488
15 System Testing and Validation Technology of Lunar Lander
were acquired by 1:0.3 model in wind tunnel. The LLRV could simulate gravity
environment on lunar surface very well. However, the system was complex, expensive
and of high test cost, and there was potential hazard. During tests, there were accidents
in which the vehicle went out of control and exploded [2, 3].
3. Landing Stability Test
In order to verify the landing gears performance and landing stability of Apollo
lunar module, the 1/6 geometric scale model test under Earth gravity and full-scale
model test under simulation lunar gravity were conducted in the United States The
test results of landing gear stroke, acceleration at mass center and attitude motion
acquired by two methods were in good consistency. The full-scale model could
perfectly reproduce the dynamic process under symmetrical landing condition, which
could be applied to study the stability during landing process.
1) 1/6 scale model test
The 1/6 scale model could satisfy test requirements for structure, size and mass. The
scale model was by material with same yield strength as the full-scale model. When
the 1/6 scale model was tested, it was installed on the release device at the bottom of
single pendulum, as shown in Fig. 15.3. In the test, when the release device passed
through the lowest point of single pendulum, the 1/6 scale test model was released by
release device. Then the test model would move in a parabola at predefined horizontal
velocity and contact with the landing surface to simulate soft landing process [4].
Fig. 15.3 Principle of 1/6 scale model test [4]
15 System Testing and Validation Technology of Lunar Lander
were acquired by 1:0.3 model in wind tunnel. The LLRV could simulate gravity
environment on lunar surface very well. However, the system was complex, expensive
and of high test cost, and there was potential hazard. During tests, there were accidents
in which the vehicle went out of control and exploded [2, 3].
3. Landing Stability Test
In order to verify the landing gears performance and landing stability of Apollo
lunar module, the 1/6 geometric scale model test under Earth gravity and full-scale
model test under simulation lunar gravity were conducted in the United States The
test results of landing gear stroke, acceleration at mass center and attitude motion
acquired by two methods were in good consistency. The full-scale model could
perfectly reproduce the dynamic process under symmetrical landing condition, which
could be applied to study the stability during landing process.
1) 1/6 scale model test
The 1/6 scale model could satisfy test requirements for structure, size and mass. The
scale model was by material with same yield strength as the full-scale model. When
the 1/6 scale model was tested, it was installed on the release device at the bottom of
single pendulum, as shown in Fig. 15.3. In the test, when the release device passed
through the lowest point of single pendulum, the 1/6 scale test model was released by
release device. Then the test model would move in a parabola at predefined horizontal
velocity and contact with the landing surface to simulate soft landing process [4].
Fig. 15.3 Principle of 1/6 scale model test [4]