Chapter 10
TT&C and Telecommunication
Technology of Lunar Lander
10.1 Introduction
Radio technology is the main approach to establish telecommunication between
spacecraft and ground station. According to its functions, space radio technology
can be classified into four types: tracking, telemetry, telecommand and telecommunication, while Telemetry, Tracking and teleCommand are called TT&C in China [1].
The tracking is the real time positioning of spacecraft and measurement of velocity
and orientation by automatic tracking of ground station antenna aiming at spacecraft.
Telemetry is to transform all kinds of measured physical parameters on spacecraft into
electrical signals, which are transmitted to ground station by radio wave to provide
all working status and data of on orbit spacecraft after reception and demodulation.
The telecommand is to send the control information on the ground (for spacecraft
control) in the form of electrical signal which is modulated and transmitted on radio
carrier to spacecraft. After received and demodulated, the radio signal is processed by
relative subsystems of spacecraft to control spacecraft by ground requirements. The
telecommunication is to transmit the information acquired from measuring instruments, observation instruments and instruments that collects and forwards all kinds
of information to the ground [1].
The TT&C and Telecommunication subsystem of the lunar lander was used to
perform the information transmission between lander and ground or between landers
during mission, which also played an important role in orbit determination. The
functions of onboard TT&C and Telecommunication systems included: receiving
and demodulating telecommand information transmitted by ground station to provide
OBDH subsystem for further processing; modulating and transmitting engineering
telemetry signals from OBDH subsystem; receiving, demodulating and forwarding
ranging baseband signals in downlink carrier phase modulation; cooperation with
ground station for precise orbit determination in downlink carrier modulation beacon;
transmitting scientific payload data to ground station; telecommunicating with other
landers, and etc.
© National Defense Industry Press and Springer Nature Singapore Pte Ltd. 2021
D.-Y. Yu et al., Technology of Lunar Soft Lander, Space Technology Library 38,
https://doi.org/10.1007/978-981-15-6580-9_10
333
TT&C and Telecommunication
Technology of Lunar Lander
10.1 Introduction
Radio technology is the main approach to establish telecommunication between
spacecraft and ground station. According to its functions, space radio technology
can be classified into four types: tracking, telemetry, telecommand and telecommunication, while Telemetry, Tracking and teleCommand are called TT&C in China [1].
The tracking is the real time positioning of spacecraft and measurement of velocity
and orientation by automatic tracking of ground station antenna aiming at spacecraft.
Telemetry is to transform all kinds of measured physical parameters on spacecraft into
electrical signals, which are transmitted to ground station by radio wave to provide
all working status and data of on orbit spacecraft after reception and demodulation.
The telecommand is to send the control information on the ground (for spacecraft
control) in the form of electrical signal which is modulated and transmitted on radio
carrier to spacecraft. After received and demodulated, the radio signal is processed by
relative subsystems of spacecraft to control spacecraft by ground requirements. The
telecommunication is to transmit the information acquired from measuring instruments, observation instruments and instruments that collects and forwards all kinds
of information to the ground [1].
The TT&C and Telecommunication subsystem of the lunar lander was used to
perform the information transmission between lander and ground or between landers
during mission, which also played an important role in orbit determination. The
functions of onboard TT&C and Telecommunication systems included: receiving
and demodulating telecommand information transmitted by ground station to provide
OBDH subsystem for further processing; modulating and transmitting engineering
telemetry signals from OBDH subsystem; receiving, demodulating and forwarding
ranging baseband signals in downlink carrier phase modulation; cooperation with
ground station for precise orbit determination in downlink carrier modulation beacon;
transmitting scientific payload data to ground station; telecommunicating with other
landers, and etc.
© National Defense Industry Press and Springer Nature Singapore Pte Ltd. 2021
D.-Y. Yu et al., Technology of Lunar Soft Lander, Space Technology Library 38,
https://doi.org/10.1007/978-981-15-6580-9_10
333