the detection of low-abundance species, since no Raman signal enhancement is required, demonstrating Raman spectroscopy as a reliable alternative, or complement, to FT-IR spectroscopy in space science applications.

Synthesis and Array Processor Realization of a 2-D IIR Beam Filter for Wireless Applications

A broadband digital beamforming algorithm is proposed for directional filtering of temporally-broadband bandpass space-time plane-waves at radio frequencies (RFs). The enhancement of desired waves, as well as rejection of undesired interfering plane-waves, is simulated. A systolic- and wavefront-array architecture is proposed for the real-time implementation of second-order spatially-bandpass (SBP) 2-D infinite impulse response (IIR) beam filters having potential applications in broadband beamforming of temporally down-converted RF signals. The higher speed of operation and potentially reduced power consumption of the asynchronous architecture of wavefront-array processors (WAPs) in comparison to the conventional synchronous hardware has emerging applications in radio-astronomy, radar, navigation, space science, cognitive radio, and wireless communications. Further, the bit error rate (BER) performance improvement along with the reduced computational complexity of the 2-D IIR SBP frequency-planar digital filter over digital phased array feed (PAF) beamformer is provided. A nominal BER versus signal-to-interference ratio (SIR) gain of 10-16 dB compared to case where beamforming is not applied, and a gain of 2-3 dB at approximately half the number of parallel multipliers to digital PAF, are observed. The results of application-specific integrated circuit (ASIC) synthesis of the digital filter designs are also presented.

Cryogenics and its Application with Reference to Spice Grinding: A Review

Cryogenics is the study of very low temperature and its application on different materials including biological products. Cryogenics has numerous applications in space science, electronics, automobiles, the manufacturing industry, sports and musical instruments, biological science and agriculture, etc. Cryogenic freezing finds pivotal application in food, that is, spices and condiments. Although there is a wide range of cryogens to produce the desired low temperature, generally liquid nitrogen (LN2) is used in food grinding. The application of low temperature shows a promising pathway to produce higher quality end product with higher flavor and volatile oil retention. Cryogenic grinders generally consist of precoolers and grinder with the cryogen distribution system. In such grinding systems, cryogens subject the raw material up to or lower than glass transition temperature before it is ground, thus eliminating much of the material and quality hassles of traditional grinding. At present, the capital investment including cryogen and handling costs escalate the final cost of the product. Thus, for large-scale production, a proper design to optimize and make it feasible is the need of the hour and understanding the behavior of different food materials at these low temperature conditions. This article reviews the scenario and application of cryogenics in different sectors, especially to spice grinding.