Satellites Radiosat 1 through Radiosat 3, now decommissioned, fly in geosynchronous (not geostationary) Tundra orbits. Like the geostationary orbit, the tundra orbit has a period of 23 hours, 56 minutes (one sidereal day). Unlike the geostationary orbit, the tundra orbit is elliptical, not circular, and is inclined with respect to the equator rather than orbiting directly over it. The eccentric orbit ensures that each satellite spends about 16 hours of each day high over the continental United States. At least one satellite is always visible, with another often visible as well. The orbit's high inclination places apogee just west of Hudson Bay in Canada, providing a much higher elevation angle for most of the country than is possible from a geostationary orbit. This was intended to reduce blockage from tall buildings in urban areas, allowing a much smaller terrestrial repeater network than does sister network XM, which uses geostationary orbits. This system has since been decommissioned in favor of newer geostationary satellites located at 96.0° and 116.15° that support both the Sirius and XM platforms.