The paper considers an approach to studying the influence of elastic properties of aerospace structures on their relative motion during separation. Based on the assumptions characteristic of the ...process under study, a model is developed that allows for a visual mechanical interpretation: the total motion is decomposed during separation into a portable motion (rotational and translational in solid forms) and small elastic relative vibrations described in a universal modal formulation. Recommendations are given that made it possible to almost completely eliminate the problems associated with elastic vibrations during separation.
A possible way to launch CubeSats is to place them in deployers installed on Progress MS cargo spacecraft. Launching satellites into orbit is potentially feasible both during Progress MS autonomous ...flight and during its stay in the International Space Station. In order for the CubeSats to achieve their mission targets, the separation process requires that they obtain the necessary linear velocities, the angular disturbances obtained be minimized and that the satellites continue to move without collisions. Addressing these issues involves the development of a dynamic model based on the numerical integration of motion equations. Once the model has been verified, taking into account, in addition to the permissible mass-centric and inertial characteristics of the objects, the contact interactions of satellites with the deployer guide rails and the door, a series of statistical calculations are carried out for different launch scenarios, based on the results of which a conclusion about the possibility of implementing the schemes considered is drawn and recommendations are made (in terms of dynamics) on the choice of the most appropriate layout.
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A universal approach to the creation of dynamic models for the disclosure of space structures is proposed, which makes it possible to study current and promising disclosure schemes on a single ...methodological basis. The approach involves consideration of the spatial motion of a structurally complex mechanical system that includes the spacecraft body and the structural elements of the disclosed structure and is under the influence of specific force factors created by the means of disclosure. The proposed approach is considered for the example of the process of opening solar panels, which is one of the key operations of the functioning of spacecraft, the reliability of which directly determines the success of the mission. To determine the forces and moments in the joints of the disclosed structure, a special system of coupling equations is obtained. The proposed approach significantly expands the range of simulated processes of transformation of space structures and allows us to analyze not only the kinematics and dynamics of the disclosed structure, but also to determine the spacecraft perturbations caused by the disclosure process. It can be used not only for practical tasks of selecting the characteristics of the disclosure system, but also for modeling situations that are fundamentally not reproducible in the conditions of ground-based experimental testing.
Equations are obtained, and a model is constructed for studying the dynamics of separation of fairing flaps of rocket and space systems. Based on the assumption that the angular velocity of rotation ...of fairing flaps during separation is small compared to the lower frequencies of their natural vibrations, two independent groups of analytical relations are obtained, one of which describes the spatial motion of the fairing flaps as a whole relative to the launch vehicle, and the second one describes elastic vibrations in the turn section relative to the axes fixed on the carrier. Based on the ratios of the first group, the trajectories of the motion of the fairing flaps in the process of separation are constructed. In the second group of equations, the dependences of the level of excitation of the flap vibrations on the different times of switching on the separation engines and/or the spread of the characteristics of pushers are studied. The mathematical model considered expands significantly the range of problems to be solved and allows for the first time to analyze the simultaneous influence of both types of motion, the spatial motion of the fairing flaps as a whole and the elastic relative vibrations, on the safety of the separation process, which means the guaranteed exclusion of their collisions with both the launch vehicle and the payload. A number of relevant analytical estimates are obtained for calculating the relative motion and the level of vibrations of the flaps during their separation.
The possibility of using chlorophyll fluorescence visualization in practical apple and apricot breeding is considered. Significant influences of water deficit and heat shock on the photosynthetic ...activity of leaves as estimated from their fluorescent images are found. The most sensitive indicator for detecting the degree of drought-induced depression of fruit plants is confirmed to be the effective quantum yield of photosystem II.
A method to assess the gas resistance of woody plants was developed based on the level of inhibition of the photosynthetic activity of leaves exposed to toxic gases in the laboratory and could be ...used to identify plants resistant to environmental pollution for further practical and breeding use. The effective quantum yield of photosystem II was used as an indicator of genotype tolerance. The sensitivity of the indicator was sufficient to differentiate control and experimental variants. The objects under study were ranked according to the degree of gas resistance. Recommendations were given for the practical application of the new method.
An universal approach for building dynamic models of the process of transformable space structures deployment is considered. The calculation results for a solar-powered spacecraft are given as an ...example.
The research was aimed at evaluating sweet cherry forms on a complex of economically valuable traits and the allocation of promising genotypes for further use in breeding and production. The forms of ...sweet cherries grow in Michurinsk city of Tambov region. The study of frost resistance was carried out in laboratory conditions. Annual branches were frosted for 12 hours at -32°C and -35°C. Reproductive buds in all studied forms were characterized by reversible damage (less than 3 points) at temperature regime -32°C and complete death at -35°C. 10-117 form was characterized by -35°C frost resistance in the middle of winter, in which the freezing degree of annual branches tissues and vegetative buds did not exceed 2 points. Over the years of research, elites 4/8-24, 10-115, 7-38, 10-117, 6-87, 4/9-15, 7-5 possessed resistance to moniliosis and coccomycosis (the damage degree not more than 2 points). The highest yield (9.75-9.84 t/ha) on average over three years was shown by forms 4/8-24, 7-38, 7-5. Yield at the control level was noted in forms 6-87, 4/9-15, 10-115. Elite forms 4/9-15, 7-38 were characterized by the largest mass of fruits, significantly exceeding the control variety. The average weight amounted to 7.3 and 7.2 g, and the maximum was 9.4 and 8.4 g respectively. Forms 4/8-24, 4/9-15, 7-38 combined the dessert taste of fruits (tasting assessment of 4.6-4.8 points), very juicy and dense pulp.
The paper proposes an approach to study the influence of the flaps spatial movement as a solid body and the elastic relative vibrations of their structure on the flaps separation process safety, ...which means the guaranteed exclusion of their collisions with both the launch vehicle and the payload. A number of relevant analytical estimates for calculating the spatial relative motion and the level of flaps vibrations during their separation process is obtained.
We propose an easy-to-implement algorithm providing the safe (collision-free) separation of the Soyuz MS crew transfer vehicle from the ports of the Rassvet (MRM-1) and Poisk (MRM-2) mini-research ...modules of the International Space Station at an arbitrary station attitude at the time of separation and angular velocities exceeding the maximum permissible for the current undocking algorithm. A criterion of collision-free separation process is described and a comprehensive mathematical model used for calculation is presented.
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