China succeeded in making the third "Beidou" (the Big Dipper) navigation positioning satellite and the "SINOSAT- I" satellite operate well at the one preset place over the equator. This marks that China-made geo-synchronous satellite has realized a new breakthrough in its ability of orbit controlling.

Geo-synchronous satellites are all working at a certain place 36, 000 kilometers above the equator. Since the orbit surface surrounding the earth has merely 360 degrees, only one satellite is allowed at each place on the surface in order to avoid collision or mutual interference.

However, as geo-synchronous satellites grow in number, there is also an increasingly obvious shortage of vacancies in the space orbit. Scientists of various countries are striving to make two or more satellites operate at the same orbit position without disturbing each other, though there are many hi-tech difficulties ahead.

Presently only a few countries such as the United States, Germany and Japan have mastered the technology.

By People's Daily Online