ISIS 1

ISIS 1 is an active satellite operated by CRC (Canada), launched on 1969-01-30 from Vandenberg Space Force Base, United States on the Isis A launch. After more than 57 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Medium Earth Orbit (MEO) at altitudes between 577 km and 3,440 km with an inclination of 88.4°. It travels at approximately 24,829 km/h (6.90 km/s), completing one full orbit every 2 hours 7 minutes — that’s roughly 11.30 orbits per day. Its orbital eccentricity of 0.1708 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Orbital Radar tracks ISIS 1 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ISIS 1 orbits at an average altitude of 2,009 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of ISIS 1’s average altitude, there are currently 9 active payloads and 31 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 88.4°, ISIS 1 passes over latitudes between 88.4°N and 88.4°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. Canada operates approximately 75 active satellites in total.