A Proton heavy booster rocket with three Uragan satellites on board was installed on the Baikonur launch pad in Kazakhstan Wednesday. The satellites are intended for the Russian constellation of the Global Navigation Satellite System (GLONASS). The rocket is scheduled to be launched on December 1, a spokesman for the Russian Aerospace Agency has said. Now the functioning of electric circuits of the rocket, the satellites and the launch control post, as well as of other systems, is being checked. GLONASS was set up on the initiative of the Russian Defence Ministry in September 1993, the spokesman said. It allows to locate objects on the Earth's surface with an accuracy of one metre. Simultaneously, 24 satellites must be in orbit. However, the spokesman said, because of their short service life (up to three years), the constellation is now short of satellites. This is why the three satellites to be launched include one trial satellite - Uragan-M. Its service life has been extended 50 to 100 percent. In addition, its instruments have higher resolution. In the future, such satellites will gradually replace old navigation satellites in the constellation, the spokesman for the Aerospace Agency said.