| In the coming decades, China will implement the manned lunar landing program,which can not be fulfilled without the support of the TT&C(Telemetry, Track andCommand) and Communication system. The Lunar Relay Satellite (LRS) constellationis an indispensable part of the system. The LRS constellation refers to the satelliteconstellation established near the moon, which could provide continuous coverage forthe surface of the moon under specific lunar probe tasks. The LRS constellation couldprovide services of navigation&positioning, communications&relay and orbitmeasuring&determination for the astronauts, exploration vehicles on the lunar surface,and for the lunar orbiter. With the accelerated pace of China’s lunar exploration, thedemand for a variety of tasks is increasing. The ground station can not provideuninterrupted, continuous coverage for the lunar surface, so the construction of the LRSconstellation is the primary task for China’s future lunar exploration and manned lunarlanding projects.In light of this, this paper has conducted special studies on the LRS constellation toprovide the necessary technical support for the successful completion of the Chinesemanned lunar landing project. This paper has given the method of designing andevaluating of the LRS constellation, then designed and evaluated the LRS constellations,and finally selected the optimal constellation, which well meets the needs of theChinese manned lunar landing mission. This paper established different LRSconstellations for different missions. In-depth theoretical study and simulation analysishave been done for the constellations with different achitatures, such as high, low lunarsurrounding orbit and Earth-Moon libration point orbit. The detail aspects includesatellites’ force model, constellation architecture, coverage performance, linkperformance, deploy method of the constellation, maintainence of the constellation andthe cost of the constellation and so on.Research, design, analysis and assessment of the following different types of lunarrelay constellations have been done:(1) Lunar south pole coverage relay constellation:which is built for the lunar south pole area manned lunar landing mission, and is used tomeet the requirements of providing continuous coverage to the lunar spacecraft and the lunar surface exploration unit at a specific time and in a specific area.(2) Lunarbackside coverage relay constellation: which is built for the lunar backside areamanned lunar landing mission, and is used to meet the requirements of providingcontinuous coverage to the lunar spacecraft and the lunar surface exploration unit at aspecific time and in a specific area.(3) Full-coverage LRS constellation: which is builtfor the latter manned lunar landing mission, and is used to meet the requirements ofproviding continuous coverage to the lunar spacecraft and the lunar surface explorationunit at any time and in any area. Finally the optimal ones have been chosen out usingthe constellation evaluation method. And reasonable and feasible proposals for theconstruction of the Chinese LRS constellation have been offered. |
