A Robust Control Algorithm of a Descent Vehicle Angular Motion in the Earth’s Atmosphere

A new approach to synthesize a robust controller for the angular motion of the Earth lander by decomposition method of output modal control is proposed. A universal analytical solution for the problem of stabilizing the angular position of the lander is obtained. A comparative analysis of the presented algorithm with the currently used onboard algorithm for descent control of the manned spacecraft Soyuz is carried out. The advantages of the new algorithm relative to the existing algorithm are presented, both in terms of stabilization accuracy and the consumption of the working fluid of the control motors.

SPACECRAFT RELIABILITY CALCULATIONS USING STATISTICAL REGULARITIES IN OCCURRENCES OF FAILURES IN DEVICES, UNITS AND ASSEMBLIES DURING THEIR OPERATION

The paper addresses reliability analysis of manned spacecraft with the use of statistical regularities in in-flight failures of their devices, units and assemblies. It formulates validity criteria for using a device failure in reliability analysis, proposes a method for analyzing and classifying failures which enables factoring in different types of failures in reliability analyses. It considers a hypothesis of the absence of statistically significant differences in probabilities of individual valid failures and demonstrates the feasibility of its adoption with the use of dispersion analysis. A method is developed for evaluating product reliability using a functional relationship between reliability and the number of failures occurring in flight which makes it possible to significantly simplify reliability analysis for complex products, to establish the number of in-flight failures that is acceptable from the standpoint of the product reliability requirements, to study various product architectures from the standpoint of reliability criteria. It proposes a method for evaluating the lower boundary for the probability of manned spacecraft completing their missions based on the failure modes, effects and criticality analysis, and demonstrates the feasibility of optimizing the product redundancy scheme based on the fault tolerance requirements. Key words: manned spacecraft, flight, failure, fault tolerance, classification of failures, reliability, probability of failure-free operation, statistical analysis, dispersion analysis.

Historical Aspects of Organizing and Conducting Training of Cos-monauts for Space Flight on Soyuz-T Transport Vehicle. (Memoirs of Crew Trainer V.I. Vasilyev).

The 5th of June 2021 will mark 41 years since the launch of the first manned spacecraft of the Soyuz T series. The difficulty of training to fly on the Soyuz T spacecraft was that the entire training base, all descriptions and guides necessary to study the ship and prepare the crews in a regular way, lagged behind the pro-cess of vehicle designing. In the course of the first trainings and flights, the forms, methods and training programs were worked out. The problem of re-training cosmonauts who performed flights on the Soyuz spacecraft was particu-larly critical.

Current State and Prospects of Human Space Exploration With the Involvement of Private Companies.

The paper describes the prospects for human space exploration. The growing role of private companies in the design of manned spacecraft is shown. An overview of these companies and their technological developments is given. The importance of international cooperation in space exploration is empha-sized.

Results of re-using Soyuz manned spacecraft descent thrusters

This paper presents the results of re-using the descent thrusters of the descent module of Soyuz manned transportation spacecraft. A description of the thrusters design, their performance and configuration on the descent module is provided. Based on statistical evidence on the remaining life of thrusters, it was stated that the remaining lifetime is more than one and a half times higher than the required value for re-use. The results of stand-alone tests of catalytic packages and thrusters are presented to confirm the re-usability. It was demonstrated that the performance of thrusters when being re-used remain within the limits allowed by the design documentation. A description of the post-flight maintenance program is presented, based on which results a certificate of fitness for thruster re-use is issued. The statistics of the re-use of the descent thrusters is provided. As of June 1, 2020, 40 thrusters were admitted for re-use. All thrusters operated with no comments. Key words: descent module, low-thrust jet engine, hydrogen peroxide, re-use.

New Approaches to the Design of a Lunar Station for Servicing Automatic and Manned Spacecraft

The purpose of the study was to tackle the problem of creating an orbiting lunar station in a circular low orbit with an altitude of 100 ... 150 km. The study shows that this task should be considered not as the advantage-disadvantage ratio but as the development of a specific design solution - in a methodological design approach. Meanwhile, it is necessary to take into account the strategic importance of the orbiting lunar station for the entire process of the exploration of the Moon. The station should be created not only for manned expeditions but also for automatic spacecraft. The paper describes the methodological approaches to the design of space stations, namely the design methods which imply opportunities and tasks identification, gives examples of applying these methods, points out their shortcomings, including the lack of accounting for changes in design problems. As a result of studying the problem, we propose a design method that takes into account the dynamics of changing the tasks of the designed object, i.e. the tasks that arise during the Moon exploration. The study gives an enlarged description of the method, where the starting point is many different scenarios for the design of an object, i.e. the orbiting lunar station. Relying on the proposed method, we preliminarily designed the station and found that its design determines the design of its modules. The study substantiates the development of several standard (serial) space modules designed to perform basic functions in space flight. The combination of such modules within the framework of an open architecture allows the station to quickly adapt to new tasks and operate for an unlimited time - theoretically, without a time limit.