Abstract: In response to the stringent requirements for reliable command and telemetry transmission during ground landing and ascending experiments of the LY Lunar Lander, alongside constraints including the absence of RF telemetry and tracking link equipment and the inability to modify the ground control system's status, a wired communication system design methodology based on Time-Triggered Ethernet (TTE) and synchronous serial interfaces was proposed, aiming to high-reliability, low-latency data communication between the integrated validator and the ground during the experiment. Generalized optoelectronic conversion devices were deployed both on the spacecraft and on the ground, classifying and recognizing TTE and serial port signals, and converting them into optical signals. These signals were transmitted via fiber optic cables to establish long-distance, wired interconnection between the integrated validator platform and the ground control system. A high-speed, low-latency, multi-redundant spacecraft-to-ground communication link was established, which providing a highly reliable transmission channel for control commands, telemetry status, and various image data. After multiple ground firing tests, the spacecraft-to-ground communication system achieves a maximum rate of 100Mbit/s and data latency below 6 milliseconds. The results validate the rationality and correctness of the proposed methodology, significantly reducing development costs while ensuring the successful completion of the LY Lunar Lander's ground landing and ascending experiments. The method also offers valuable reference for the design of future lunar and Martian exploration spacecraft.

Key words: landing and ascending, integrated validator, communication system, TTE, optoelectronic conversion