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4 Navigations from Ground to Space
(9) To provide the working environmental conditions for the command and control
staffs, and organize the comprehensive technical analysis of the spaceflight
missions, so as to take the measures in time according to the plan or decisionmaking in the case of failure.
The purpose of setting up the operation center of TT&C network is to coordinate
multiple spaceflight missions to share the same TT&C network. In the case of less
TT&C stations and missions, the operation center can be combined with the mission
command and control center.
The TT&C station is a TT&C unit that directly carries out the tracking, control,
communication and data transmission for spacecrafts. Under the organization and
command of the control center, the main tasks of the TT&C stations are: to track and
measure the orbit and attitude parameters of the spacecrafts; to receive and demodulate the telemetry information from the spacecrafts; to send the injecting commands
and data codes to the spacecrafts; to communicate and exchange data with the spacecrafts. According to the different configurations and functions, the TT&C stations
are divided into single function stations and multi-function stations. The single function stations have only one of the TT&C functions, such as tracking measurement
station, telemetry station, remote control station and space-ground communication
station. The multi-function stations have two or more TT&C functions, usually with
the typical configurations, such as the telemetry and space-ground communication
station, the tracking measurement and telemetry and remote control station, and the
integrated station with four TT&C functions.
According to the different deployment locations, the TT&C stations are divided
into ground-based station, aircraft-based station and satellite-based station, where the
ground-based station includes land-based fixed station, land-based mobile station
and tracking ship on the sea. The land-based fixed station refers to the ground
station with the fixed location on the land, which is usually equipped with largescale infrastructure facilities, and the selection of its site location required with small
shielding angle, good electromagnetic environment and convenient living condition
(such as power supply, communication, transportation and water source), as well
as considering suitable for various types of TT&C missions and observation arcsegments. The land-based mobile station is a kind of the TT&C station on board
of the vehicle, that is, usually installing the TT&C equipment on its chassis or in its
carriage, and the vehicle is driven to the designated place to perform the TT&C tasks.
The mobile stations are mainly used for temporary supplementary measurements and
covering some TT&C arc-segment gaps. It is very necessary to carry out the TT&C at
the gaps for some spaceflight keypoints, such as the braking points for the recoverable
satellites, the re-entry points for the manned spacecrafts and the arc-segments for
the manned spacecrafts flying out of the ionization blackout. The mobile stations are
usually deployed at the sites where the spaceflight missions are few frequent while
it is unnecessary to set up the long-term stations, or which are located in the remote
mountainous areas where it is not suitable to build the fixed stations. The tracking
ship is a mobile TT&C station, which can freely be deployed in the most favorable
TT&C sea area in accordance with the sub-satellite points and the requirements for
4 Navigations from Ground to Space
(9) To provide the working environmental conditions for the command and control
staffs, and organize the comprehensive technical analysis of the spaceflight
missions, so as to take the measures in time according to the plan or decisionmaking in the case of failure.
The purpose of setting up the operation center of TT&C network is to coordinate
multiple spaceflight missions to share the same TT&C network. In the case of less
TT&C stations and missions, the operation center can be combined with the mission
command and control center.
The TT&C station is a TT&C unit that directly carries out the tracking, control,
communication and data transmission for spacecrafts. Under the organization and
command of the control center, the main tasks of the TT&C stations are: to track and
measure the orbit and attitude parameters of the spacecrafts; to receive and demodulate the telemetry information from the spacecrafts; to send the injecting commands
and data codes to the spacecrafts; to communicate and exchange data with the spacecrafts. According to the different configurations and functions, the TT&C stations
are divided into single function stations and multi-function stations. The single function stations have only one of the TT&C functions, such as tracking measurement
station, telemetry station, remote control station and space-ground communication
station. The multi-function stations have two or more TT&C functions, usually with
the typical configurations, such as the telemetry and space-ground communication
station, the tracking measurement and telemetry and remote control station, and the
integrated station with four TT&C functions.
According to the different deployment locations, the TT&C stations are divided
into ground-based station, aircraft-based station and satellite-based station, where the
ground-based station includes land-based fixed station, land-based mobile station
and tracking ship on the sea. The land-based fixed station refers to the ground
station with the fixed location on the land, which is usually equipped with largescale infrastructure facilities, and the selection of its site location required with small
shielding angle, good electromagnetic environment and convenient living condition
(such as power supply, communication, transportation and water source), as well
as considering suitable for various types of TT&C missions and observation arcsegments. The land-based mobile station is a kind of the TT&C station on board
of the vehicle, that is, usually installing the TT&C equipment on its chassis or in its
carriage, and the vehicle is driven to the designated place to perform the TT&C tasks.
The mobile stations are mainly used for temporary supplementary measurements and
covering some TT&C arc-segment gaps. It is very necessary to carry out the TT&C at
the gaps for some spaceflight keypoints, such as the braking points for the recoverable
satellites, the re-entry points for the manned spacecrafts and the arc-segments for
the manned spacecrafts flying out of the ionization blackout. The mobile stations are
usually deployed at the sites where the spaceflight missions are few frequent while
it is unnecessary to set up the long-term stations, or which are located in the remote
mountainous areas where it is not suitable to build the fixed stations. The tracking
ship is a mobile TT&C station, which can freely be deployed in the most favorable
TT&C sea area in accordance with the sub-satellite points and the requirements for