80
3 System Design of Lunar Lander
for small modules, whose function were implementation of deployment and
pivoting [8].
(2) Landing cushion subsystem was a special subsystem in lunar lander. There
are four landing legs while each leg is made up of main pillar, auxiliary pillar,
foot pad, holding and release mechanism. The function of landing cushion
subsystem was: absorbing impact energy of soft landing, adapting different
lunar terrain and maintaining stable attitude after landing, providing solid
support for long-term operation on lunar surface.
(3) GNC subsystem was abbreviation of Guidance, Navigation and Control
subsystem, which was made up of star trackers, sun sensors, Inertial
Measurement Units (IMU), Central Control Unit (CCU), laser ranging
sensor, microwave ranging sensors and speedometer, laser three-dimensional
imaging sensors and etc. The function of GNC subsystem was: attitude
measurement and maintenance, orbit control, providing information of
ranging and speedometer relative to the Moon to satisfy requirements of
powered descent, autonomous navigation and control of powered descent.
(4) The bi-propellant propulsion subsystem was made up of control unit, fuel tank,
gas tank, pipe and valves, thrust for attitude control and one 7500 N throttlable
engine. Its function was to provide force required for attitude control and
powered descent of lunar lander.
(5) Thermal control subsystem was made up of innovative variable conductance
heat pipe, two phase heat loop, RHUs besides conventional heat pipe, thermal
paints and radiators. Its function was to ensure thermal management and
temperature of all instruments in whole life cycle of lunar lander.
(6) TT&C subsystem was made up of S/X/UHF band antenna, transponder, solid
amplifier, unified frequency source, data transmission modulator. Its function
was to provide radio channel between lunar lander and the ground station,
cooperate with the ground station to implement TT&C and data transmission
of lunar lander, provide radio channel between lunar lander and the lunar rover
to receive telemetry and scientific data from the lunar rover and send the data to
OBDH for processing. There are S band and X band telemetry and command
link with X band for data transmission in order to satisfy the requirement of
the ground station. There was UHF telecommunication link between lunar
lander and the lunar rover. There was also mid-gain data transmission channel
for near real time data transmission during powered descent.
(7) OBDH subsystem was an integrated synthetic electronic subsystem. It could
provide comprehensive service and management for lunar lander platform
and payloads by a centralized computer system that could process measure
and control tasks for lunar lander. It could implement orbital operation
management and synthetic information processing by a kernel data system
for lunar lander. It could manage and control every task with high efficiency and reliability, monitor health status and coordinate different tasks
for lunar lander. It could manage and process the data of payloads. It could
process and share information of lunar lander centrally. It was made up of
3 System Design of Lunar Lander
for small modules, whose function were implementation of deployment and
pivoting [8].
(2) Landing cushion subsystem was a special subsystem in lunar lander. There
are four landing legs while each leg is made up of main pillar, auxiliary pillar,
foot pad, holding and release mechanism. The function of landing cushion
subsystem was: absorbing impact energy of soft landing, adapting different
lunar terrain and maintaining stable attitude after landing, providing solid
support for long-term operation on lunar surface.
(3) GNC subsystem was abbreviation of Guidance, Navigation and Control
subsystem, which was made up of star trackers, sun sensors, Inertial
Measurement Units (IMU), Central Control Unit (CCU), laser ranging
sensor, microwave ranging sensors and speedometer, laser three-dimensional
imaging sensors and etc. The function of GNC subsystem was: attitude
measurement and maintenance, orbit control, providing information of
ranging and speedometer relative to the Moon to satisfy requirements of
powered descent, autonomous navigation and control of powered descent.
(4) The bi-propellant propulsion subsystem was made up of control unit, fuel tank,
gas tank, pipe and valves, thrust for attitude control and one 7500 N throttlable
engine. Its function was to provide force required for attitude control and
powered descent of lunar lander.
(5) Thermal control subsystem was made up of innovative variable conductance
heat pipe, two phase heat loop, RHUs besides conventional heat pipe, thermal
paints and radiators. Its function was to ensure thermal management and
temperature of all instruments in whole life cycle of lunar lander.
(6) TT&C subsystem was made up of S/X/UHF band antenna, transponder, solid
amplifier, unified frequency source, data transmission modulator. Its function
was to provide radio channel between lunar lander and the ground station,
cooperate with the ground station to implement TT&C and data transmission
of lunar lander, provide radio channel between lunar lander and the lunar rover
to receive telemetry and scientific data from the lunar rover and send the data to
OBDH for processing. There are S band and X band telemetry and command
link with X band for data transmission in order to satisfy the requirement of
the ground station. There was UHF telecommunication link between lunar
lander and the lunar rover. There was also mid-gain data transmission channel
for near real time data transmission during powered descent.
(7) OBDH subsystem was an integrated synthetic electronic subsystem. It could
provide comprehensive service and management for lunar lander platform
and payloads by a centralized computer system that could process measure
and control tasks for lunar lander. It could implement orbital operation
management and synthetic information processing by a kernel data system
for lunar lander. It could manage and control every task with high efficiency and reliability, monitor health status and coordinate different tasks
for lunar lander. It could manage and process the data of payloads. It could
process and share information of lunar lander centrally. It was made up of