5.6 Testing and Verification
185
physical properties of the lunar lander surfaces resulting in temperature raise,
the effect of lunar dust on the test conditions should be considered. In addition,
because the distribution of external heat flow in circumlunar phase and operation on lunar surface was different, the high temperature conditions should be
considered separately. The major external heat flow was solar radiation heat
flow in LTO and there were few of instruments on operation at cruise attitude,
therefore the whole the lunar lander probe was generally at low temperature.
In a circumlunar orbit period, there were generally conditions including in
illumination and in lunar shadow during different time. For exposed components and some instruments in modules, high temperature conditions and low
temperature conditions might occur in one orbital period. Thus, there should
be high temperature conditions and low temperature conditions in circumlunar
phase.
(2) The transient conditions should generally be verified in the test. For a shorttime transient process such as landing, the operation mode of the lunar lander
was quite different from other phases, while the external heat flow varied
greatly, which caused the temperature of instruments affected by transient
characteristics greatly. In order to obtain the temperature change of instruments
accurately and provide more detailed data for correction of thermal analysis
model, it generally should be verified directly.
(3) Special test conditions should be set for requirements of thermal analysis and
calculation. Due to limited number of thermal test conditions, a large number
of thermal analysis and calculations should be conducted to predict the temperature in all mission phases for the lunar lander. Therefore, it was very important
to improve the accuracy of thermal analysis model. Generally, relatively simple
external heat flow conditions or other on-orbit conditions easy to be simulated
accurately should be selected for verification of thermal analysis model. Or it
could also be included in other test conditions of high and low temperature.
Test conditions such as LTO phase or noon on lunar surface were suitable for
verification of thermal analysis model.
(4) Test conditions including lunar night and wakeup should be set to verify the
lowest temperature of the lunar lander in lunar night and the temperature
changes in wakeup process. The lunar night was the most typical environment condition for long-term lunar land which was harsh. The lunar night
condition should be set to verify the temperature level and distribution of the
lunar lander. Since the temperature changes in wakeup process was related to
the temperature in lunar night, the wakeup condition was generally set after the
lunar night condition. Since the time of lunar night was as long as 14 days and
the temperature was generally dropping down in lunar night, the criterion of
temperature balance in the lunar night condition should be stricter than usual.
185
physical properties of the lunar lander surfaces resulting in temperature raise,
the effect of lunar dust on the test conditions should be considered. In addition,
because the distribution of external heat flow in circumlunar phase and operation on lunar surface was different, the high temperature conditions should be
considered separately. The major external heat flow was solar radiation heat
flow in LTO and there were few of instruments on operation at cruise attitude,
therefore the whole the lunar lander probe was generally at low temperature.
In a circumlunar orbit period, there were generally conditions including in
illumination and in lunar shadow during different time. For exposed components and some instruments in modules, high temperature conditions and low
temperature conditions might occur in one orbital period. Thus, there should
be high temperature conditions and low temperature conditions in circumlunar
phase.
(2) The transient conditions should generally be verified in the test. For a shorttime transient process such as landing, the operation mode of the lunar lander
was quite different from other phases, while the external heat flow varied
greatly, which caused the temperature of instruments affected by transient
characteristics greatly. In order to obtain the temperature change of instruments
accurately and provide more detailed data for correction of thermal analysis
model, it generally should be verified directly.
(3) Special test conditions should be set for requirements of thermal analysis and
calculation. Due to limited number of thermal test conditions, a large number
of thermal analysis and calculations should be conducted to predict the temperature in all mission phases for the lunar lander. Therefore, it was very important
to improve the accuracy of thermal analysis model. Generally, relatively simple
external heat flow conditions or other on-orbit conditions easy to be simulated
accurately should be selected for verification of thermal analysis model. Or it
could also be included in other test conditions of high and low temperature.
Test conditions such as LTO phase or noon on lunar surface were suitable for
verification of thermal analysis model.
(4) Test conditions including lunar night and wakeup should be set to verify the
lowest temperature of the lunar lander in lunar night and the temperature
changes in wakeup process. The lunar night was the most typical environment condition for long-term lunar land which was harsh. The lunar night
condition should be set to verify the temperature level and distribution of the
lunar lander. Since the temperature changes in wakeup process was related to
the temperature in lunar night, the wakeup condition was generally set after the
lunar night condition. Since the time of lunar night was as long as 14 days and
the temperature was generally dropping down in lunar night, the criterion of
temperature balance in the lunar night condition should be stricter than usual.