Motion of a descent capsule relative to its center of mass when deploying the orbital tether system

The spatial motion relative to the center of mass is considered for a capsule on an elastic tether, when it is unrolled from a spacecraft by a special program. The spacecraft is in a circular orbit and oriented relative to the local vertical, which is guaranteed by operation of its own stabilization system. Angular motion of the capsule relative to the tether direction is studied, and the main factors influencing the stability of this motion are analyzed. An approximate quasi-linear mathematical model of the capsule attitude motion is obtained, which allows one to estimate the influence of major disturbances of its motion. The results of numerical simulations are presented for characteristic cases of the capsule motion.     

variations of the atmospheric chemical composition in the earths’s polar regions after solar proton flare on July 14, 2000 (photochemical simulation)

Altitude—temporal cross-sections q(z, t) of atmospheric ionization rates by solar protons above the polar regions were calculated using the GOES-10 satellite data on solar proton fluxes for the period of solar proton flare (SPF) on July 14, 2000. The values of q(z, t) were used further in calculations of variations of the atmospheric chemical composition during the flare in the northern and southern polar regions (70°N and 70°S) by two different 1D photochemical models of the atmosphere (neutral and charged components). The calculation results have shown considerable variation of the ozone content after SPF: a decrease of [O3] was about 80% at altitudes of 65–75 km above northern and 25% in the layer of 55–65 km above the southern polar region. Such decrease of the ozone content is a result of reactions with [NO] and [OH] whose concentrations have grown substantially during SPF. According to calculations, the increase of electron concentration during SPF has reached 3–4 orders of magnitude at altitudes of 50–80 km. A comparison of the calculation results with the observational data on [NO], [NO2], and [O3] from the UARS and HALOE satellites for 70°N have shown a good qualitative correspondence, however, for variations of nitric oxides there are quantitative discrepancies.     

Periodic solutions in three-dimensional restricted three-body problem: 2. Loss of symmetry at the 1:1 resonance

Within the framework of the circular restricted three-body problem a family of inverse periodic orbits around the two attracting bodies (the Egorov’s family) and families generated by it at the 1:1, 2:1, and 3:1 resonances for three-dimensional orbits in the Sun-Earth and Earth-Moon systems are considered. Their relationship with families generated by orbits around the libration points L ₁, L ₂ and L ₃ is investigated. One of the families contains periodic solutions that seem promising as possible orbits for the space radio telescope of the Millimetron project.     

Solar, geomagnetic and cosmic ray intensity changes, preceding the cyclone appearances around Mexico

Recently it has been suggested that there exist specific changes in the cosmic ray intensity and some solar and geomagnetic parameters during the days, preceding the hurricane appearances over the North Atlantic Ocean. To understand better these phenomena, data for all hurricanes born not only over the Atlantic but also over the Pacific waters in the last 55 years that hit the Mexican borders were elaborated. As basic hurricane parameters the maximum rotational velocity and the estimated total energy were used. To avoid any interference all hurricanes, overlapping the preceding ones with more than 20 days were not included. Then the behavior of the cosmic ray (CR) intensity, the sunspot (SS) numbers, and the geomagnetic parameters (AP) and (KP) in 35 days prior and 20 days after the cyclone start were investigated. The CR, SS, AP and KP showed much more intensive disturbances in the periods preceding and following the hurricane appearance. For SS this disturbance gradually increase with the hurricane strength. A characteristic peak in the CR intensity appears before the hurricane start. But its place varies between 5 and 20 days before that start. Specific changes were observed in the SS. For major hurricanes they begins sometimes more than 20 days in advance. The AP and the KP show series of bursts, spread over the whole period of 30 preceding days. The obtained results from the performed correlational analysis are enough interesting to motivate a further statistical analysis with more precise techniques: in particular a common periodicity of 30 years found in the number of tropical storms landing into Mexico, the averaged rotational wind velocity and the ACE must be studied in connection with the solar Hale cycle. Using coherence wavelet spectral analysis we present a comparative study between one terrestrial and one cosmophysical phenomena that presumable influence hurricanes development: African dust outbreaks versus cosmic rays for all North Atlantic tropical cyclones. It is shown that the cosmophysical influence cannot be considered as a negligible effect.     

A system of flight data acquisition,processing, and recording

A system for recording and analysis of flight information including the technical condition of a control object and the state of its controller’s health in real time aboard a flight vehicle and in ground-based air traffic control centers is described.     

Gravitational maneuvers as a way to direct small asteroids to trajectory of a rendezvous with dangerous near-Earth objects

A possibility to prevent collisions with the Earth of dangerous celestial bodies by directing at them small asteroids is considered. It is proposed to solve this problem using a gravitational maneuver near the Earth.     

The United Kingdom Atomic Energy Authority RIPPLE Program

This paper reviews the work carried out at the Atomic Energy Research Establishment (AERE) since 1963 in connection with the development of isotope-powered thermoelectric generators, known as RIPPLEs. It outlines the criteria considered for the selection of strontium 90 as the radioisotope, the design of the generators, the choice of material for the biological shield, and the development of the thermal insulation. It briefly discusses the voltage conversion system employed and states safety design considerations. The paper concludes by discussing the effect of efficiency on the cost of generators and shows typical costs curves.     

Simulation of the test stand gas-liquid ejector operation

Based on the data of numerical simulation of the test stand gas-liquid ejector operation, the fields of gasodynamic flow parameters in the gas flue channel are determined. The test stand operation in real time and processes of interaction between the flow of combustion products and neutralizing liquid are also analyzed.     

On the asteroid hazard

The concept of “space patrol” is considered, aimed at discovering and cataloging the majority of celestial bodies that constitute a menace for the Earth [1, 2]. The scheme of “optical barrier” formed by telescopes of the space patrol is analyzed, requirements to the observation system are formulated, and some schemes of sighting the optical barrier region are suggested (for reliable detection of the celestial bodies approaching the Earth and for determination of their orbits). A comparison is made of capabilities of electro-jet engines and traditional chemical engines for arrangement of patrol spacecraft constellation in the Earth’s orbit.