4.4 Mechanism Design and Verification of Lunar Lander
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(2) Hold Down and Release Mechanism: To fold sun panels and hold down to
increase strength and rigidity of solar panels to prevent solar panels from being
damaged by the load during launch.
(3) Rotating hinge: For connection of solar panels substrate and lander structure, and to provide support for the single-degree-of-freedom rotation of the
substrate relative to lander structure.
(4) Drive assembly: To provide driving torque for solar panels deployment and
folding, and provide position holding torque for solar panels in specific
position.
(5) Safety limiter. It was used to limit the rotation of solar panels substrate
in landing phase, and improve structural strength and rigidity of solar
panels substrate to avoid damage of solar panels substrate and other related
components (such as rotating hinge) under the landing impact load.
The operation modes of solar panel mechanism are listed as follows for the Chang’E-3
lunar lander:
(1) The solar panels were held down on the top plate of lander structure by Hold
Down and Release Mechanism to withstand load during launch.
(2) After orbit injection, the Hold Down and Release Mechanism was unlocked
and the solar panels were released.
(3) In orbital flight, the sun panels were deployed and oriented toward the Sun. In
order to withstand load at the ignition and stop of the 7500 N engine of the
lunar lander and avoid the influence of engine plume on solar panels, the solar
panels were folded before the main engine ignition and deployed again after
the engine stop. According to the flight procedure, the solar panels should be
folded and unfolded more than once in orbit.
(4) Before powered descent and soft-landing, solar panels were folded to ensure
that it could withstand landing impact load. Then the safety limiter was powered
on to constrain solar panels to improve the strength and stiffness of solar panels
structure.
(5) After landing, the safety limiter was power off and the constraint of solar panels
was released. Then solar panels were unfolded to a specified angle and able to
be changed as required to ensure enough power supply. Before the lunar night,
sun panels were folded and powers off to maintain this position until the end of
the lunar night. After the lunar night, solar panels were unfolded by command
and oriented to the Sun.
4. Solar Panel Mechanism Analysis
The solar panel mechanism was also a mechanical component. During launch, the
solar panel mechanism was folded and held down and there was no mechanism to
move, which meant that the solar panel mechanism could be analyzed as a static structural product. The elemental requirement was to satisfy the static (static strength)
and dynamic requirements of the structure. Analysis included modal analysis, static
analysis, sinusoidal vibration response analysis, etc. The analysis method was basically the same as the spacecraft structural analysis. After orbit injection, the solar
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(2) Hold Down and Release Mechanism: To fold sun panels and hold down to
increase strength and rigidity of solar panels to prevent solar panels from being
damaged by the load during launch.
(3) Rotating hinge: For connection of solar panels substrate and lander structure, and to provide support for the single-degree-of-freedom rotation of the
substrate relative to lander structure.
(4) Drive assembly: To provide driving torque for solar panels deployment and
folding, and provide position holding torque for solar panels in specific
position.
(5) Safety limiter. It was used to limit the rotation of solar panels substrate
in landing phase, and improve structural strength and rigidity of solar
panels substrate to avoid damage of solar panels substrate and other related
components (such as rotating hinge) under the landing impact load.
The operation modes of solar panel mechanism are listed as follows for the Chang’E-3
lunar lander:
(1) The solar panels were held down on the top plate of lander structure by Hold
Down and Release Mechanism to withstand load during launch.
(2) After orbit injection, the Hold Down and Release Mechanism was unlocked
and the solar panels were released.
(3) In orbital flight, the sun panels were deployed and oriented toward the Sun. In
order to withstand load at the ignition and stop of the 7500 N engine of the
lunar lander and avoid the influence of engine plume on solar panels, the solar
panels were folded before the main engine ignition and deployed again after
the engine stop. According to the flight procedure, the solar panels should be
folded and unfolded more than once in orbit.
(4) Before powered descent and soft-landing, solar panels were folded to ensure
that it could withstand landing impact load. Then the safety limiter was powered
on to constrain solar panels to improve the strength and stiffness of solar panels
structure.
(5) After landing, the safety limiter was power off and the constraint of solar panels
was released. Then solar panels were unfolded to a specified angle and able to
be changed as required to ensure enough power supply. Before the lunar night,
sun panels were folded and powers off to maintain this position until the end of
the lunar night. After the lunar night, solar panels were unfolded by command
and oriented to the Sun.
4. Solar Panel Mechanism Analysis
The solar panel mechanism was also a mechanical component. During launch, the
solar panel mechanism was folded and held down and there was no mechanism to
move, which meant that the solar panel mechanism could be analyzed as a static structural product. The elemental requirement was to satisfy the static (static strength)
and dynamic requirements of the structure. Analysis included modal analysis, static
analysis, sinusoidal vibration response analysis, etc. The analysis method was basically the same as the spacecraft structural analysis. After orbit injection, the solar