The role of calcium ions in cytological effects of hypogravity

Electron-cytochemical and biochemical methods made it possible to reveal certain differences in ATPase activity stimulation by calcium ions in root apex cells of pea seedlings and moss protonema $\text{Funaria}$$\text{hygrometrica}$ grown under stationary and slow clinostatic (2 rev/min) conditions. It was showed that under clinostatic conditions in comparison with the control variant the ATPase activity decreases in plasmalemma. The protein content in the plasmalemma fraction was also twice as low under these conditions. The root apex cells of the pea seedlings grown under spaceflight conditions were found to contain high concentrations of membrane-bound calcium. The data obtained are discussed in relation to problems of possible mechanisms of disturbance in calcium balance and the system of active calcium ion transport through plasmalemma under hypogravity.     

Temperature measurements during the CAMP program

The Cold Arctic Mesopause Program (CAMP) was conducted at ESRANGE, Sweden, in July/August 1982. During the time period of several weeks, the temperature was monitored by ground-based OH emission spectrometers and by stellite radiance measurements. Rocket launchings occurred on the nights of $\text{3}\text{4}$ and $\text{11}\text{12}$ August. On $\text{3}\text{4}$ August, seven rocket payloads were launched during a period of noctilucent cloud sighting over ESRANGE. The presence of the NLC was confirmed by several rocket-borne photometer profiles. The temperature measurements showed that the temperature profiles in the stratosphere and lower mesosphere were near the expected values of high latitude summer models. A large amplitude wave structure with three temperature minima of 139K, 114K and 111K were observed at altitudes between 83 and 94 km. The temperature minimum at 83 km was the location of the observed NLC. The temperature minima caused by the growth of the gravity wave amplitude in the highly stable mesosphere provide the regions for the growth of particles by nucleation to optical scattering size, as well as regions where the nuclei for condensation can be formed through ion chemistry paths.     

Long clinostation influence on the localization of free and weakly bound calcium in cell walls of Funaria hygrometrica moss protonema cells.

The pyroantimonate method was used to study the localization of free and weakly bound calcium in cells of moss protonema of Funaria hygrometrica Hedw. cultivated on a clinostat (2rev/min). Electroncytochemical study of control cells cultivated at 1 g revealed that granular precipitate marked chloroplasts, mitochondria, Golgi apparatus, lipid drops, nucleoplasma, nucleolus, nucleus membranes, cell walls and endoplasmic reticulum. In mitochondria the precipitate was revealed in stroma, in chloroplast it was found on thylakoids and envelope membranes. The cultivation of protonema on clinostat led to the intensification in cytochemical reaction product deposit. A considerable intensification of the reaction was noted in endomembranes, vacuoles, periplasmic space and cell walls. At the same time analysis of pectinase localization was made using the electroncytochemical method. A high reaction intensity in walls in comparison to that in control was found out to be a distinctive peculiarity of the cells cultivated on clinostat. It testifies to the fact that increasing of free calcium concentrations under conditions of clinostation is connected with pectinic substances hydrolysis and breaking of methoxy groups of pectins. Data obtained are discussed in relation to problems of possible mechanisms of disturbance in calcium balance of plant cells and the role of cell walls in gomeostasis of cell grown under conditions of simulated weightlessness.     

The role of cellulases in the mechanism of changes of cell walls of Funaria hygrometrica moss protonema at clinostating.

Using electroncytochemical and biochemical methods, differences between the cytochemical reaction intensity and activity of the cellulosolytic enzymes in Funaria hygrometrica moss cells grown for 30 days in the horizontal clinostat (2 rev/min) and in control have been studied. It has been shown that on clinostating the precipitate amount and size increases with the cellulase activity enhancement in the periplasmic space and protonema cell walls, when compared to control. Using biochemical methods it has been found that the activity of both endo-1,4-beta-glucanase and exo-1,4-beta-glucanase was higher under these conditions. A decrease of cellulose total content, its crystalline form, and pectic substances as well as an increase of hemicellulose content have been revealed in the clinostated material compared to control. Data obtained are discussed regarding the possible mechanism of cellulase activation and synthesis inhibition and cellulose crystallization in plant cell walls at clinostating.     

Long clinostation influence on the ultrastructure of Funaria hygrometrica moss protonema cells

Changes in the ultrastructure of protonema cells of Funaria hygrometrica, cultivated during 20 days on a horizontal clinostat (2 rev/min), were determined by the electron microscopy method. About 20% of the cells were almost identical to those in the control, 20% were destructive cells, and in 60% ultrastructure changes were observed. The heterogeneity of the reaction demonstrated the evidence of sensitive cells on the clinostation process. Changes affected the ultrastructure of plastids, wall of the cell, and the form of the nucleus as well. Starch disappeared from chloroplasts practically completely, thylakoids swelled, granas frequently disappeared from plastids. Peroxisomes number in cells increased appreciably, width of cell walls decreased by almost half their size. Ca⁺⁺-binding sites were revealed in cytoplasma of cells. Electronocytochemical exposure of ATPases activity with the presence of Mg⁺⁺ and Ca⁺⁺ ions showed that Mg²⁺-ATPase activity localization in clinosted cells was not too different from the control, while Ca²⁺-ATPase location presented differences in plasmalemma and Ca-sites. These changes are perhaps connected with the membranes permeability breaking and affect the plant cells adaptation to the influence of hypogravitation.     

The role of weightlessness in the genetic damage from preflight gamma-irradiation of organisms in experiments aboard the Salyut 6 orbital station

The effect of weightlessness on chromosomal aberration frequency in preflight irradiated $\text{Crepis capillaris}$ seeds, on the viability, fertility and mutation frequency in $\text{Arabidopsis thaliana}$, and on the frequency of nondisjunction and loss of X chromosomes in preflight irradiated $\text{Drosophila melanogaster}$ gametes was studied aboard the Salyut 6 orbital station. The following effects were observed: a flight-time dependent amplification of the effects of preflight

-irradiation in $\text{A}$. $\text{thaliana}$ with respect to all the parameters studied; unequal effects in seeds and seedlings of $\text{Crepis capillaris}$; and a significant increase in the frequency of nondisjunction and loss of chromosomes during meiosis in $\text{Drosophila}$ females. These observations are discussed in terms of the data of ground-based model experiments and flight experiments with a different time of exposure of objects to weightlessness. An attempt is made to elucidate the role of weightlessness in the modification of ionizing radiation effects.     

On different sensitivities of microorganisms to lowered gravitation

The influence of lowered gravitation on biomass and CO₂ production in $\text{B.megaterium}$, a xerophyte, and $\text{Spirillum azotocolligens}$, an aqueous spirillum, in liquid nutrient medium on a horizontal clinostat at 0.1 $\text{g}$ has been studied. As controls we considered: 1) growth under stationary conditions of cultivation with test tubes oriented horizontally; 2) growth on a synchronously revolving centrifuge; and 3) growth on a swing with stirring. A horizontal clinostat at 0.1 g stimulates biomass production and CO₂ release in $\text{B.megaterium}$ as compared with the controls. $\text{Spirillum azotocolligens}$ growth is reduced as a result of clinostating. The best development and CO₂ production are observed under stationary conditions. The results do not support the assumption that microorganisms living in water are more resistant to lowered gravitation than those living in soil.     

Evidence for mass-loading of the Venus magnetosheath

The observed magnetic field configuration in the Venus magnetosheath contains information about the solar wind mass-loading processes occurring as a result of the extension of the neutral atmosphere into the magnetosheath. In this paper, magnetic field signatures of various mass-loading processes are discussed and experimental results from the Pioneer Venus Orbiter magnetometer experiment are examined for evidence of these signatures. The data suggest that the ?$\text{V}$X$\text{B}$ acceleration process, stochastic pickup of ionospheric ions, and $\text{J}$X$\text{B}$ force “scavenging” at the ionopause all occur at various times.     

The state experiment — mesospheric dynamics

The $\text{ST}$ructure and $\text{A}$tmospheric $\text{T}$urbulence $\text{E}$nvironment (STATE) experiment was conducted during the second week of June 1983 at Poker Flat Research Range, Alaska. The measurements focus on a study of the middle atmosphere dynamics by comparison between in-situ probe measurements and MST radar measurements. Rocket launchings were conducted at three periods which were selected by monitoring the doppler velocity spectra of the MST radar.The STATE program has included the efforts of several scientists in planning and carrying out the ground-based and rocket measurements. An overview of the program is given together with some preliminary results. The regions in intense backscatter signals detected by the MST radar are shown to correlate with large irregularities in the electron profiles measured.     

Standard data procedures for future space projects

After a general definition of data- and instrument autonomy and an introduction to the End-to-End Data System concept the future guidelines for “Packet Telemetry and -Telecommand” are overviewed. These and other guidelines have been initiated by a NASA/ESA working group and further developed by an international “$\text{C}$onsultative $\text{C}$ommittee for $\text{S}$pace $\text{D}$ata $\text{S}$ystems” (CCSDS), coordinated with 6 space agencies. The status of these documents is reviewed, especially the document on Packet Telemetry, which has reached a mature stage. A pilot project, $\text{A}$utonomous $\text{P}$ayload $\text{C}$ontrol (APC), for the study and the demonstration of these new procedures is introduced shortly.     

Human adaptation to simulated gravitational fields

We present the results of manned studies in which test subjects were exposed to simulated zero $\text{g}$ (water immersion or head-down tilt at ?6°) and head-to-feet acceleration. The findings give evidence that humans have different individual tolerances to an acceleration of +3 G_z after exposure to zero $\text{g}$, whether simulated by immersion or by head-down tilt. The paper discusses the functional relationship between water balance and cardiac output in the establishment of adaptive reactions to simulated zero $\text{g}$.     

Biological investigations aboard the biosatellite Cosmos-1129

Experiments on insects, higher plants and lower fungi were carried out aboard the biological satellite Cosmos-1129, in Earth orbit, from 25 September to 14 October 1979. The main objective of these experiments was to gain more profound knowledge of the effect of weightlessness on living organisms and to study the mechanisms by which these various organisms with different life cycles can adjust and develop in weightlessness. Experiments on insects ($\text{Drosophila melanogaster}$) were made with a view towards understanding gravitational preference in flies, the life cycle of which took place on board the biosatellite under conditions of artificial gravity. Experiments on higher plants ($\text{Zea mays, Arabidopsis taliana, Lycopersicum esculentum}$) and lower fungi ($\text{Physarum polycephalum}$) were performed.     

Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds

We have studied the effects of prolonged (up to 175 days) exposure of $\text{Lactuca sativa}$ seeds to space flight factors, including primary cosmic radiation heavy ions. The data obtained evidence a significant fourfold increase ofs pontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight.     

Cool luminous stars

A broad theme emerging from $\text{IUE}$ and $\text{Einstein}$ observations of cool stars is that magnetic fields control the structure and energy balance of the outer atmospheres of these stars. I summarize the phenomena associated with magnetic fields in the Sun and show that similar phenomena occur in cool luminous stars. High dispersion spectra are providing unique information concerning densities, atmospheric extension, and emission line widths. A recent unanticipated discovery is that the transition lines are redshifted (an antiwind) in β Dra (G2 Ib) and perhaps other stars, which I interpret as indicating downflows in closed magnetic flux tubes as are seen in the solar flux tubes above sunspots. Finally, I classify the G and K giants and supergiants into three groups — active stars, quiet stars, and hybrid stars — depending on whether their atmospheres are dominated by closed magnetic flux tubes, open field geometries, or a predominately open geometry with a few closed flux tubes embedded.     

I.U.E. high resolution observations of hot stars emitting coronal x-rays

The far UV resonance lines of a sample of 21 early-type stars, which were observed in the soft X-Ray band with the $\text{Einstein}$ satellite, are examined using I.U.E. high resolution spectra to search for possible correlation between the X-Ray coronal emission and far UV spectral properties. In particular, those quantities that can give information on the structure of the outer envelope (such as wind terminal velocities, emission-absorption ratios) are measured and compared with the observed X-Ray flux.     

Ultraviolet spectroscopy of cometary comae: An update

Since its launch in 1978 the $\text{International Ultraviolet Explorer}$ ($\text{IUE}$) satellite observatory has been used to record ultraviolet spectra of nearly two dozen comets. These observations have been applied principally to studies of the composition, chemistry and evolution of the gaseous coma and more recently, with the substantially increased data base, to comparative analyses. The observations of Comets Bowell (1982 I) and Cernis (1983?) at a heliocentric distance of ≈ 3.4 AU show these two comets to be virtually identical and pose problems for water ice vaporization models. The most significant recent result from $\text{IUE}$ was the discovery of S₂ in the Earth-approaching comet IRAS-Araki-Alcock (1983d) and the use of the S₂ emission as a monitor of short-term variations in cometary activity. In early 1984, periodic comet Encke was observed for the second time by $\text{IUE}$, this time post-perihelion.     

Ralicon anodes fabricated by electron beam lithography for image photon counting detectors

The Anger wedge and strip anode event location system developed for microchannel plate image photon detectors at the Space Sciences Laboratory of the University of California, Berkeley, has been extended in the present work by the use of electron beam lithography (EBL). Computer-aided design methods have been used to develop several types of RALICON ($\text{R}$eadout $\text{A}$nodes of $\text{Lit}$hographic $\text{Con}$struction) for use in photon counting microchannel plate imaging detectors. These anodes are suitable for linear, two dimensional or radial position measurements and they incorporate novel design features made possible by the EBL fabrication technique which significantly extend their application relative to published wedge-strip anode designs.     

V.L.A. observations of flare build-up in coronal loops

Very Large Array (V.L.A.) measurements at 20 cm wavelength map emission from coronal loops with second-of-arc angular resolution at time intervals as short as 3.3 seconds. The total intensity of the 20 cm emission describes the evolution and structure of the hot plasma that is detected by satellite X-ray observations of coronal loops. The circular polarization of the 20 cm emission describes the evolution, strength and structure of the coronal magnetic field. Preburst heating and magnetic changes that precede burst emission on time scales of between 1 and 30 minutes are discussed. Simultaneous 20 cm and soft X-ray observations indicate an electron temperature $\text{T}{}_{\mathrm{e}}\textcolor{red}{}\text{2.5 × 10}{}^7\text{K}$ and electron density $\text{N}{}_{\mathrm{e}}\textcolor{red}{}\text{10}{}^{10}\text{cm}{}^{\mathrm{?3}}$ during preburst heating in a coronal loop that was also associated with twisting of the entire loop in space. We also discuss the successive triggering of bursts from adjacent coronal loops; highly polarized emission from the legs of loops with large intensity changes over a 32 MHz change in observing frequency; and apparent motions of hot plasma within coronal loops at velocities V > 2,000 kilometerspersecond.     

Stereoscopic observations from meteorological satellites

The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk $\text{et al.}$ [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner $\text{et al.}$ [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler $\text{et al.}$ [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated.Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the two satellites. A general solution for accurate height computation depends on precise navigation of the two satellites. Validation of the geosynchronous satellite stereo using high altitude mountain lakes and vertically pointing aircraft lidar leads to a height accuracy estimate of ± 500 m for typical clouds which have been studied. Applications of the satellite stereo include: 1) cloud top and base height measurements, 2) cloud-wind height assignment, 3) vertical motion estimates for convective clouds (Mack $\text{et al.}$ [13], [14]), 4) temperature vs. height measurements when stereo is used together with infrared observations and 5) cloud emissivity measurements when stereo, infrared and temperature sounding are used together (see Szejwach $\text{et al.}$ [15]).When true satellite stereo image pairs are not available, synthetic stereo may be generated. The combination of multispectral satellite data using computer produced stereo image pairs is a dramatic example of synthetic stereoscopic display. The classic case uses the combination of infrared and visible data as first demonstrated by Pichel $\text{et al.}$ [16]. Hasler $\text{et at.}$ [17], Mosher and Young [18] and Lorenz [19], have expanded this concept to display many channels of data from various radiometers as well as real and simulated data fields.A future system of stereoscopic satellites would be comprised of both low orbiters (as suggested by Lorenz and Schmidt [20], [19]) and a global system of geosynchronous satellites. The low earth orbiters would provide stereo coverage day and night and include the poles. An optimum global system of stereoscopic geosynchronous satellites would require international standarization of scan rate and direction, and scan times (synchronization) and resolution of at least 1 km in all imaging channels. A stereoscopic satellite system as suggested here would make an extremely important contribution to the understanding and prediction of the atmosphere.