The glow of the night ionosphere due to energetic ion beams

This paper discusses photometric measurements made of the ionospheric excitation of the line $\text{λ = 5577}\text{A}\text{?}$ at the time of electron beam injection from a rocket into the Earth's ionosphere. The gradual increase of the glow intensity per impulse occurs due to accumulation of the energy of excited states of N₂(A³Σ⁺_u) and O(′S) during their lifetimes. The large disturbed zone in the near-rocket environment (size >500 m) is connected via the interaction of ions accelerated in the rocket potential field with ionospheric components. The glow intensity modulation is observed at a height of ～98 km during the electron beam injection simultaneously with the ignition of the beam-plasma discharge (BPD). The intensity minima are explained by a decrease of the energy of accelerated ions due to effective neutralization of the rocket body by the BPD plasma. The height profile of the glow intensity revealed two maxima at heights of ～103 km and ～115 km. The second maximum (at ～115 km) indicates that, at these heights, both collision and collision-free mechanisms of accelerated ion energy transport to ionospheric components exist.     

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.     

Space observations of trace gases for climate studies

The paper considers the importance of trace gases in modulating the fluxes of solar and terrestrial radiation in the Earth's atmosphere, and the influence of these effects on the long-term climate. Present and future capabilities for observing and monitoring trace gases from spacecraft are surveyed.     

What is climate?

The present meaning of the word $\text{climate}$ evolved simultaneously with the formulation of research priorities which are regarded as necessary to explore the causes and, consequences of observed environmental changes. Climate can be understood in its widest sense as the totallity of influences to which the biosphere is exposed. Of primary interest are changes of these environmental conditions which are caused by the variability of the $\text{climate system}$. This expression is used in the sense of a physical system in which energy conversions take place, and which is forced, e.g. by the solar input, geologic events and man's activity. The climate system is composed of five major subsystems: atmosphere, hydrosphere, land surfaces, cryosphere and biosphere. These subsystems interact in a complex non-linear manner in different time scales. Major climate determining processes are outlined and the research priorities are discussed, which are regarded essential to investigate them and their interactions.     

Orbital dynamics of magnetospherically trapped lunar ejecta

$\text{In situ}$ measurements by dust experiments on HEOS II showed significant enhancement of fluxes for submicron particles. Recent studies have shown that lunar ejecta in this size range can, in a highly simplified model, be trapped in the earth's magnetosphere. The present work is a more detailed study of the dynamics of lunar ejecta in the magnetosphere. The particle size ranges for which the guiding center approximation is valid, for which corotation is negligible, and for which electromagnetic forces dominate gravitational forces have been calculated. Temporal details of charge acquisition by ejecta in the plasmasphere are considered.     

Dust motion in Jupiter's tilted magnetic field

We outline an analytical method for studying the motion of charged dust particles that orbit an oblate planet having a tilted, offset, dipolar magnetic field. Our computed trajectories closely mimic previous numerical results; equilibrium dust potentials must be less then 10 volts or the Jovian ring would be thicker than observed. We identify several $\text{Lorentz resonances}$, where the periods of components of the Lorentz force, as seen by a reference particle moving in the equatorial plane, match the particle's orbital period; several seem to be near observed features of the Jovian ring system.     

Prospecting in glaciated terrain-integrating airborne and Landsat MSS

The effects of a glacially enriched zone of trace elements on soils and vegetation in the Thetford Mines area of Quebec were investigated using ground information plus digital Multispectral Scanner (MSS) data from airborne and Landsat sensors. The enriched zone was developed during the last glaciation when a southeastward flowing glacier eroded and dispersed an ultrabasic outcrop that had anomalous levels of Ni, Cu, Co, Cr, Mg and Fe.The dispersal train of enriched trace elements was detectable over an area at least 70 × 15 km ‘down-ice’ from the outcrop. In this zone total Ni concentrations in the soil ranged from background levels of 10 ppm to levels in excess of 1800 ppm. The dominant tree species, $\text{Abies}$$\text{balsamea}$ (balsam fir) and $\text{Picea glauca}$ (white spruce) reflect the soil anomaly with higher concentrations of trace elements in their tissue and lower concentrations of chlorophyll.An unsupervised enhancement of Landsat imagery showed that a tonal discontinuity was caused by a vegetation segregation related to the heavy metal enrichment soils. A detailed study based on Landsat MSS data was able to establish regional patterns of chlorophyll production by certain plant species closely related to the ultrabasic dispersal train. Multi-channel airborne MSS data confirmed the Landsat soil-plant patterns.     

Climate studies from satellite observations: Special problems in the verification of earth radiation balance,cloud climatology,and related climate experiments

A body of techniques that have been developed and planned for use during the Earth Radiation Budget Experiment (ERBE), the International Satellite Cloud Climatology Project (ISCCP), and related climate experiments of the 1980's are reviewed. Validation and verification methods must apply for $\text{systems}$ of satellites. They include: (1) use of a normalization or intercalibration satellite, (2) special intensive observation areas located over ground-truth sites, and (3) monitoring of sun and earth by several satellites and/or several instruments at the same time. Since each climate application area has a hierarchy of user communities, validation techniques vary from very detailed methods to those that simply assure high relative accuracy in detecting space and time variations for climate studies. It is shown that climate experiments generally require more emphasis on long-term stability and internal consistency of satellite data sets than high absolute accuracy.     

A transient MHD model applicable for the source of solar cosmic ray acceleration

A two-dimensional, time-dependent magnetohydrodynamic (MHD) model is used to describe the possible mechanisms for the source of solar cosmic ray acceleration following a solar flare. The hypothesis is based on the propagation of fast mode MHD shocks following a sudden release of energy. This model has already been used with some success for simulation of some major features of type II shocks and white light coronal transients. In this presentation, we have studied the effects of initial magnetic topology and strength on the formation of MHD shocks. We consider the plasma beta (thermal pressure/magnetic pressure) as a measure of the $\text{initial}$, relative strength of the field. During dynamic mass motion, the Alfvén Mach number is the more appropriate measure of the magnetic field's ability to control the outward motion. We suggest that this model (computed self-consistently) provides the shock wave and the disturbed mass motion behind it as likely sources for solar cosmic ray acceleration.     

Magnetic flux ropes in the Venus ionosphere: In situ observations of force-free structures?

Force-free magnetic structures with cylindrical geometry appear under a variety of conditions in nature. Filamentary helical magnetic structures are observed to be associated with prominences and flares in the solar atmosphere, and can arise in superconductors and laboratory plasmas. Another example of cylindrical quasi-force-free configurations appears to exist in the Venus ionosphere. Magnetic flux ropes with diameters of ～20 – 30 km have been observed by the Pioneer Venus Orbiter to be a nearly ubiquitous feature of the dayside Venus ionosphere. Models of flux ropes suggest that many of these structures tend to be quasi-force-free, i.e., $\text{J}$×$\text{B}$～0, while others are correlated with pressure variations in the ambient thermal plasma, $\text{J}$×$\text{B}$=-?(nkT).     

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.     

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.     

Cometary dust observations by optical in-situ methods

Remote optical observations of comets provide information only along the whole line of sight and require some assumptions to be interpreted. Due to the advent of cometary space missions, a two-step strategy has been defined to derive without any assumption spatial distribution and physical properties of dust by in-situ optical observations. First, an $\text{Optical Probe Experiment}$, suitable for a fast fly-by, should provide passive in-situ measurements in the direction of the approaching (or receding) comet near encounter; by suitably differencing such observations, the brightness and polarization per $\text{unit volume}$ can be recovered along the trajectory of the spacecraft. Secondly, a $\text{Light Scattering Dust Analyzer}$, suitable for a rendez-vous mission, should permit the determination of the scattering properties of $\text{individual particles}$. Both experiments also provide a connecting link between non-optical in-situ measurements (from mass spectrometers or impact detectors) and remote optical observations.     

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.