Traveling through time and space & Doing timey wimy stuff.

On the months of November 2021  天问一号飞運騎遊達达3亿CNSA – China National Space Administration – ESA – European Space agency Belt and road initiative mars mission…first Mars exploration mission, Tianwen- Martian Probe One …….祝融号Zhu Rong”  , China’s “Tianwen One” in cooperation with the European Space Agency “Mars Express” mission team, launched the “Vulcan No.” rover and “Mars Express” orbiter orbit relay communications test and achieved a complete success. Before the test, the respective detectors in both directions must be instructed to make preparations for the test. At the appointed time, the “Zhurong” will send the test data to the “Mars Express”, the communication distance is about 4000 kilometers, and the communication time is 10 minutes. The “Mars Express” receives the data and forwards it to the deep space monitoring and control station of ESA. After receiving the data, the monitoring and control station sends it to the European Space Operations Center (ESOC). The ESOC is then forwarded to the Beijing Aerospace Flight Control Center. After interpretation by the Chinese technical team, Interpret the correctness of the data. The test process is shown in the figure.

Constrained by weight and size, the Mars rover has weak direct-to-ground communication capabilities and cannot meet the demand for large amounts of data transmission. Therefore, the data needs to be sent to the Mars orbiter that is closer, and the orbiter with stronger communication capability is forwarded to the ground receiving system. , This process is called relay communication.

Under normal circumstances, before establishing relay communication, the orbiter will first send an “initiate” signal to the rover, and then the rover will reply with an “confirmation” signal, and then the two parties will establish a stable two-way relay communication link, just like a friend calling The phone needs to be dialled first. Since the launch frequency of the “Mars Express” does not match the receiving frequency of the “Zhurong”, the communication link cannot be established by “dialling a phone”. The transmission frequency of “Zhurong” matches the receiving frequency of “Mars Express”. Therefore, both parties need to agree on a communication time in advance. The “Zhurong” sends data directly and “Mars Express” performs “blind reception”, which is a bit similar to the communication method of WeChat. . The “Mars Express” orbiter has a “blind harvest” function, but there has been no chance to actually use this function for more than a decade.

ESA stated that this test is a good opportunity for the “Mars Express” to verify the “blind harvest” model in orbit. According to the results of data interpretation and analysis, the mission teams of both parties confirmed that the interfaces of the relay communication equipment configured on the “Zhurong” and the “Mars Express” match conform to international standards, and the content of the transmitted data is complete and correct, and the test is a success. In the future, the two parties will further carry out scientific data relay communication cooperation on the basis of this phase of experimentation. The “Zhurong” rover currently works on the surface of Mars for 196 Mars days, has travelled 1,297 meters in total, and obtained about 10GB of raw scientific data for inspections and explorations. It has sufficient energy and is in good condition.






作者:耿言 陈刚

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