Yuanwang 3, a ship affiliated with China’s Satellite maritime Tracking and Control Department, escorted the Chang ‘e-5 spacecraft on its way back to the surface of the Indian Ocean early Sunday morning.
In this mission, yuanwang 3 is the only maritime tracking and control force, which needs to complete telemetry, external measurement and optical measurement missions near the black barrier of the initial reentry of the reentry vehicle.Zhang Wei, chief dispatch officer of Yuanwang 3, said: “During the mission, the unified measurement and control equipment of The S-band of Yuanwang 3 will issue the attitude adjustment instruction in the first time within the short 100-second window before the returner enters the black barrier.The photoelectric theodolite undertakes the optical tracking task of the returnee and provides the flight image information of the returnee.Monopulse radar is mainly responsible for the measurement of the black barrier area of the returver. It provides reliable measurement data for the whole region. It is the first step of the returver’s relay measurement and control into the atmosphere and also an important link in the whole measurement and control support system.
It is understood that the returner can only be captured and tracked by ship-borne monopulse radar and photoelectric theodolite in the black barrier, which seems to be only a short 3 minutes, but the difficulty of measurement and control is beyond imagination.
Wang Erjian, an engineer in the general technology department of the China Satellite Maritime Tracking and Control Department, explained the complicated measurement and control process: “Optical tracking equipment is like using the naked eye to look for meteors flying in the sky with high speed through a telescope. The target flies very fast and is very difficult to catch.And the ship carrying the monopulse radar search beam is narrow, and return on no response signal of heaven and earth, need to use the plasma shell reflection signal tracking radar, plasma shell surface is very irregular, reflecting signal fluctuation is very big, all of these to capture and stable tracking target search brought huge challenges, our technical personnel to resist pressure successfully complete all the steps, contributing to the mission a complete success.”