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12 Integration and Assembly Technology of Lunar Lander
cable, as well as movement margin of the cable to ensure smooth deployment of the
solar panel. General, verification tests on deployment and folding of the solar panel
on ground is necessary, as well as the cable interference and movement margin.
1. Assembly of Landing Gear Mechanism
The landing gear mechanism was one of the most crucial equipment of the lunar
lander. There were four landing legs and landing buffer on the landing leg to ensure
safe landing of the lunar lander.
The assembly of the lander gear mechanism included assembly of mechanical
interface and electrical interface. Four landing legs were assembly respectively. There
were primary strut, multi-function secondary strut and single function secondary
strut on each landing leg. The mechanical assembly of the lander gear mechanism
was relatively simple, where the main strut was connected to the main structure by
special bolts, and the secondary struts were connected by bolts with the bottom plate
of the lunar lander. The challenge in assembly of the landing gear mechanism was
the implementation of the assembly of the cable. At first, the margin of the cable
should be controlled to ensure that the landing gears were not interfered during
deployment and landing. Secondly, the exposed cable should be thermally protected
to avoid damage of high temperature cause by engine firing. After process design,
strict control of the cable margin was implemented and special stainless-steel wire
was applied to ensure the fixed strength of the cable, as well as adaptability to high
temperature environment caused by engine firing.
12.5.6 Assembly of Thermal Control Unit
The lunar lander would experience extremely cold lunar night at −180°C and
extremely hot lunar day at 120°C. Therefore, the requirement for thermal control
was higher and thermal control design was more complex for the lunar lander, which
resulted in strict requirement for assembly of thermal control units. Generally, there
were assembly of multi-layer heat-insulation material coating, heat pipe, electric
heater and temperature sensor in assembly of thermal control units.
1. Manufacture and Assembly of Low Temperature Multilayer Insulation Components
The material of low temperature multilayer insulation is generally formed by alternately stacking of high-emissivity reflective layer and low thermal conductivity layer,
which can form a very high thermal resistance to radiative heat flow. Because of its
good thermal insulation performance, it is a general passive thermal control method.
In order to adapt to the harsh environment with high and low temperature on lunar
surface and reduce spacecraft mass, the manufacture and assembly of low temperature multilayer insulation components should be planned, elaborately assembled and
managed. There were more than ten types of low temperature multilayer insulation
components on the Chang’E-3 lunar lander, including insulation on surfaces such as
12 Integration and Assembly Technology of Lunar Lander
cable, as well as movement margin of the cable to ensure smooth deployment of the
solar panel. General, verification tests on deployment and folding of the solar panel
on ground is necessary, as well as the cable interference and movement margin.
1. Assembly of Landing Gear Mechanism
The landing gear mechanism was one of the most crucial equipment of the lunar
lander. There were four landing legs and landing buffer on the landing leg to ensure
safe landing of the lunar lander.
The assembly of the lander gear mechanism included assembly of mechanical
interface and electrical interface. Four landing legs were assembly respectively. There
were primary strut, multi-function secondary strut and single function secondary
strut on each landing leg. The mechanical assembly of the lander gear mechanism
was relatively simple, where the main strut was connected to the main structure by
special bolts, and the secondary struts were connected by bolts with the bottom plate
of the lunar lander. The challenge in assembly of the landing gear mechanism was
the implementation of the assembly of the cable. At first, the margin of the cable
should be controlled to ensure that the landing gears were not interfered during
deployment and landing. Secondly, the exposed cable should be thermally protected
to avoid damage of high temperature cause by engine firing. After process design,
strict control of the cable margin was implemented and special stainless-steel wire
was applied to ensure the fixed strength of the cable, as well as adaptability to high
temperature environment caused by engine firing.
12.5.6 Assembly of Thermal Control Unit
The lunar lander would experience extremely cold lunar night at −180°C and
extremely hot lunar day at 120°C. Therefore, the requirement for thermal control
was higher and thermal control design was more complex for the lunar lander, which
resulted in strict requirement for assembly of thermal control units. Generally, there
were assembly of multi-layer heat-insulation material coating, heat pipe, electric
heater and temperature sensor in assembly of thermal control units.
1. Manufacture and Assembly of Low Temperature Multilayer Insulation Components
The material of low temperature multilayer insulation is generally formed by alternately stacking of high-emissivity reflective layer and low thermal conductivity layer,
which can form a very high thermal resistance to radiative heat flow. Because of its
good thermal insulation performance, it is a general passive thermal control method.
In order to adapt to the harsh environment with high and low temperature on lunar
surface and reduce spacecraft mass, the manufacture and assembly of low temperature multilayer insulation components should be planned, elaborately assembled and
managed. There were more than ten types of low temperature multilayer insulation
components on the Chang’E-3 lunar lander, including insulation on surfaces such as