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Possible applications of new CUDA-enabled systems-on-chip (SoCs) Tegra K1 and Tegra X1 in high-energy astrophysics are discussed in this paper. Hardware and software aspects of general purpose computing on graphics processing units (GPGPU) are briefly reviewed. An influence of space radiation effects on processors and a mitigation of its consequences are discussed.

Studies of three versions of electron guns (0.3 kV, 0.14 A; 20 kV, 0.1 A; 40 kV, 0.05 A) intended to operate aboard spacecraft during various space experiments are presented. The computer simulation results of electron-optical systems are given, the optimization of cathode-heating units and heat removal system are performed, circuit design of the gun power supplies for both the stationary mode and using a special modulator are discussed.

Moessbauer spectroscopy is a powerful tool for the mineralogical analysis of Fe-bearing materials. The miniaturized Moessbauer spectrometer MIMOS II has already been working on the surface of Mars for 6 years as part of the NASA Mars Exploration Rovers mission. The improved version of the instrument is a component of the scientific payload of the Phobos-Grunt mission. The scientific objectives of the instrument are the following: to identify the iron-bearing phases, to determine the quantitative distribution of iron among these phases, and to determine the distribution of iron among its oxidation states.

We consider a new design of a high-precision three-axial sensor of angular velocities whose sensitive elements are fiber optic gyroscopes using the Sagnac effect. The instrument is designed for measuring the rotation velocity of an orbiting spacecraft (microsatellite) and for performing its attitude control.

Results of computational and theoretical studies are presented. A formulation of the problem is given and approaches to its solution are described. Brief information is given on the models, difference methods, and software designed or adapted to perform direct numerical modeling of mass‐spectrometric measurements of cometary dust on PUMA instruments. The results of a number of computational experiments are presented.

A quartz sensor of small accelerations with a capacitive transducer is designed and produced, allowing one to measure spacecraft accelerations with a resolution of 10–7 m/s2 in the range ±10–1 m/s2. The results of calibration of the sensor by the method of inclinations are presented.

A gas-discharge anemometer is designed for investigating the gas-flow dynamics in wind tunnels, and in experimental and space meteorology. The anemometer allows one to measure simultaneously the magnitude and direction of the gas-flow velocity vector and the gas pressure in the flow. The instrument consists of a gas-discharge chamber, an analyzer of scattered ions, a power supply unit, and a measuring unit. The anemometer weight does not exceed 0.1 kg, and the power consumption does not exceed 0.2 W. The instrument was put through preliminary tests in a wind tunnel that simulated, in particular, the conditions in the boundary layer of the Martian atmosphere and produced a directed gas (air or CO2) flow whose velocity could be varied from 0.5 to 50 m/s at pressures from 0.3 to 1.3 kPa and temperatures from –120 to +20°C. The anemometer sensitivity is no worse than 100 mV/(m/s). The method of calculating the gas-flow velocity on the basis of the measured ion-current distributions is developed.

An analysis of the spectra from the PUMA dust-impact mass spectrometers onboard the Vega-1 and Vega-2 spacecraft shows that a large number of the observed, unidentified small-amplitude peaks are produced by impacts of very-low-mass (from 10−17 to 10−20 g) particles. The mass flux of very fine particles accounts for a few percent of the total dust mass flux from comet Halley. The elemental composition of the finest cometary particles is identical to the composition of large particles (10−12–10−16 g), in agreement with present views about the nucleus of comet Halley as an aggregate of interstellar dust.

The general scientific objectives of an in situ experiment employing a Mossbauer spectrometer on a Martian lander are, for both rock and soil samples, identification and relative abundance of iron-bearing minerals (including carbonates, phyllosilicates (clays), hydroxyoxides, phosphates, oxides, silicates, sulfides, sulfates), measurement of the ferric (Fe3−) to ferrous (Fe2+) ratio, determination of the properties of magnetic phases including the size distribution of magnetic particles (nanophase versus larger particles) in the Martian soil. These data provide information about the nature and extent of atmosphere-surface chemical and physical weathering processes involving Fe-bearing phases. These objectives are directly relevant to studying the evolution of volatiles and climate over time on Mars because surface materials are major volatile sinks. In fact one of the major problems associated with understanding the evolution of volatiles on Mars is understanding the processes in the past and/or present that are responsible for oxidizing the red planet. A miniaturized backscattering Mossbauer spectrometer, developed at the Technical University of Darmstadt, is reported on which is a flight prototype of an instrument that could be used for in situ analysis as part of a payload of a Martian lander. Its critical instrument parameters are

A Mossbauer spectrometer is included in the preliminary payload of a rover to be placed on the surface of Mars in the Soviet mission to the planct in 1996/1,2/. In counection with the American planctary program it has also been suggested to construct a Mossbauer spectrometer to be landed on Mars /3, 4/. The objective is to study the iron compounds of the Martian soil and rocks by backscattering Mossbauer spectroscopy. The paper describes the significance of the element iron in the study of the evolution of the planetary system and what we might expect to learn from Mossbauer spectroscopy of the surface materials of Mars. The study of Mars is expected to expand substantially in the coming decades, probably culminating with a manned flight to the planet. The international Mossbauer community may contribute significantly to the preparation of these events.

The fact that the small bodies as Comets and asteroids have been submitted to a very weak evolution turn them into witness materials of the early stages of formation of the solar system. After the successful multi—spacecraft missions to the Halley comet a great interest is focusing now on asteroids. The soviet mission to Phobos, launched in July 1988 is a peculiar opportunity to study such a small body which could reasonably be a capturated asteroid. The peculiarity is also in the very low and very slow flyby that can be performed in the case of Phobos ; it has been taken advantage of that to use methfds of active remote chemical analysis derived from the laboratory techniques SIMS and LAMMA

Additonal co-authors: P Gutlich, E Kankeleit, T McCoy, DW Mittlefehldt, F Renz, ME Schmidt, B Zubkov, SW Squyres, RE Arvidson

The Moessbauer spectrometer on Spirit measured the oxidation state of Fe, identified Fe-bearing phases, and measured relative abundances of Fe among those phases for surface materials on the plains and in the Columbia Hills of Gusev crater. Eight Fe-bearing phases were identified: olivine, pyroxene, ilmenite, magnetite, nanophase ferric oxide (npOx), hematite, goethite, and a Fe(3+)-sulfate. Adirondack basaltic rocks on the plains are nearly unaltered (Fe(3+)/Fe(sub T) Px), and minor npOx and magnetite. Columbia Hills basaltic rocks are nearly unaltered (Peace and Backstay), moderately altered (WoolyPatch, Wishstone, and Keystone), and pervasively altered (e.g., Clovis, Uchben, Watchtower, Keel, and Paros with Fe(3+)/Fe(sub T) approx.0.6-0.9). Fe from pyroxene is greater than Fe from olivine (Ol sometimes absent), and Fe(2+) from Ol+Px is 40-49% and 9-24% for moderately and pervasively altered materials, respectively. Ilmenite (Fe from Ilm approx.3-6%) is present in Backstay, Wishstone, Keystone, and related rocks along with magnetite (Fe from Mt approx. 10-15%). Remaining Fe is present as npOx, hematite, and goethite in variable proportions. Clovis has the highest goethite content (Fe from Gt=40%). Goethite (alpha-FeOOH) is mineralogical evidence for aqueous processes because it has structural hydroxide and is formed under aqueous conditions. Relatively unaltered basaltic soils (Fe(3+)/Fe(sub T) approx. 0.3) occur throughout Gusev crater (approx. 60-80% Fe from Ol+Px, approx. 10-30% from npOx, and approx. 10% from Mt). PasoRobles soil in the Columbia Hills has a unique occurrence of high concentrations of Fe(3+)-sulfate (approx. 65% of Fe). Magnetite is identified as a strongly magnetic phase in Martian soil and dust.

Mössbauer spectra measured by the Opportunity rover revealed four mineralogical components in Meridiani Planum at Eagle crater: jarosite- and hematite-rich outcrop, hematite-rich soil, olivine-bearing basaltic soil, and a pyroxene-bearing basaltic rock (Bounce rock). Spherules, interpreted to be concretions, are hematite-rich and dispersed throughout the outcrop. Hematitic soils both within and outside Eagle crater are dominated by spherules and their fragments. Olivine-bearing basaltic soil is present throughout the region. Bounce rock is probably an impact erratic. Because jarosite is a hydroxide sulfate mineral, its presence at Meridiani Planum is mineralogical evidence for aqueous processes on Mars, probably under acid-sulfate conditions.

[1] Mossbauer spectroscopy is a powerful tool for quantitative mineralogical analysis of Fe-bearing materials. The miniature Mossbauer spectrometer MIMOS II is a component of the Athena science payload launched to Mars in 2003 on both Mars Exploration Rover missions. The instrument has two major components: (1) a rover-based electronics board that contains power supplies, a dedicated central processing unit, memory, and associated support electronics and (2) a sensor head that is mounted at the end of the instrument deployment device (IDD) for placement of the instrument in physical contact with soil and rock. The velocity transducer operates at a nominal frequency of ∼25 Hz and is equipped with two 57Co/Rh Mossbauer sources. The reference source (∼5 mCi landed intensity), reference target (α-Fe2O3 plus α-Fe0), and PIN-diode detector are configured in transmission geometry and are internal to the instrument and used for its calibration. The analysis Mossbauer source (∼150 mCi landed intensity) irradiates Martian surface materials with a beam diameter of ∼1.4 cm. The backscatter radiation is measured by four PIN-diode detectors. Physical contact with surface materials is sensed with a switch-activated contact plate. The contact plate and reference target are instrumented with temperature sensors. Assuming ∼18% Fe for Martian surface materials, experiment time is 6–12 hours during the night for quality spectra (i.e., good counting statistics); 1–2 hours is sufficient to identify and quantify the most abundant Fe-bearing phases. Data stored internal to the instrument for selectable return to Earth include Mossbauer and pulse-height analysis spectra (512 and 256 channels, respectively) for each of the five detectors in up to 13 temperature intervals (65 Mossbauer spectra), engineering data for the velocity transducer, and temperature measurements. The total data volume is ∼150 kB. The mass and power consumption are ∼500 g (∼400 g for the sensor head) and ∼2 W, respectively. The scientific measurement objectives of the Mossbauer investigation are to obtain for rock, soil, and dust (1) the mineralogical identification of iron-bearing phases (e.g., oxides, silicates, sulfides, sulfates, and carbonates), (2) the quantitative measurement of the distribution of iron among these iron-bearing phases (e.g., the relative proportions of iron in olivine, pyroxenes, ilmenite, and magnetite in a basalt), (3) the quantitative measurement of the distribution of iron among its oxidation states (e.g., Fe2+, Fe3+, and Fe6+), and (4) the characterization of the size distribution of magnetic particles. Special geologic targets of the Mossbauer investigation are dust collected by the Athena magnets and interior rock and soil surfaces exposed by the Athena Rock Abrasion Tool and by trenching with rover wheels.

The survey of elemental composition of P/Halley dust component according to the data acquired by the PUMA-2 instrument installed on the board of the VEGA-2 spacecraft is presented. Possible mineralogical composition of dust particles is considered. Some reasons for possible presence in comet’s dust particles of virgin organic compounds are presented.

Time-of-flight dust-impact mass-analysers PUMA-1,2 aboard VEGA spacecrafts were intended to investigate the properties of Halley comet dust component by means of direct measurements in the nucleus vicinity. More then 2000 mass-spectra were obtained by PUMA-1 and more then 500 ones were obtained by PUMA-2. Masses of studied particles are in the range 5 10-17 – 10-12 g. The spectra measured in time analyzer mode (zero mode) were the most convinient for data treatment; the number of these spectra was about 4–5% from the total number of PUMA spectra. The principal elements (H, C, N, O, Na, Mg, Al, Si, S, CI, Ca and Fe) and their most abundant isotopes were found. The isotopic composition of C, Mg, Si, S, CI and Fe is similar to mean cosmic isotopic abundance.The cometary dust particles contain a significant amount of light elements (H, C, N and 0). Their presence can be easily explained by the presence of organic compounds similar to observed in carbonaceous chondrites. The results of cometary dust composition measurements shows to a possible similarity of interstellar and cometary dust and can be explained by a model of cometary nuclei as aggregates of interstellar dust particles with no substancial chemical evolution.

THE bulk chemical composition of the dust grains in the coma of comet Halley has been determined1–11 by examination of data from the PUMA 1 and 2 and PIA mass spectrometers on the Vega and Giotto missions. Although the bulk elemental composition of rock-forming elements (that is, excluding C, H, N and O) seemed to be close to solar (that is, similar to CI carbonaceous chondrites), the ion ratios of some of these elements, such as Mg+/Si+ and Fe+/Si+, are rather different from those in CI chondrites. There has not been, however, a satisfactory investigation of the chemical composition of individual grains as a function of their mass. Here we re-evaluate the PUMA 1 and 2 data to perform such an analysis. We find that the compositions of heavy and light grains are very different, with light grains being magnesium-rich (silicon-deficient), whereas the mean Mg+/Si+ ratio in heavy grains is similar to CI chondritic. The marked difference in composition between light and heavy grains indicates that the origin of the two grain populations might be different.

Dust-impact PUMA mass-analysers aboard the spacecrafts VEGA-1 and VEGA-2 allow to conduct the first direct measurements of mass spectra of comet Halley’s dust envelope particles with masses higher than 10 -17 g [1,2]. The analysis of spectra measured by the PUMA instruments showed that unindentified peaks in this spectra could be associated with very small particles (mass 10-17–10-20 g).

The conditions are formulated which must be satisfied by the vacuum system of a magnetic mirror trap when a dense plasma is built up using the fast ion injection method. In the previous experiments on OGRA-I and in experiments on the V-3 machine in which 40 keV H2+ ions are injected and dissociated by the residual gas and by the lithium arc and in experiments using targets, it has been established that bombardment of the titanium-covered cold adsorbing surfaces by fast atoms or ions produces an intense desorption. Taking these results into account it is proposed that all surfaces in the vacuum chamber of OGRA I which are subjected to bombardment by fast particles should be kept hot during build-up of the plasma, and that adsorption on cold titanium should only be employed in those parts which are inaccessible to fast particle bombardment. It is shown that in order to obtain a dense plasma it is expedient to discontinue using the external injector and to locate the ion source in one of the magnetic mirrors. It is discussed how the development of cyclotron instability may facilitate the capture of ions in the trap and the build-up of a dense plasma. It is noted that in OGRA I the adiabatic containment time for protons in the trap exceeds 200 msec, and for a density of hot plasma up to 1 × 108 cm-3, if losses ascribable to instabilities are present, the proton lifetime in the trap determined by these losses is greater than 70 msec.

Measurements of the element composition of the dust particles in Comet Halley were made by the PUMA-1 and PUMA-2 instruments onboard the VEGA spacecraft. The timeof-flight analysis of ions produced by the hypervelocity particle impact on the target was applied with a wide (W = 100 eV) and a narrow (W = 20 eV) energy window of the instruments. The analysis of measured spectra shows that the mass resolution for “small” particles (Q < 10−13 C) was high enough in both modes to separate individual mass lines. For large particles the resolution did not change for the narrow window, it decreased, however, for the wide one (to about 50). A relative transmission Q W /Q n dependence on the mass number for the wide and narrow window made has been found.

Mass spectra of cometary dust particles measured by the PIA dust particle analyzer aboard the Giotto spacecraft show some unexpected and striking features. First, small particles below 10 to the -14th g are much more abundant than anticipated by models. Second, most of the particles are rich in light elements such as H, C, N, and O, suggesting the validity of models that describe the cometary dust as including organic material. Third, the light elements specifically seem to have a low ratio of mass to volume. Three examples of original mass spectra showing typical compositions are given; these have been measured, and are compared with a computer-simulated mass spectrum.