OPS 7518 (NTS 1)

OPS 7518 (NTS 1) is an active satellite operated by SAMSO (United States), launched on 1974-07-14 from Vandenberg Space Force Base, United States on the NTS 1 launch. After more than 52 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 13,479 km and 13,741 km with an inclination of 125.0°. It travels at approximately 16,079 km/h (4.47 km/s), completing one full orbit every 7 hours 49 minutes — that’s roughly 3.07 orbits per day. Orbital Radar tracks OPS 7518 (NTS 1) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

OPS 7518 (NTS 1) orbits at an average altitude of 13,610 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 OPS 7518 (NTS 1)’s average altitude, there are currently 2 active payloads and 11 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 125.0°, OPS 7518 (NTS 1) passes over latitudes between 125.0°N and 125.0°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. United States operates approximately 13,279 active satellites in total.