Chapter 13
Metrology Technology of Lunar Lander
13.1 Introduction
During system integration of the lunar lander, metrology technology was applied in
alignment accuracy measurement, seal performance measurement and mass property
measurement. The alignment accuracy measurement was to acquire the geometry
information of structure size, position and angle. The seal performance measurement
was to examine the leakage rate of seal components of propulsion subsystem. The
mass properties measurement was to acquire the information of mass, center of mass
and inertia after the lunar lander was integrated and assembled [1].
Metrology technology played an important role in development of system integration of the lunar lander. In order to ensure high accuracy of attitude determination,
attitude control and orbit control of the lunar lander on orbit, during the system
integration, it was necessary to apply geometry metrology technology to ensure the
installation accuracy of highly accurate instruments, such as gyroscope, accelerometer, star sensor, radar ranging and speedometer and laser ranging sensor, as well as
actuators including 10 N thrusters, 150 N thrusters and 7500 N throttling engine.
At the same time, accurate pointing data after assembly should also be acquired
for requirements of onboard computer to formulate strategy of attitude control and
orbit control. The mass property measurement method should be applied to acquire
mass property data including mass, mass center and inertia, as well as help to adjust
during assembly, and then provide important parameters for attitude control of the
lunar lander. In order to ensure effective utilization of liquid and gas and no leak in
propulsion subsystem of the lunar lander on orbit, during assembly process, different
methods should be applied to examine the seal performance of propulsion subsystem,
so as to find defect in propulsion subsystem and take effective remedial measures.
In order to satisfy requirements for measurement and control in landing process
of the lunar lander, higher technical requirements for assembly geometry accuracy, seal performance and mass property were come up compared with conventional spacecraft. In this chapter, the characteristics of metrology of the lunar lander
are analyzed. Development status of metrology technology is introduced. Special
© National Defense Industry Press and Springer Nature Singapore Pte Ltd. 2021
D.-Y. Yu et al., Technology of Lunar Soft Lander, Space Technology Library 38,
https://doi.org/10.1007/978-981-15-6580-9_13
435
Metrology Technology of Lunar Lander
13.1 Introduction
During system integration of the lunar lander, metrology technology was applied in
alignment accuracy measurement, seal performance measurement and mass property
measurement. The alignment accuracy measurement was to acquire the geometry
information of structure size, position and angle. The seal performance measurement
was to examine the leakage rate of seal components of propulsion subsystem. The
mass properties measurement was to acquire the information of mass, center of mass
and inertia after the lunar lander was integrated and assembled [1].
Metrology technology played an important role in development of system integration of the lunar lander. In order to ensure high accuracy of attitude determination,
attitude control and orbit control of the lunar lander on orbit, during the system
integration, it was necessary to apply geometry metrology technology to ensure the
installation accuracy of highly accurate instruments, such as gyroscope, accelerometer, star sensor, radar ranging and speedometer and laser ranging sensor, as well as
actuators including 10 N thrusters, 150 N thrusters and 7500 N throttling engine.
At the same time, accurate pointing data after assembly should also be acquired
for requirements of onboard computer to formulate strategy of attitude control and
orbit control. The mass property measurement method should be applied to acquire
mass property data including mass, mass center and inertia, as well as help to adjust
during assembly, and then provide important parameters for attitude control of the
lunar lander. In order to ensure effective utilization of liquid and gas and no leak in
propulsion subsystem of the lunar lander on orbit, during assembly process, different
methods should be applied to examine the seal performance of propulsion subsystem,
so as to find defect in propulsion subsystem and take effective remedial measures.
In order to satisfy requirements for measurement and control in landing process
of the lunar lander, higher technical requirements for assembly geometry accuracy, seal performance and mass property were come up compared with conventional spacecraft. In this chapter, the characteristics of metrology of the lunar lander
are analyzed. Development status of metrology technology is introduced. Special
© National Defense Industry Press and Springer Nature Singapore Pte Ltd. 2021
D.-Y. Yu et al., Technology of Lunar Soft Lander, Space Technology Library 38,
https://doi.org/10.1007/978-981-15-6580-9_13
435