Power from space: the policy challenge

The scientific community has long embraced the concept of globalized collaboration, recognizing that scientific inquiry knows no borders and that scientific theory transcends nationality. With respect to translating scientific and technological innovation into practical application, however, national, political, and ideological barriers suddenly arise. At a time when the worlds of economics and finance are rapidly globalizing, the world of applied science lags behind — despite increasingly urgent need for global energy solutions. In the context of considering space solar power (SSP) systems, the author contends that these solutions require new ways of determining costs and benefits; that scientific experts should seek active engagement in the policy arena; and that SSP's scientific community has a critical role to play in advocating for consideration of space-based energy solutions.     

Distribution of Plasma Pressure in the Geomagnetic Tail in the Transition Region from Dipole to Quasidipole and Stretched Magnetic Field Lines: Events on October 13, 1995 and March 13, 1996

The results of an analysis of the pressure distribution of the hot magnetosphere plasma and transverse currents in the plasma at distances from 8R _E to 12R _E are presented. The data were taken in the vicinity of the equatorial plane onboard the Interball-1 satellite during its passages on October 13, 1995 and March 13, 1996. The pressure was determined from the measurements of particle fluxes by the CORALL, DOK-2, and SKA-2 instruments. The specific features of this experiment made it possible to calculate the pressure with a high accuracy and to determine the distribution of the magnetostatically equilibrium currents in the plasma. It is shown that at the parts of the monotonous increase of the pressure in the earthward direction one can detect regions of plateau in the plasma pressure. A possible origin of the small-scale variations and regions with plateau are discussed. A comparison of the measured pressure profiles with the pressure profiles in the Tsyganenko and Mukai-2003 model is performed. Transverse currents flowing in the plasma are calculated assuming magnetostatic equilibrium.     

Measurement of Vibration Microaccelerations onboard the Mir Orbital Station Using the VM-09 System of Accelerometers

The results of processing the data of measurements of microaccelerations, carried out onboard the Mir orbital station using the Russian VM-09 system of accelerometers, are described. The system was developed by the Composite Research-Production Association. The sensitivity of this system was 10^–4 m/s²; its frequency band had limits from a few tenths of a hertz up to 100 Hz. The measurements were carried out in the real-time mode of data transmission to the Earth, when the orbital station flew over the telemetry data receiving point. The instrument's sampling rate was 200 measurements per second, and the length of a continuous run of measurements did not exceed 10 min. The following problems are considered in the paper: (1) isolation of cyclic trends from the measurement data; (2) estimation of spectral density of the data component with a continuous spectrum; and (3) low-frequency filtration of the measurement data     

Evolution of the Orbit of an Earth Satellite with a Solar Sail

The efficiency of using the light pressure of solar radiation for increasing the semimajor axis of the orbit of an Earth Satellite carrying a solar sail is estimated. The orbit is nearly circular and has an altitude of about 900 km. The satellite is in the mode of single-axis solar orientation: it rotates at an angular velocity of 1 deg/s around the axis of symmetry, which traces the direction to the Sun. This mode is maintained by the solar sail, which serves in this case as a solar stabilizer. The following method of increasing the semimajor axis of the orbit (which is equivalent to increasing the total energy of the satellite's orbital motion) is considered. On those sections of the orbit, where the angle between the light pressure force acting upon the sail and the vector of geocentric velocity of the satellite does not exceed a specified limit, the sail is functioning as a solar stabilizer. On those sections of the orbit, where the above-indicated angle exceeds this limit, the sail is furled by way of turning the edges of the petals towards the Sun. Such a control increases the semimajor axis by more than 150 km for three months of flight. In this case, the accuracy of solar orientation decreases insignificantly.     

Statistical Relationships between Solar, Interplanetary, and Geomagnetic Disturbances, 1976–2000: 2

In this paper we continue the analysis of the influence of solar and interplanetary events on magnetospheric storms that was started in [1]. Two data sets are additionally analyzed in the present study: solar flares of importance M5 and greater in 1976–2000 and halo CMEs observed by the SOHO spacecraft during the period of 1996–2000. It is demonstrated that the statistical characteristics of the new set of flares and of that analyzed before in [1] differ little, while the geoeffectiveness of the halo CMEs turned out to be much less than that of the previously published CMEs.     

Radiation Electrification of Spacecraft Leeward Surfaces by Auroral Electrons in the Ionosphere

A methodology of the physical modeling of radiation electrification of the leeward surfaces of the materials used to construct space vehicles by auroral electrons, when the vehicles are flown supersonically around by the ionospheric plasma at low and middle heights, is developed. Based on laboratory modeling, numerical experiments, and in situ observations, the dependencies of charging levels and equilibrium potentials on the ratio of the auroral electron density to the positive ions in the near wake behind the body and in the undisturbed plasma are determined.     

Life support system development in West Germany

The delivery of fully qualified Environmental Control and Life Support System (ECLS) flight hardware for the Spacelab Flight Unit was completed in 1979, and the first Spacelab flight is scheduled for mid 1983.

With Spacelab approaching its operational stage, ESA has initiated the Follow-on Development Programme. The future evolution of Spacelab elements in a continued U.S./European cooperation is obviously linked to the U.S. STS evolution and leads from the sortie-mode improvements (Initial Step) towards pallet systems and module applications in unmanned and manned space platforms (Medium and Far Term Alternatives).

Extensive studies and design work have been accomplished on life support systems for Life Sciences Laboratories (Biorack) in Spacelab (incubators and holding units for low vertebrates).

Future long term missions require the implementation of closed loop life support systems and in order to meet the long range development cycle feasibility studies have been performed. Terrestrial applications of the life support technologies developed for space have been successfully implemented.     

Changes in the vestibular function during space flight

An analysis of observations and investigations carried out in space flight has shown that some cosmonauts and astronauts have experienced vestibular disorders during the transition to weightlessness. Vestibular-sensory disorders include: Spatial illusions (the feelings of falling down, being in an upside-down position, the sensations of rotation of the craft or the body) and vertigo occurring during the onset of the orbital flight and head movements; Feelings, similar to those experienced in response to Coriolis accelerations on the Earth, which occasionally develop in weightlessness during the spacecraft rotation upon abrupt head and body movements and restrained feet; Feelings "of the load on the vestibular analyser which is unlike any Earth-bound effects" upon abrupt head movements during the first hours of an orbital flight and "a prolonged movement" during the switch-off of thrusters in weightlessness. Vestibular-vegetative disorders comprise a complex of symptoms similar to those of motion sickness: loss of appetite, stomach awareness (12%), hypersalination, nausea (9.6%) and vomiting (4.8%). Soviet studies suggest that the vestibular tolerance to the flight effects depends on the natural stability and training to the cumulative effect of adequate vestibular stimuli. This has been used in the development of the system of vestibular selection. Changes in the vestibular function seem to play the major role in the development of motion sickness in weightlessness, extra-labyrinthine factors being contributory. The current hypotheses have not yet been adequately confirmed in experiments. A detailed physiological analysis allows the conclusion that the decisive factor in the development of motion sickness may be the disturbance of the function of analysers responsible for spatial orientation which take the form of sensory conflicts as well as an altered reactivity of the organism due to the hemodynamic rearrangement.     

Forecasting of the Total Electron Content at a Single Location

The autocovariance prediction method previously used for the forecast of VI derived ionospheric characteristics has been used for forecast of one of the most important ionospheric—the total electron content (TEC)—at single locations. Quiet and disturbed conditions at different European stations were studied in regard to clarify the forecasting capabilities of the method for determination of the TEC. The accuracies of the method achieved in dependence on the time range of the forecast are demonstrated.     

Results of Space-Flight Tests of the Vibration-Protective Platform VZP-1K

The data of microacceleration measurements performed onboard the Mirstation are analyzed. The data were taken while testing the passive vibration-protective platform VZP-1K developed by the NPO Kompozit. We have processed the results of simultaneous microacceleration measurements on the vibration-protective platform and on the station body close to the platform. Two sets of the French equipment Microaccelerometer were used for these measurements. It was found that the platform reduces the vibrational component of microaccelerations in the band of frequencies above 3 Hz by more than a factor of 10. In this case, all harmonics with large amplitudes are damped by a factor of 50 and more, and some harmonics with small amplitude are damped only by a factor of 10. In the band 0.3–0.6 Hz (close to natural frequencies of the platform), the several-fold increase in amplitude of the vibrational component of microaccelerations is observed, but since the initial values of this amplitude in all performed experiments were small, the above indicated increase practically has not decreased the vibration-protective properties of the platform. The estimations of natural frequencies and damping coefficients of the platform found as a result of data processing of microacceleration measurements made during its free oscillations are obtained. The dependence of frequencies on the amplitude of oscillations is revealed for one mode, which testifies to appreciable nonlinear effects.