468
14 Electrical Testing Technology of Lunar Lander
(1) The high frequency signal could be tested to accurately determine the operation
status of onboard instruments.
(2) It could avoid the interference of electromagnetic environment of the test site
to the wireless signal.
(3) It could reduce the influence of electromagnetic radiation on human body.
Based on above advantages, wired test mode was applied in general test of the
lunar lander, except the special conditions when wireless test mode should be
applied.
4. Wireless Testing Mode
In the wireless test, the transponder and instruments of TT&C of the lunar lander
were connected with the antenna and signal transmission between the lunar lander and
EGSE was implemented through wireless channel. Generally, the signal quality was
only monitored but not measured. Wireless test mode was applied under following
situations.
(1) To verify wireless channel.
(2) To examine electromagnetic compatibility in EMC test.
(3) Unable to conduct wired test in system assembly process.
Wireless test mode was applied in wireless channel test, EMC test, mechanical
environment test and test at launch site.
5. Local Testing Mode
When the lunar lander was close to ground test equipment and the signal transmission
between the lunar lander and ground system was implemented by high and low
frequency cables, it was the local test. It was usually applied for the test in AIT
facility.
6. Remote Testing Mode
In the remote test, the lunar lander was far away from the test room and it was
impossible to connect the lunar lander with ground test equipment through the test
cable directly. Except that the power supply ground equipment and little of test
equipment were placed close the lunar lander, OCOE equipment, TT&C equipment
and display terminals were placed in the test room. Network signal and TT&C high
frequency signal were transmitted by optical fiber link as shown in Fig. 14.2. Such
mode could shorten test preparation time and improve test efficiency. In environment
test and test at launch site, remote test mode was preferred.
The testing mode of the lunar lander in different test phases is shown in Table
14.1.
14 Electrical Testing Technology of Lunar Lander
(1) The high frequency signal could be tested to accurately determine the operation
status of onboard instruments.
(2) It could avoid the interference of electromagnetic environment of the test site
to the wireless signal.
(3) It could reduce the influence of electromagnetic radiation on human body.
Based on above advantages, wired test mode was applied in general test of the
lunar lander, except the special conditions when wireless test mode should be
applied.
4. Wireless Testing Mode
In the wireless test, the transponder and instruments of TT&C of the lunar lander
were connected with the antenna and signal transmission between the lunar lander and
EGSE was implemented through wireless channel. Generally, the signal quality was
only monitored but not measured. Wireless test mode was applied under following
situations.
(1) To verify wireless channel.
(2) To examine electromagnetic compatibility in EMC test.
(3) Unable to conduct wired test in system assembly process.
Wireless test mode was applied in wireless channel test, EMC test, mechanical
environment test and test at launch site.
5. Local Testing Mode
When the lunar lander was close to ground test equipment and the signal transmission
between the lunar lander and ground system was implemented by high and low
frequency cables, it was the local test. It was usually applied for the test in AIT
facility.
6. Remote Testing Mode
In the remote test, the lunar lander was far away from the test room and it was
impossible to connect the lunar lander with ground test equipment through the test
cable directly. Except that the power supply ground equipment and little of test
equipment were placed close the lunar lander, OCOE equipment, TT&C equipment
and display terminals were placed in the test room. Network signal and TT&C high
frequency signal were transmitted by optical fiber link as shown in Fig. 14.2. Such
mode could shorten test preparation time and improve test efficiency. In environment
test and test at launch site, remote test mode was preferred.
The testing mode of the lunar lander in different test phases is shown in Table
14.1.