12.3 Characteristics of System Integration and Assembly
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be assembled for the lunar lander. During assembly process, the operating environment should be controlled and the safety precautions such as anti-static and collision
prevention should be developed.
(2) Assembly of instruments with professional test requirements. There were over
20 sensors on the lunar lander, whose accuracy should be ensured in system assembly.
At the same time, there were complex pipelines with thousands of solder joints and
nearly 100 screw contacts, whose leakage rate requirements should be satisfied. In
addition, the requirement for mass center of the lunar lander should be satisfied.
Therefore, in the assembly of hardware with special requirements, it was necessary
to ensure the polarity of hardware assembly, control foreign object, and conduct
crucial confirmation in the key assembly steps.
(3) Assembly and test of moving parts. There were more than 10 sets of mechanisms on the lunar lander. The assembly quality of mechanism was directly involved
the deployment performance of the mechanism. In assembly process of mechanisms,
it was necessary to strictly control the interference inspection of the moving parts,
including cables, multi-layers, ground test tools, and conduct ground verification
tests.
(4) Assembly of radioisotope instruments. There were 4 sets (sets) of instrument
with radioactive isotopes on the lunar lander. The assembly process flow must be
carefully designed in order to ensure the operator’s safety in the process.
(5) Assembly requirements for ground support equipment. Various special tests
should be conducted for the Chang’E-3 lunar lander. In order to implement the tests,
various types of technological equipment, such as flip trolley, flip hanger and impact
hanger, should be developed. In the design of each ground support equipment for
test, the assembly process should be determined, as well as protection for onboard
instruments during assembly.
12.3.2 Features of Assembly Technology
The features of system integration and assembly technology for the lunar lander were
as follows.
(1) There were a lot of engines/thrusters, and the piping system was complex,
which made the assembly difficult. Because the flight profile of the Chang’E-3 lunar
lander was complex, there were more engines or thrusters and complex pipeline
on the lunar lander. Especially during the powered descent phase, the large engine
should fire for a long time, which led new requirements of large engine assembly
and thermal protection. There were 29 engine/thrusters including one orbit control
engine and 28 attitude control thrusters on the Chang’E-3 lunar lander. Because of
these engine and thrusters, there were a lot of propulsion lines and the configuration
was complex, as well as large volume of propellant tanks, which caused that there
were many key assembly steps. At the same time, the 7500 N throttling engine was
applied for the first time in China, and new issues were faced with in assembly,
measurement and precision adjustment of the engine.
407
be assembled for the lunar lander. During assembly process, the operating environment should be controlled and the safety precautions such as anti-static and collision
prevention should be developed.
(2) Assembly of instruments with professional test requirements. There were over
20 sensors on the lunar lander, whose accuracy should be ensured in system assembly.
At the same time, there were complex pipelines with thousands of solder joints and
nearly 100 screw contacts, whose leakage rate requirements should be satisfied. In
addition, the requirement for mass center of the lunar lander should be satisfied.
Therefore, in the assembly of hardware with special requirements, it was necessary
to ensure the polarity of hardware assembly, control foreign object, and conduct
crucial confirmation in the key assembly steps.
(3) Assembly and test of moving parts. There were more than 10 sets of mechanisms on the lunar lander. The assembly quality of mechanism was directly involved
the deployment performance of the mechanism. In assembly process of mechanisms,
it was necessary to strictly control the interference inspection of the moving parts,
including cables, multi-layers, ground test tools, and conduct ground verification
tests.
(4) Assembly of radioisotope instruments. There were 4 sets (sets) of instrument
with radioactive isotopes on the lunar lander. The assembly process flow must be
carefully designed in order to ensure the operator’s safety in the process.
(5) Assembly requirements for ground support equipment. Various special tests
should be conducted for the Chang’E-3 lunar lander. In order to implement the tests,
various types of technological equipment, such as flip trolley, flip hanger and impact
hanger, should be developed. In the design of each ground support equipment for
test, the assembly process should be determined, as well as protection for onboard
instruments during assembly.
12.3.2 Features of Assembly Technology
The features of system integration and assembly technology for the lunar lander were
as follows.
(1) There were a lot of engines/thrusters, and the piping system was complex,
which made the assembly difficult. Because the flight profile of the Chang’E-3 lunar
lander was complex, there were more engines or thrusters and complex pipeline
on the lunar lander. Especially during the powered descent phase, the large engine
should fire for a long time, which led new requirements of large engine assembly
and thermal protection. There were 29 engine/thrusters including one orbit control
engine and 28 attitude control thrusters on the Chang’E-3 lunar lander. Because of
these engine and thrusters, there were a lot of propulsion lines and the configuration
was complex, as well as large volume of propellant tanks, which caused that there
were many key assembly steps. At the same time, the 7500 N throttling engine was
applied for the first time in China, and new issues were faced with in assembly,
measurement and precision adjustment of the engine.