Detection of suprathermal ionospheric O+ ions inside the plasmasphere

The plasma diagnostic experiments on the AUREOL-3 satellite have revealed flows of low energy 0⁺ ions deep inside the night plasmasphere during a large substorm. Flux gradients of the 0⁺ ions were accompanied by enhancements of ELF electric field noise. The appearance of suprathermal ions at $\text{L ? 2.5 – 3}$ is interpreted within the framework of electrostatic ion-cyclotron acceleration of ionospheric ions in the diffuse auroral zone /12/ followed by a radial displacement of these ions inside the plasmasphere driven by azimuthal electric fields during substorm activity. Electrostatic oscillations observed inside the plasmasphere are apparently associated with gradient instability at the sharp boundaries of suprathermal ion flows.     

Mesospheric ozone densities deduced from solar occultation measurements

Quartz-UV occultation measurements by the satellite Interkosmos-16 have been used to calculate ozone densities at altitudes between 50 and 90 km for the period August to October 1976. Below 65 km densities agree well with the Krueger-Minzner-model. Mesopause densities have been studied in some detail. A certain percentage of the profiles show close correlation with the model of Shimazaki and Laird (with a pronounced minimum below the mesopause) while others fit better to the Park and London model (no minimum). This variability of the ozone density may be caused by different processes in the photo-chemistry of ozone. Two possible causes, the temperature dependent rate coefficients and the odd hydrogen processes are discussed in greater detail.     

Processing of nutritious, safe and acceptable foods from CELSS candidate crops.

A controlled ecological life-support system (CELSS) is required to sustain life for long-duration space missions. The challenge is preparing a wide variety of tasty, familiar, and nutritious foods from CELSS candidate crops under space environmental conditions. Conventional food processing technologies will have to be modified to adapt to the space environment. Extrusion is one of the processes being examined as a means of converting raw plant biomass into familiar foods. A nutrition-improved pasta has been developed using cowpea as a replacement for a portion of the durum semolina. A freeze-drying system that simulates the space conditions has also been developed. Other technologies that would fulfill the requirements of a CELSS will also be addressed.     

Macrosegregation during crystal growth in horizontal bridgman boat

This paper is devoted to direct numerical simulation of the fluid flow and macrosegregation in horizontal Bridgman systems. Results concerning the fluid flows at Pr=0 and Pr=0.015 are given for various values of Gr and in situation where the melt-crystal interface is at rest. Practical laws concerning the behaviour of the mass transport and the level of inhomogeneity in the cavity are derived. The effects of some parameters such as Gr, Sc and the pulling speed on the concentration repartition in the two phases melt and crystal are studied and the average concentration in the crystal is shown for various situations.     

Galileo probe battery system

NASA's pair of Galileo spacecraft arrived at Jupiter on 7 December 1995. The Probe descended into the upper Jovian atmosphere, performing its planned sequence of scientific measurements of the properties of that medium for about an hour. This Probe has been the most ambitious planetary entry vehicle to date. It evolved over several years of planning and construction, its launch was postponed many times, for a variety of reasons; and it required more than 6 years of travel after launch to reach the planet. Its electrical power was provided by a primary Li-SO₂ battery, supplemented with two thermal batteries (CaCrO₄-Ca) used for firing pyrotechnic initiators during the atmospheric entry. These power sources were designed to be robust, to assure they would perform their intended function after surviving several years in space. This paper discusses the final production, qualification, and the systems testing of these batteries prior to and following launch. Their excellent performance at Jupiter confirmed their life enhancement design features     

Structure of cress root statocytes in microgravity (Bion-10 mission).

Experiments on primary roots of Lepidium sativum L. have been performed on board the Bion-10 satellite. The experimental set-up was extremely miniaturized and completely automatic. The results demonstrate the effectiveness of the instrumentation. The spatial orientation, growth, root cap differentiation and statocyte structure of roots grown under microgravity (MG) have been compared with control roots grown on the ground (GC) and in a 1G-reference centrifuge in space (RC). Root length and cap shape did not differ between MG and control samples. Under MG, the mean distance of the statoliths from the distal cell wall of the statocytes increased significantly, the mean distance of the mitochondria decreased and the nucleus did not change its position in comparison to both controls. The number and the shape of the amyloplasts (statoliths) were not influenced by the space flight factors, but their size as well as their relative area in the cell decreased. The number of starch grains per statolith as well as their size and shape changed under MG. In MG and RC samples the number of lipid bodies in the statocytes was higher and the relative area larger than in GC samples. The relative area occupied by vacuoles was greater in RC statocytes than in GC and MG statocytes. These results partly confirm and, in addition, extend the data from earlier experiments in space.     

An optimized GPS carrier phase ambiguity search method focusing onspeed and reliability

An optimized ambiguity search method is described in this paper focusing on speed and reliability. The method has incorporated several existing fast ambiguity search concepts and the ambiguity search speed can be further improved. In addition to the improvement of the ambiguity search speed, special attention has been paid to the improvement of the reliability of the ambiguity search process. Several theoretical and practical aspects involved in an ambiguity search algorithm are also addressed which have not been explored in previous literatures     

Photometric calibration and first results obtained with the UFT experiment on board the astron satellite

The UV telescope of 30 cm diameter equipped with a three channel scanner spectrometer aboard the highly eccentric orbit space station “ASTRON” is describedAbsolute calibration of the whole device is performed using spectra of standard stars, of which absolute values were obtained by TDI or IUE experiments. Several photometric controls have been made on the stability of the equipment after one year of operation which demonstrate reliability of some first results obtained by the UFT.The sensitivity curve of the spectrophotometric system has been observed with a reproducibility of 2σ = 10% or better.The repeated observation of one star (139 Tau) indicates that the overall performance exhibits the same quality after one year in orbit. The low resolution mode ($\text{Δ λ = 28}\text{A}\text{?}$) leads to a powerful new investigation of faint extended sources.     

1E 1740.7-2942 revisited: Confirmation of its identification with the core of a double sided radio jet structure

After more than two years of successful in-orbit operations, the γ-ray coded aperture SIGMA telescope has accumulated 800 hours of live-time observations of the Galactic Center region, including the remarkable hard source identified with the X-ray source 1E 1740.7–2942. The long-term behavior of the soft γ-ray emission of 1E 1740.7–2942, as determined from the SIGMA survey, supplemented with previously available soft γ-ray data, leads to its identification with a singular radio source, which consists of a double sided radio jet emanating from a compact variable core whose variability is correlated with that of the soft γ-ray source. The compact radio core, which lies well inside the improved soft γ-ray (40–150 keV) error circle (27″ radius) derived from the high-resolution SIGMA survey, is also inside the ROSAT and TTM error circle derived respectively in the soft and hard X-ray bands.