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11 Landing Gear Technology of Lunar Lander
11.6 Testing and Verification
The landing gear mechanism was a multi-function mechanism including hold-down,
deploy and lock-up, landing impact cushion, lunar surface sensing and support for
the lunar lander, which was totally different with common mechanism, especially
in ground testing and verification. During research and development of the landing
gear mechanism, tests should be conducted, such as static and impact test of cushion
material, assembly static test, friction test, deployment test, landing cushion test
and environmental adaptability test of landing gear mechanism, as well as systemlevel cushion performance verification and landing stability test of the lunar lander,
which were very complex in test status. Only some typical test and verification are
introduced in this section.
11.6.1 Performance Verification of Cushion Material
Performance verification of cushion material included static test and impact test. In
preliminary design, static test and impact test were conducted to acquire cushion characteristics and bearing strength and to determine dimension or size of cushion material to meet specific requirements. In manufacture process of flight hardware, such
tests should be conducted for cushion material to check the stability and consistency
of cushion performance.
1. Static Test of Cushion Material
Static test of cushion material was generally conducted on universal test machine, as
shown in Fig. 11.19.
For example, the aluminum honeycomb was machined to demanded profile at
first; then put them into a dedicated loading tool; at last the load was applied on
the aluminum honeycomb by universal test machine and the curves of load versus
deformation is recorded.
A typical load versus deformation curve of aluminum honeycomb is shown in
Fig. 11.4. It was shown that the load climbed rapidly to a peak at initial phase and
significantly dropped down, then maintained a level stage as deformation increases,
and in the end, the curve drastically climbed up which imply that the aluminum
honeycomb was compressed into a solid block.
2. Impact Test of Cushion Material
Impact test of cushion material was generally conducted on dedicated impact test
bed. Under specific load condition, the impact test bed provided sufficient impact
velocity to ensure that the cushion material was fully stretched or compressed. The
cushion impact test on the landing impact test bed was shown in Fig. 11.20. For
example, at first, the aluminum honeycomb was pushed into piston cylinder; then
the piston cylinder was connected with the gantry and ballast; the gantry was lift up
11 Landing Gear Technology of Lunar Lander
11.6 Testing and Verification
The landing gear mechanism was a multi-function mechanism including hold-down,
deploy and lock-up, landing impact cushion, lunar surface sensing and support for
the lunar lander, which was totally different with common mechanism, especially
in ground testing and verification. During research and development of the landing
gear mechanism, tests should be conducted, such as static and impact test of cushion
material, assembly static test, friction test, deployment test, landing cushion test
and environmental adaptability test of landing gear mechanism, as well as systemlevel cushion performance verification and landing stability test of the lunar lander,
which were very complex in test status. Only some typical test and verification are
introduced in this section.
11.6.1 Performance Verification of Cushion Material
Performance verification of cushion material included static test and impact test. In
preliminary design, static test and impact test were conducted to acquire cushion characteristics and bearing strength and to determine dimension or size of cushion material to meet specific requirements. In manufacture process of flight hardware, such
tests should be conducted for cushion material to check the stability and consistency
of cushion performance.
1. Static Test of Cushion Material
Static test of cushion material was generally conducted on universal test machine, as
shown in Fig. 11.19.
For example, the aluminum honeycomb was machined to demanded profile at
first; then put them into a dedicated loading tool; at last the load was applied on
the aluminum honeycomb by universal test machine and the curves of load versus
deformation is recorded.
A typical load versus deformation curve of aluminum honeycomb is shown in
Fig. 11.4. It was shown that the load climbed rapidly to a peak at initial phase and
significantly dropped down, then maintained a level stage as deformation increases,
and in the end, the curve drastically climbed up which imply that the aluminum
honeycomb was compressed into a solid block.
2. Impact Test of Cushion Material
Impact test of cushion material was generally conducted on dedicated impact test
bed. Under specific load condition, the impact test bed provided sufficient impact
velocity to ensure that the cushion material was fully stretched or compressed. The
cushion impact test on the landing impact test bed was shown in Fig. 11.20. For
example, at first, the aluminum honeycomb was pushed into piston cylinder; then
the piston cylinder was connected with the gantry and ballast; the gantry was lift up