The Japanese government will decide by the end of this year whether to finance a second and third Quasi-Zenith Satellite System (QZSS) positioning and navigation spacecraft and thus make the system fully operational, or to stop at the lone QZSS satellite now in orbit, according to Koji Terada, QZSS project manager at Japan’s space agency, JAXA.
Addressing the Munich Satellite Navigation Summit March 3, Terada said the QZSS satellite launched in September 2010, named Michibiki or “guiding light” in Japanese, has successfully completed its in-orbit checkout.
The satellite is in a highly elliptical orbit that allows it to remain at a high elevation angle over Japan for relatively long periods. Three such satellites would be required to provide a fully functioning service. Terada said early tests of Michibiki have shown that, when used with U.S. GPS satellites, users anywhere in Japan have an 84.7 percent chance of receiving steady signals. With GPS alone, he said, the rate is just 73 percent.
Terada said Michibiki would be set at “healthy” status in the next three months, when its signal passes further qualification tests. It is at that point, he said, that an eight-ministry government body, called the QZSS Project Team, will decide whether the program should be expanded.