Biological studies of martian soil analogues

Results of the study of the influence of Martian soil analogues, both as described by American scientists and as prepared by us, and of hydrogen peroxide on the viability of microorganisms are presented. The experiments were carried out using mixtures of soil analogues with desert soil and black earth (chernozem) samples, and pure cultures of microorganism. Microorganisms capable of withstanding a concentration of hydrogen peroxide in the medium as high as 1.5–2.0% were isolated. None of the 40 strains of microorganisms studied, all belonging to different systematic and physiological groups, exhibited growth inhibition on solid media in the presence of Martian soil analogues. In view of the fact that Martian soil cannot contain microorganisms in great quantities, we suggest using electroadsorption for their concentration, to make detection reliable. A device was designed for this purpose, using the principle of electroadsorption on a polarisable carrier (sterile cotton wool or cheesecloth). The concentrated suspension of microorganisms thus obtained was then characterized by various physicochemical methods.     

Experiments with injection of powerful plasma jet into the ionosphere

This paper describes two rocket experiments “Aelita” with high power lithium plasma injection. The results of onboard magnetometer, massspectrometer, photometer, plasma, corpuscular and ground radar measurements are given. Dynamics and structure of plasma formation are discussed.     

Radar Doppler Spectra of Turbulent Ionized Wakes

The evaluation of the double convolution integrat involved in the expression of the radar response to scattering from a turbulent ionized wake is simplified by the approximation technique presented here, so that the Doppler spectrum parameters can be explicitly expressed in terms of the wake characteristics.     

Corrections of Satellite Positions in Near-Real Time

The influence of sudden increases of electron content on the accurate determination of the position of a satellite is investigated based on a spherically stratified ionospheric model. Using the total electron content information from Faraday rotation measurements, a procedure is presented whereby the corrections of satellite position due to the unpredicted electron increase can be accounted for without the need to know the spatial distribution of the additional electrons.     

Performance Degradation Due to Specular Multipath Intersymbol Interference

Plots of performance degradation are used to compare the effects of fading and intersymbol interference in a two- component specular multipath digital communications channel. Similar plots are then used to compare two practical receivers designed to combat the interference. Degradation plots are shown to allow easy identification of each receiver's range of usefulness, as well as identification of variance bounds demanded of channel parameter estimates which the receivers require.     

Sensitive detection of narrowband pulses

Highly monochromatic signals, such as TV carriers, can be detected sensitively by using a narrow filter (b < or = 1 Hz) and performing power accumulation on its output. If instead a low-duty-cycle pulsed signal of the same total energy is present, the sensitivity of a square law device, followed by a thresholding operation (to eliminate most samples containing only noise), followed by the algorithm to be described, is greater by about 7 dB in typical cases. This is particularly interesting to SETI because such a pulsed signal is exactly what is sent by a rotating beacon with a directional antenna. Such a pulsed signal is, therefore, a good candidate for an extraterrestrial beacon. Software for detecting this signal type is now ready for field testing with the NASA Multichannel Spectrum Analyzer (MCSA).     

Long term observations of Cyg X-3 with Vela 5B

We present long-term (1969–1979) observations of Cygnus X-3, obtained by the Vela 5B satellite. The 3–12 keV light curve has 10 day time resolution. Cyg X-3 is a peculiar high-luminosity X-ray source, radiating from the radio region to hard gamma rays of more than 10¹⁶ eV. It has a 4.8 hour period, probably orbital, which is not resolved by our present analysis. Long term periodicities of 17, 20, and 33–34 days have been reported by several authors, and explained as the effects of apsidal motion, precession, or an eccentric orbit. We do not observe the 17 and 33–34 day variations, and set upper limits significantly lower than the reported amplitude of the 33–34 day variation. There is weak evidence for a 20 day flux variation. The light curve shows high and low states which alternate with a characteristic timescale of 1 year. There is no counterpart, at this time resolution, of the giant radio outburst of 1972 September.     

Temperature Cycling Effects on Solar Panels

Temperature cycling for more than 300 cycles and for temperatures down to - 175°C performed on soldered silicon cell assemblies with copper, Kovar, and molybdenum interconnectors showed a wide range in failures depending both upon the materials used and on interconnector thickness and substrate material. The solder fatigue failure rate is strongly dependent on stress level in agreement with analytical predictions.     

A Comparison of Expected Flight Times for Intercept and Pure Pursuit Missiles

The relative merits of intercept and pure pursuit homing are investigated by comparing the expected flight times to a nonmaneuvering target. The analysis is performed for the initial target heading angle uniformly distributed with arbitrary mean and variance. Two specific examples illustrate that intercept homing holds little statistical advantage over pure pursuit homing except when the speed advantage of the missile is very small.