490
15 System Testing and Validation Technology of Lunar Lander
~ 1066.8 mm, which could provide an impact velocity range of 2.04–4.57 m/s.
Total 16 tests were conducted for LTA-3. Six of them were reduced-level tests.
The reduced-level test was accomplished with a special test landing gear that used
cartridges with crush characteristics equal to 75% of flight hardware [6–8].
5. Plume Effect Test
In the Apollo mission, the plume of the 16 attitude control engines in the service
module would act on the surface of the service module and the lunar module. The
plume of the land engine during landing would act on the landing gears and the lower
surface of the descent module. Therefore, special plume protection was necessary
for the surface of the service module and the lunar module, and the landing gears.
The plume impact tests were applied to verify the effectiveness of the protection.
During development of Apollo, in the full-scale attitude control thrust system
(RCS) plume impact test conducted in the Space Environment Simulation Laboratory (SESL), the full-scale lunar module system validation test was completed.
Meanwhile, a full-scale descent profile was applied for the plume impact test to
acquire the plume heating flux and pressure data [9].
15.2.2 System Test Implemented in the Soviet Union
In order to verify the strength and dynamics of the lunar lander, in the Soviet Union
lunar exploration program, drop experiment to simulate the landing conditions on
lunar surface based on the principle of energy equivalence was conducted. Under
Earth gravity, it could simulate the landing process of the lunar lander with same
landing energy as the lunar landing process. In the experiment, the attitude parameters
and velocity parameters of the lunar lander were simulated when the lunar lander
touched lunar surface.
The drop test platform for the lunar lander is shown in Fig. 15.5. It consisted of
following parts.
(1) Landing platform: The angle between the landing platform and the horizontal
plane could be adjusted, and the maximum slope of the landing surface could
be simulated at 20°.
(2) Needle shaped steel frame structure: It consisted of winch and steel cable,
which can be applied to provide the lunar lander test model with initial landing
velocity parameters and attitude parameters.
(3) Simulated lunar soil: The medium hardness soil was used to simulate lunar
soil, and the bearing strength of the simulated lunar soil was 34.3 ~ 49 kPa/cm.
(4) Electric lock: It was applied to release the lunar lander simulation at predefined
position.
(5) Camera: It was used to record the test process.
The needle shaped steel frame structure consisted of winch and steel cable with
electric lock, by which the initial drop height of the lunar lander test model could
15 System Testing and Validation Technology of Lunar Lander
~ 1066.8 mm, which could provide an impact velocity range of 2.04–4.57 m/s.
Total 16 tests were conducted for LTA-3. Six of them were reduced-level tests.
The reduced-level test was accomplished with a special test landing gear that used
cartridges with crush characteristics equal to 75% of flight hardware [6–8].
5. Plume Effect Test
In the Apollo mission, the plume of the 16 attitude control engines in the service
module would act on the surface of the service module and the lunar module. The
plume of the land engine during landing would act on the landing gears and the lower
surface of the descent module. Therefore, special plume protection was necessary
for the surface of the service module and the lunar module, and the landing gears.
The plume impact tests were applied to verify the effectiveness of the protection.
During development of Apollo, in the full-scale attitude control thrust system
(RCS) plume impact test conducted in the Space Environment Simulation Laboratory (SESL), the full-scale lunar module system validation test was completed.
Meanwhile, a full-scale descent profile was applied for the plume impact test to
acquire the plume heating flux and pressure data [9].
15.2.2 System Test Implemented in the Soviet Union
In order to verify the strength and dynamics of the lunar lander, in the Soviet Union
lunar exploration program, drop experiment to simulate the landing conditions on
lunar surface based on the principle of energy equivalence was conducted. Under
Earth gravity, it could simulate the landing process of the lunar lander with same
landing energy as the lunar landing process. In the experiment, the attitude parameters
and velocity parameters of the lunar lander were simulated when the lunar lander
touched lunar surface.
The drop test platform for the lunar lander is shown in Fig. 15.5. It consisted of
following parts.
(1) Landing platform: The angle between the landing platform and the horizontal
plane could be adjusted, and the maximum slope of the landing surface could
be simulated at 20°.
(2) Needle shaped steel frame structure: It consisted of winch and steel cable,
which can be applied to provide the lunar lander test model with initial landing
velocity parameters and attitude parameters.
(3) Simulated lunar soil: The medium hardness soil was used to simulate lunar
soil, and the bearing strength of the simulated lunar soil was 34.3 ~ 49 kPa/cm.
(4) Electric lock: It was applied to release the lunar lander simulation at predefined
position.
(5) Camera: It was used to record the test process.
The needle shaped steel frame structure consisted of winch and steel cable with
electric lock, by which the initial drop height of the lunar lander test model could