Introduction to the hottest American space shuttle

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Spaceshuttle Introduction (2)


the software stored and executed by the space shuttle orbiter computer is the most complex program in space flight, which controls all aspects and stages of space shuttle activities

software is divided into system software and application software. Each program can be written to be executed by a single computer or multiple computers. The execution mode of multiple computers is designed to perform the work of key flight stages such as launch, ascent, re-entry and flight termination

the system software is composed of computer control program, user interface program and system control program, which fully comply with the requirements of gb21238 (2) 007 glass fiber reinforced plastic sanding pipe gb/t9647 (2) 003 determination of ring stiffness of thermoplastic pipe. The flight computer operating program is responsible for controlling processors, monitoring keyboard system parameters, allocating computer resources, interrupting programs in order, providing high priority activities, and updating computer memory. The user interface program provides instructions for handling the commands and requests of maintenance personnel. The system control program is used to initialize the computer and arrange multiple computer control modes in key flight segments

there are four kinds of application software: special software program, system management program, payload processing program and space shuttle detection program. The special software program is used to guide, navigate and control the space shuttle in the stages of launch, ascent, orbital maneuver, re-entry and landing. The system management program is used to detect each subsystem of the space shuttle, check whether the crew's display and controller work normally, and update the state vector of the inertial measurement unit. In addition, this group of programs also includes instructions for binding the memory of the main engine computer and instructions for detecting and measuring the system. The payload handler is a set of instructions to control and monitor the payload, and what is the distance between the markings? Most of the distances given by different standards have a certain difference, which can be modified according to the nature of the payload. The space shuttle inspection program is used for maintenance data management, performance monitoring and special processing

the program is written in hal/s (high-order combinatorial language/space shuttle) language. Programs are stored in memory groups according to function groups. When necessary, the program can be extracted from the mass memory, and the memory can be recombined according to the operating program of the required function. The highest level program of application software is operation program (OPS). Each group of OPS is a group of special software used to complete phase oriented tasks. Ops can also be divided into several main modes, and each mode represents a part of OPS task segment. For example, OPSL can be divided into six main modes. Ops function software will display some data formats and configurations through CRT, but they cannot be changed by astronauts, and can only provide information. Ops expert function software can display on CRT and allow astronauts to input information with keyboard, operate and monitor the work of the space shuttle

data communication

inter machine communication

4 inter machine buses are cross connected to 4 computers. Each computer can access the data status received or transmitted by other computers to check whether the calculation results of the four computers are consistent. Each computer is equipped with the same software, and the four buses are connected with a computer working in command mode. For this bus, the other three computers work in listening mode. Each computer has the ability to receive data from the other three computers, transmit data to other computers, request data, and complete the tasks required by the redundant unit

4 inter aircraft buses are not connected with any other subsystem of the space shuttle

communication between computers and subsystems

c data communication between guidance, navigation and control systems 8 GPC flight critical buses are connected to 4 computers in 2 groups. The FC-1 ~ FC-4 bus transmits the commands and data of the pilot control system, display device and front guidance, navigation and control (gnlc) system at the pilot level, and the FC-5 ~ fc-8 bus transmits the data and commands of the rear GN LC system. One bus in the group is assigned to a computer working in command mode. The computer working in command mode sends data requests and commands to the relevant systems of the space shuttle through its special bus, and the remaining three buses are allocated to the other three computers working in listening mode to listen to the computer information working in command mode

gn C system components are connected with each MDM and flight critical bus and have the following functions: through them, each computer sends commands and requests data to GN C system components

the redundancy of GN C system components varies between 2 and 4. Redundancy management software can select a group of data from redundant components that can be used for flight control, guidance and navigation; It can also find out the data exceeding the tolerance, find out the faulty components, and notify the flight personnel and data collection software of the fault. For example, for four redundant components, the software selects and releases three components and takes the middle value, and the fourth component is standby. When one of the three components fails, the fourth component can be used. If one of the remaining three pieces fails, reduce the mode to 2 and take the average value. The mode will be reduced to 1 when there is another failure in 2 pieces, and only the data it receives can be transmitted

during non critical orbit flight, only 1-2 computers are used for GN C work, and the other several are used for payload operation and system management, and can also be stopped and reserved for standby

c data communication with the main engine three main engine interfaces transmit computer commands and data of the main engine controller. Engine ignition, swing, throttle, shutdown and other functions are controlled by the main engine controller with the input signal of the guidance equation calculated by GPC

The data communication GPC between the

c and the main event controller (MEC) communicates with two MECs through the flight critical bus. The two MECs controlled by GPC provide initiating explosive device insurance/release signal, initiating explosive device ignition signal and separation signal of orbiter/outer tank, outer tank/solid booster

The data communication between

c and payload is transmitted by two payload data buses. The payload data interlaced scanner centralizes the payload data into the electronic parts of the orbiter and then sends it to the ground telemetry device

the data communication between GPC and ground equipment and solid booster is realized by two ground interface buses. The receiving part of the amplifier is isolated by the data bus of the interface device, the low-level encoded signal is found, the noise is removed, and the signal is decoded into standard digital data. The transmission part of the amplifier re encodes the data and transmits it under low noise conditions with full amplitude

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