Abstract: The subject of the research is an optical direction finder for the navigation and guiding a space probe. The usage of the optical correlation computing device is determined by the necessity to reduce the load to a space probe on-board computer system. The paper describes especially the optical correlation computing devices for building the correlation-extremal direction finders. The principle optical schemes of this class of optical devices are described. The method of mathematical modeling is used for building and analyzing the optical scheme of the proposed optical correlation computing devices. Both advantages and disadvantages of the existed optical schemes are noted. The requirements to parameters of the special on-board optical correlation computing device for the direction finding are proposed. It is shown that the optical device potentially can be used for navigation and guiding a space probe in the process of the landing on a small body of the solar system.

Abstract: In this article the authors focus on the issues that relate to using the promising technique of optical correlation for onboard guidance and landing a space probe on a surface of a solar system small body. The authors use the ability of optical systems to perform the Fourier transformation which allows to construct optical-electronic devices of high-speed and high-efficiency computing systems. Distribution of illumination (energy) inplane or through the lens of the entrance pupil is an input data flow for an optical computing system that has been constructed on the basis of the aforesaid principle. In a general way, this information will function as a reference standard tranmission according to two (x, y) coordinates. To analyze the aforesaid aspects, the authors of the article have used mathematical analysis methods, in particular, integral calculus for creating a mathematical model of an optical correlation bearing finder with a revolving the reference standard. The authors suggest to modulate an optical signal going through a transparent reference standard both upon the amplitude and phase. The advantage of the method is a superspeed of information processing that is restricted by the light velocity and happens almost at instance taking into account small sizes of devices. The authors give a theoretical justification of the efficiency of the optical polar correlation method. The authors demonstrate that in order to neutralize the reference standard when guiding and landing a space probe it is better to use a revolving of a reference image. The authors also analyze the method of revolving of a reference image to find the function extremum of the correlation signal and neutralizing the reference standard.

Abstract: The basic requirements for the on-board complex of the spacecraft for purposes of guidance and landing on small bodies of the solar system are formulated in the work. The main tasks of the landing and landing vehicles are braking and approaching the surface of the celestial body, landing, working on its surface, possibly taking off from the surface to deliver the returned vehicle to the ground. Providing high requirements to the accuracy and reliability of the on-board guidance and landing system, an actual solution is proposed. Using the traditional approach to the modeling of processes and systems, a functional model of the onboard guidance and landing system in IDEF0 notation was created. In the process of creating a functional model, the main processes performed by the complex during descent from orbit and landing are described. As a result of the work, a description of the procedures performed by the multifunctional on-board guidance and landing system of the spacecraft has been obtained. An applied functional model of the "to-be" level was constructed, based on the use of an integrated approach. The proposed integrated approach is focused on the sharing of data from all on-board devices, both basic and backup information. This approach allows to increase the accuracy and reliability of the landing procedure.