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V. P. Fedotov

Bio: V. P. Fedotov is an academic researcher from Unitary enterprise. The author has contributed to research in topics: Moon landing & Spacecraft. The author has an hindex of 2, co-authored 6 publications receiving 13 citations.

Papers
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Journal ArticleDOI
TL;DR: An integrated conceptual basis is used to develop multistep terminal algorithms for guidance for the three segments of the descent of a landing module designed for the Moon landing.
Abstract: The paper deals with a choice of the rational trajectory of motion of a landing module designed for the Moon landing, from the moment of its de-orbiting from the near-lunar orbit up to landing. An integrated conceptual basis is used to develop multistep terminal algorithms for guidance for the three segments of the descent.

5 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present the braking profile of a spacecraft making a soft landing on the Moon's surface, including the following four phases: main braking, free fall, repeated braking and descent at a constant speed.
Abstract: Rationale is given for the braking profile of a spacecraft making a soft landing on the Moon’s surface, including the following four phases: main braking, free fall, repeated braking, and descent at a constant speed. Due to the large altitude differential over the braking path in near-polar regions of the Moon, main braking is proposed as a type of trajectory correction impulse using no altimeter. The boundary problem solution and statistical calculations are used to give the potential energy costs and characteristics of the dispersion characteristics for this phase and choose an optimal thrust-to-weight ratio for the phase.

4 citations

Journal ArticleDOI
TL;DR: In this paper, the main braking phase for a soft Moon landing as a form of trajectory correction was studied, and analytical relations for the main parameters were obtained, and the impact of various disturbing factors was estimated.
Abstract: This article continues our study of spacecraft guidance and control for a soft Moon landing (see our article “Main braking phase for a soft Moon landing as a form of trajectory correction”). Rationale is given for the objectives of the subsequent (final touchdown) phases. Analytical relations for the main parameters are obtained, and the impact of various disturbing factors is estimated. A methodology is proposed for calculating the main parameters for the whole braking sequence from the sighting altitude of the main braking phase termination to braking engine thrust and its throttle range.

4 citations

Journal ArticleDOI
TL;DR: For the descent from the pericenter of a prelanding circumlunar orbit a comparison of three algorithms for the control of lander motion is performed.
Abstract: For the descent from the pericenter of a prelanding circumlunar orbit a comparison of three algorithms for the control of lander motion is performed. These algorithms use various combinations of terminal and programmed control in a trajectory including three parts: main braking, precision braking, and descent with constant velocity. In the first approximation, autonomous navigational measurements are taken into account and an estimate of the disturbances generated by movement of the fuel in the tanks was obtained. Estimates of the accuracy for landing placement, fuel consumption, and performance of the conditions for safe lunar landing are obtained.

3 citations

Journal ArticleDOI
TL;DR: In this paper, basic concepts and algorithms laid as foundations of the scheme of landing on the Martian moon Phobos (developed for the Phobos-Grunt project) are presented.
Abstract: Basic concepts and algorithms laid as foundations of the scheme of landing on the Martian moon Phobos (developed for the Phobos-Grunt project) are presented. The conditions ensuring the landing are discussed. Algorithms of onboard navigation and control are described. The equations of spacecraft motion with respect to Phobos are considered, as well as their use for correction of the spacecraft motion. The algorithm of estimation of the spacecraft’s state vector using measurements with a laser altimeter and Doppler meter of velocity and distance is presented. A system for modeling the landing with a firmware complex including a prototype of the onboard computer is described.

2 citations


Cited by
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Journal ArticleDOI
Yue Wang1, Xiaojie Wu1
TL;DR: In this article, a dynamical model was developed in the body-fixed frame of Phobos, in which the high-precision gravity field and exact physical libration of phobos, the gravity of Mars with J2, and the gravity perturbations of the Sun, Jupiter, and Earth are considered.
Abstract: A dynamical model is developed in the body-fixed frame of Phobos, in which the high-precision gravity field and exact physical libration of Phobos, the gravity of Mars with J2, and the gravity perturbations of the Sun, Jupiter, and Earth are considered. The JPL development ephemeris are applied to calculate the positions of celestial bodies. Phobos is considered as a homogeneous polyhedron with 16 037 vertices to characterize its irregular shape and the corresponding gravity field. The physical libration of Phobos is incorporated into its rotational motion by using the results in ‘Report of the IAU WGCCRE’. With the proposed model, equivalent gravity and slope on Phobos surface are calculated and analysed. The liftoff velocity is also computed and presented. Besides, the orbital environment is also investigated. Instantaneous equilibrium points in the Mars–Phobos system are computed and demonstrated, and the acceleration of a particle in the vicinity of Phobos is analysed to find out the main influencing factor in different regions. Quasi-satellite orbits and libration point orbits, which were determined in the circular restricted three-body problem model, are simulated in different dynamical models. The results applying the newly developed high-fidelity dynamical model have shown significant differences with respect to existing models, suggesting that dynamical models with higher accuracy are needed for close-range orbital activities.

8 citations

Journal ArticleDOI
TL;DR: A novel double-loop guidance and control strategy for under-actuated lunar landers in terminal landing phases is developed by using adaptive nonlinear control approach and tuning rules for designing parameters in guidance law and attitude controller are derived based on the Lyapunov analysis.

4 citations

Journal ArticleDOI
TL;DR: For the descent from the pericenter of a prelanding circumlunar orbit a comparison of three algorithms for the control of lander motion is performed.
Abstract: For the descent from the pericenter of a prelanding circumlunar orbit a comparison of three algorithms for the control of lander motion is performed. These algorithms use various combinations of terminal and programmed control in a trajectory including three parts: main braking, precision braking, and descent with constant velocity. In the first approximation, autonomous navigational measurements are taken into account and an estimate of the disturbances generated by movement of the fuel in the tanks was obtained. Estimates of the accuracy for landing placement, fuel consumption, and performance of the conditions for safe lunar landing are obtained.

3 citations

Journal ArticleDOI
01 Feb 2021
TL;DR: A novel multi-stage trajectory transfer and fixed-point landing time optimal guidance method for the lunar surface emergency rescue mission is proposed and the whole time process guidance law is obtained by establishing the allowable control set for each stage in the whole process.
Abstract: In this paper, a novel multi-stage trajectory transfer and fixed-point landing time optimal guidance method for the lunar surface emergency rescue mission is proposed. Firstly, the whole process motion and dynamics model for the lunar surface emergency rescue with four stages are established. Then, in the initial orbit transfer phase, the Lambert algorithm based on "prediction + correction" is designed for the non spherical gravitational perturbation of the moon. In the powered descent phase, the Hamiltonian function is used to design a time suboptimal explicit guidance law that can be applied in orbit in real time. Finally, aiming at the multi-stage global time optimal guidance, the whole time process guidance law is obtained by establishing the allowable control set for each stage in the whole process. The simulation results show that compared with the piecewise optimal control method, the present method has better optimization effect and shorter whole process time. It is of great significance to the possible emergency rescue mission of manned lunar exploration in the future.

1 citations