3.5 System Components and Specifications
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System Management Unit (SMU) and Data Interface Unit (DIU) whose integrated function was to provide management of onboard uplink and downlink data, thermal control, mechanism control, power supply distribution and
autonomous routine management.
(8) Power supply subsystem was made up of solar panels, battery and power
supply controller. Its function was to be responsible for first-hand power
supply acquirement, modulation and supply.
(9) General circuit subsystem was made up of cable, connectors and separation
switchers. Its function was to transmit electricity in lunar lander.
(10) Payloads subsystem was made up of four scientific instruments including
descent camera, lunar terrain camera, lunar optical telescope and ultra-violet
camera to obtain scientific data.
(11) Engineering parameters measure subsystem was made up of monitor camera,
lunar dust detector for accumulating engineering data, monitoring implementation of different tasks and acquiring further data of lunar environment.
3.5.2 Major System Specifications
The major system specifications of the CE-3 lunar lander are listed in Table 3.3.
3.5.3 Propellant Budget
For lunar lander, the propellant for the powered descent was the emphasis in propellant budget besides propellant for orbit control, attitude control, bias of mixture ratio,
expulsion efficiency of propellant tank, propellant remaining in pipe and etc. as for
conventional spacecraft.
For the CE-3 lunar lander, the amount of propellant consumption varied in ±30 kg
because of different lunar terrain along powered descent flight path in different launch
windows and error of measurement and control. So requirements of different launch
windows should be considered for propellant budget.
The design of propellant budget margin should be traded off for lunar lander.
For conventional spacecraft in orbit, the margin of propellant was relative large
to maintain strong capability for orbit control and attitude correction so that all
conventional or unexpected requirements could be satisfied. For the lunar lander,
it was helpful to keep large propellant margin before powered descent in order to
improve safety of soft landing in case of possible failure during powered descent.
But the mass of propellant required to make the propellant margin be landed on lunar
surface was two times of the mass of propellant margin. After soft landing, the mass of
propellant margin became useless ‘dumb mass’. The remaining of propellant should
be depleted to avoid propellant leakage under extreme high and low temperature on
81
System Management Unit (SMU) and Data Interface Unit (DIU) whose integrated function was to provide management of onboard uplink and downlink data, thermal control, mechanism control, power supply distribution and
autonomous routine management.
(8) Power supply subsystem was made up of solar panels, battery and power
supply controller. Its function was to be responsible for first-hand power
supply acquirement, modulation and supply.
(9) General circuit subsystem was made up of cable, connectors and separation
switchers. Its function was to transmit electricity in lunar lander.
(10) Payloads subsystem was made up of four scientific instruments including
descent camera, lunar terrain camera, lunar optical telescope and ultra-violet
camera to obtain scientific data.
(11) Engineering parameters measure subsystem was made up of monitor camera,
lunar dust detector for accumulating engineering data, monitoring implementation of different tasks and acquiring further data of lunar environment.
3.5.2 Major System Specifications
The major system specifications of the CE-3 lunar lander are listed in Table 3.3.
3.5.3 Propellant Budget
For lunar lander, the propellant for the powered descent was the emphasis in propellant budget besides propellant for orbit control, attitude control, bias of mixture ratio,
expulsion efficiency of propellant tank, propellant remaining in pipe and etc. as for
conventional spacecraft.
For the CE-3 lunar lander, the amount of propellant consumption varied in ±30 kg
because of different lunar terrain along powered descent flight path in different launch
windows and error of measurement and control. So requirements of different launch
windows should be considered for propellant budget.
The design of propellant budget margin should be traded off for lunar lander.
For conventional spacecraft in orbit, the margin of propellant was relative large
to maintain strong capability for orbit control and attitude correction so that all
conventional or unexpected requirements could be satisfied. For the lunar lander,
it was helpful to keep large propellant margin before powered descent in order to
improve safety of soft landing in case of possible failure during powered descent.
But the mass of propellant required to make the propellant margin be landed on lunar
surface was two times of the mass of propellant margin. After soft landing, the mass of
propellant margin became useless ‘dumb mass’. The remaining of propellant should
be depleted to avoid propellant leakage under extreme high and low temperature on