Propulsion of space ships by nuclear explosion

Recent progress in the research on deuterium-tritium (D-T) inertially confined microexplosions encourages one to reconsider the nuclear propulsion of spaceships based on the concept originally proposed in the Orion project. We discuss first the acceleration of medium-sized spaceships by D-T explosions whose output is in the range of 0.1–10 t of TNT. The launching of such a ship into an Earth orbit or beyond by a large nuclear explosion in an underground cavity is sketched out in the second section of the paper, and finally we consider a hypothetical Mars mission based on these concepts. In the conclusion it is argued that propulsion based on the Orion concept only is not the best method for interplanetary travel owing to the very large number of nuclear explosion required. A combination of a super gun and subsequent rocket propulsion using advanced chemical fuels appears to be the best solution for space flights of the near future.From Kosmicheskie Issledovaniya, Vol. 43, No. 1, 2005, pp. 67–75.Original English Text Copyright © 2005 by Linhart, Kravárik.     

The white blood cell line: changes induced in mice by hypergravity.

The effect of hypergravity on the white blood cell (WBC) line of mice was investigated by use of horizontal centrifuge. Several sets of experiments were performed, in which the parameters measured were the WBC and differential cell count in the peripheral blood. In another experiment, lymphocyte counts from the spleen, lymph nodes, and the thymus were measured. The needed samples were taken from the mice during a stay of 7-40 days under a hypergravity of 1.6G. The test groups that were placed on the arms of the centrifuge (1.6G) were compared with stationary control groups (1G) and a rotating control group located at the center of the centrifuge (1G). Such a comparison revealed the test animals to be deficient on all counts, to wit, showing a decrease in total number of WBC's, a decrease in lymphocyte number in the peripheral blood and a decrease in the number of lymphocyte in the spleen and thymus. The decrease of lymphocytes in peripheral blood was characterized by two different slopes--an early and temporary decrease at the first days of the experiment evident in both test and rotating control groups followed by a temporary increase, and a later persistent decrease, evident only in the test group, while in the rotating control lymphocyte counts reverted to normal. There were no significant differences in monocyte or neutrophil counts, except for a temporary increase in the number of neutrophils which peaked on the seventh day. In order to evaluate the effect of hypergravity on restoration of hematopoiesis following hematopoietic suppression, 5-fluoro-uracil (5-FU) was administered i.v. to both the experimental and control mice. Suppression of bone marrow was observed in all groups injected with 5-FU, but while there was later an increase in cell counts in the control groups, there was no such increase in the test group subjected to hypergravity.     

Special features of a digital speckle interferometer for determining vibration characteristics of heavy-loaded elements of an aircraft fuel pump

The results of vibration tests for heavy-loaded elements in the auger-centrifugal stage of an aircraft fuel pump performed with the use of an interference-free digital speckle-interferometer created at the Samara State Aerospace University are presented. The speckle-interferograms of an auger and a centrifugal wheel of the auger-centrifugal pump stage in different conditions of attachment and dynamic loading are given. The data obtained may be of sufficient importance in the development of aircraft fuel pumps for a specified service life.     

Optimization of efficient order service by information unmanned aerial vehicles

We propose a mathematical model and the numerical method for an optimal choice of unmanned aerial vehicles (UAVs) from those being in flight to fulfill a newly received order for monitoring (reconnaissance) of a new region. Examples of using the approach being proposed and main lines of its realization in promising information unmanned aircraft complexes (UAC) are presented.     

Investigation of helicopter maneuverability by the power balance method

The algorithms for calculating available overloads and maneuvers are presented. Nesterov’s loop maneuver is analyzed.     

On application of the theory of face seals with microgrooves to high-speed FV engine rotors

With allowance made for thermoelasticity of working surfaces and inertia forces on the lubricant coat, a hydrodynamic problem is solved for the noncontacting face seals with microgrooves in the high-speed rotors of FV engines. Also shown are the initiation of surface waviness in the zone of lubricant coat fracture and the influence of its amplitude upon the seal characteristics.     

Parametric navigation system synthesis on the basis of a magneto-inertial course transmitter

A technique for the parametric synthesis of the navigation system on the basis of the magneto-inertial course transmitter is proposed; the technique makes it possible to minimize the error scatter in determining the ground speed components, to analyze a nature of the error scatter variation in determining the location coordinates in time, to simulate and further choose regular intervals of using additional data obtained from the radionavigational satellite system.     

Metal creep model with the initial strain discontinuity and functional material constants

It is proposed that curves of metal creep be approximated by the time-relative linear law with the initial creep strain discontinuity; as a result, the solution of initial boundary value rheological problems is considerably simplified and is characterized by the adequate precision with a large service life. The labor intensity of computations is similar to the steady-state creep law. The introduction of functional material constants makes it possible to perform calculations of creep under the action of temperature that is different from the specified one in the basic experiments as well as calculations of nonuniformly heated structure elements.     

The Initial Stage of “Space Debris” Cloud Formation during Planetary Satellite Breakdown

The process of formation of a particles cloud (space debris) during breakdown of the Earth’s Artificial Satellite (EAS) is considered. A system of equations of motion is derived, and its analytical solution in the linear approximation for circular orbits is presented. The distinction between this solution and an exact numerical solution is indicated. The cases of satellite breakdown at the apogee and perigee on an elliptic orbit are also considered, and some characteristics of these processes are compared.__________Translated from Kosmicheskie Issledovaniya, Vol. 43, No. 4, 2005, pp. 269–273.Original Russian Text Copyright © 2005 by Gorelov, Zarubkin.     

Deformation of the Envelope of a Broadband Signal during Propagation through the Martian Ionosphere

The regularities of propagation along the spacecraft-Martian surface-spacecraft path of a broadband Gaussian pulse in the condition of its dispersion distortions are considered in application to the problem of radiowave pulse sounding of the near-surface soil of Mars from onboard a satellite. The Martian night-side ionosphere reduces the energy considerably but does not lead to any distortion of the pulse envelope. At the sounding of a two-layer surface, the ionosphere influence, together with the signal absorption, manifests as the lower limit of the thickness of the upper layer reached for measurements in the scope of the planned experiment [1].