THE CONCEPT OF CREATING A HARDWARE AND SOFTWARE COMPLEX FOR SPACECRAFT CONTROL

THE CONCEPT OF CREATING A HARDWARE AND SOFTWARE COMPLEX FOR SPACECRAFT CONTROL

Maxim Kutsev

applikant to PHD, Republican Center for Space Communication,

Kazakhstan, Astana

 

Spacecraft Management and control is a complex technological process consisting of interrelated and time-distributed control operations aimed at ensuring that the spacecraft performs tasks in accordance with its purpose. To perform these tasks, a hardware and software complex is used, consisting of a Mission Control Center and a Communication monitoring system.

 

1. Mission Control Center

1.1 The hardware and software complex of the Mission Control Center (MCC) of the spacecraft (SC) is designed for:

- continuous management and control of the spacecraft;

- control of the orbital position and keeping the spacecraft in a given orbital position with the necessary accuracy;

- planning the operation of on-board equipment and equipment of ground management and control stations of the spacecraft (GS) for the operation of the spacecraft. Based on its purpose, MCC performs the following functions:

- calculation and formation of spacecraft management programs;

- preparation of special data files for their bookmark on the spacecraft;

- conducting a control session with a satellite, including working out both pre-prepared control programs and control programs or commands entered by the operator in real time;

- registration and processing of information messages received from GS and spacecraft equipment, monitoring the implementation of the control program for incoming telemetry information (TI);

- receiving, processing, displaying and analyzing information about the results of GS work;

- TI reception;

- automated monitoring of the state of the spacecraft by TI, with their display in graphical form, with color and sound signaling of the output of any parameter beyond the tolerance limits;

- display of information about the satellite status, configuration of its systems and ground stations by visual diagrams;

- remote control and GS status monitoring;

- logging of actions of the operators of the spacecraft;

- storing the results of management and control sessions during the active existence of the spacecraft;

- protection of software for direct satellite control from unauthorized actions;

- operational interaction with GS;

- planning of spacecraft orbital position measurement sessions;

- reception, pre-processing and evaluation of orbital position measurement sessions;

- calculation of spacecraft motion parameters;

- a posteriori assessment of the accuracy of determining and predicting satellite motion parameters;

- calculation of parameters for correction of spacecraft retention in a given area;

- calculation of the flight task for the functioning of the onboard equipment of the spacecraft;

- TI monitoring of the status of on-board equipment and analysis of the performance of the flight task;

- calculation of ballistic information to ensure the normal operation of the spacecraft (prediction of motion parameters, calculation of shadow areas from the Earth and the Moon, etc.);

- calculation of collocations with other spacecraft of the orbital grouping;

- calculation of the necessary ballistic information for the analysis of emergency situations.

1.2 Composition and technical characteristics of the MCC

The architectural construction of the MCC is represented by a single local network, which has the following advantages:

- the topology of the MCC construction and related administration procedures, access rights control and operator authority are simplified by using a domain network structure with a single primary domain controller (and a secondary domain controller reserving it);

- the reliability of the MCC increases due to the use of a single data warehouse – a central database (DB) hosted on a fault-tolerant server of cluster execution, as well as the use of a centralized pool of operator workstations (OW) without reconfiguring the structure of the local network;

- the size of routing tables is reduced, which provides traffic during the interaction of the main and backup MCC.

In the MCC, organizational and functional components are allocated, specialized in groups of functionally similar tasks, interacting through a single computer network and located in the premises of the MCC. Taking into account the existing experience in creating such systems, it is proposed to allocate the following four organizational and functional elements in the MCC:

- ground control and monitoring station of the spacecraft;

- communication and data transmission networks;

- management, control and training software;

- database;

- communication monitoring system.

As shown in Figure 1

1.2.1 Ground station

The ground station solves the tasks of ensuring interaction between the MCC and the spacecraft. The operating mode is round–the-clock.

 

Figure 1. Organizational and functional components Mission control center

 

1.2.2 Communication and data transmission environment.

The communication and data transmission environment provides information exchange between the components of the MCC, regardless of the territorial location. The operating mode is round–the-clock.

1.2.3 Management, control and training software

In management and control, the tasks of direct control of the satellite and GS are solved. The mode of operation is daytime, round–the-clock.

1.2.4 Database

The database solves the tasks of storing operational and long-term storage of data obtained during quality management and control.

1.2.5 Communication monitoring system

The Communication monitoring System (CMS) solves the tasks of monitoring the frequency and energy parameters of ground station signals transmitted through spacecraft transponders.

1.3 MCC hardware

The MCC hardware includes:

- computer equipment;

- communication equipment of the local network;

- display tools;

- office equipment (printers, scanners, copiers, etc.);

- voice, fax and telephone communication, as well as e-mail.

1.4 MCC Software

The MCC software includes:

- general system software, including operating systems, databases and antivirus programs, administration programs;

- special software;

The special software of the MCC includes:

- management and control software;

- software for ballistic calculations;

- spacecraft mission planning software;

- database management software.

The general structure of the MCC and the composition of its software components are shown in Figure 2.

1.4.1 Management and control software

The management and control software solves the tasks of direct control of the spacecraft and GS, provides control of the spacecraft payload, provides continuous reception, processing, analysis, documentation and archiving of TI, continuous monitoring of the technical condition of the spacecraft according to TI data. Performs reception, operational assessment and analysis of TI, its display, documentation and archiving, collection and accumulation of statistical information on the management procedures carried out, as well as subsequent processing of accumulated information in the form of various reporting forms.

 

Figure 2. Mission control center software structure

 

1.4.2 Mission planning software (MP).

The flight task planning program of the spacecraft calculates the formation, registration, documentation and issuance of technological data, commands and control programs of the spacecraft and PI. Mission planning is used both in the preparation of satellite control sessions and during their conduct.

1.4.3 Ballistic calculations software.

The Ballistic Calculations software (BC) provides a solution to all ballistic problems of keeping the spacecraft in a given orbital position with the necessary accuracy and collocation with other spacecraft.

1.4.4 Adaptation Server Program

The Adaptation Server (AS) software provides information interaction between the ground control station of the spacecraft and the software Management and control of the workstations of the spacecraft operators.

1.4.5 Database administration software.

The database administration software solves the tasks of storing operational and long-term storage of data obtained during the management and control of the spacecraft.

The structural and functional scheme of the MCC hardware and software complex is shown in Figure 3

 

Figure 3. Structural and functional scheme of the MCC hardware and software complex

 

1.5 The concept of building a backup MCC

The backup MCC should be geographically removed from the main MCC, in order to provide independent power supply, means of access to communications.

The backup MCC has the same functionality and has the same organizational and technical structure as the main MCC.

The current state of the backup MCC database is provided by replication (copying) of the database tables of the main MCC.

The structural and functional scheme of building a backup MCC with the main MCC is shown in Figure 4.

2. Ground control and monitoring station of the spacecraft (Ground Station, GS)

GS is designed to provide control of the spacecraft.

GS performs the following main tasks:

- reception from the MCC via public data transmission networks of technological, command and program information, target designation for GS antenna systems;

- search for the spacecraft, entering into communication and automatic tracking of the spacecraft;

- transmission of the mission plan and control commands to the satellite;

 

Figure  4. Structural and functional scheme of building a backup MCC with the main MCC

 

- measurement of the spacecraft's orbital position, preliminary processing of information and its delivery to the MCC;

- reception from the TI satellite, its pre-processing and transmission to the MCC to public data transmission networks;

- formation and binding of the local GS time scale to world time;

- generation of reports on the condition of GS equipment and the results of passing commands and flight tasks on the spacecraft and transmitting this information to the MCC;

- display, documentation and archiving of all types of information.

The functional (general) scheme of GS is shown in Figure 5.

 

Figure 5. Functional ground station scheme

 

3. Communication monitoring system

3.1 Solved tasks

CMS are designed for:

- conducting orbital tests of spacecraft transponders, in the entire operating frequency range;

- monitoring of spacecraft transponders in the entire operating frequency range of spacecraft transponders;

- testing of tenants' earth stations for their admission to work in spacecraft transponders;

- analysis of carriers of all spacecraft transponders and output of results;

- monitoring of the interference situation in transponders;

- reception, processing and documentation of measurement results;

3.2 The concept of creating SMS

The concept of creating SMS involves two stages:

1 - Conducting orbital tests of the spacecraft payload (IOT).

2 - Monitoring of communication channels of the spacecraft payload.

At the first stage of operation, the CMS spacecraft is used exclusively for IOT purposes without monitoring functions.

At the second stage, CMS is used to monitor communication channels.

The functional (general) scheme of the CMS is shown in Figure 6

 

Figure 6. Functional communication monitoring system scheme

 

4. Communication and data network

Communication and data network provides transmission:

1) in the direction of the MCC - GS (in this case, the MCC means any center, including the main, backup and external):

- target designations for pointing antennas;

- technological data of the satellite;

- commands to control the operation of GS equipment;

- flight mission and spacecraft control commands;

2) in the direction of GS - MCC:

- TI;

- reports on the execution of communication sessions;

- confirmation of receipt of the mission plan by the spacecraft;

- results of ballistic measurements;

Global networks are used for information interaction of objects that are remote over long distances, to which MCC elements belong.