1、QUESTION ITU-R 222-1/7*Radio links between earth stations and lunar and planetary missions by means of lunar and/or planetary data relay satellites (1997-2003) The ITU Radiocommunication Assembly, considering a) that many space research spacecraft and space stations will require continuous communica
2、tion with earth stations; b) that the technical characteristics and operational requirements of inter-planetary links via lunar and/or planetary data relay satellites are different from those of direct links between earth stations and stations on lunar and planetary missions; c) that there are many
3、advantages in the use of lunar and/or planetary data relay satellites to transfer data to or from stations on lunar and/or planetary missions; d) that relay stations can communicate with several spacecraft and space stations that have no line-of-sight links to the earth stations; e) that these lunar
4、 and/or planetary data relay satellites are used for radiocommunication with manned as well as unmanned space stations; f) that the orbital requirements for such relay stations will vary based on the mission requirements, recognizing 1 that there is a shielded zone of the Moon for radio astronomy ob
5、servation referred to in No. 22.22 of the Radio Regulations, decides that the following Question should be studied 1 What are the preferred frequency bands and bandwidth? 2 What are the orbital requirements of lunar and planetary data relay satellites? 3 What are the operational requirements for rad
6、iocommunication links between earth stations and space stations by means of lunar and/or planetary data relay satellites? 4 What are the technical characteristics for radiocommunication links between earth stations and space stations by means of lunar and/or planetary data relay satellites? 5 What a
7、re the requirements for sharing with other services? _ *In the year 2009, Radiocommunication Study Group 7 extended the completion date of studies for this Question. - 2 - further decides 1 that the results of the above studies should be included in one or more Recommendations; 2 that characterization of the present and future relay systems for Mars missions should be provided by 2011; 3 that a description of a conceptual lunar relay system should be provided by 2011.
