OPS 1427 (OV3-4)

OPS 1427 (OV3-4) is an active satellite operated by USAF OAR (United States), launched on 1966-06-10 from Wallops Flight Facility / MARS, United States on the OV3-4 PHASR launch. After more than 60 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 642 km and 4,681 km with an inclination of 40.9°. It travels at approximately 23,915 km/h (6.64 km/s), completing one full orbit every 2 hours 23 minutes — that’s roughly 10.10 orbits per day. Its orbital eccentricity of 0.2236 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Orbital Radar tracks OPS 1427 (OV3-4) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

OPS 1427 (OV3-4) orbits at an average altitude of 2,662 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 1427 (OV3-4)’s average altitude, there are currently 1 active payload and 5 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 40.9°, OPS 1427 (OV3-4) passes over latitudes between 40.9°N and 40.9°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. United States operates approximately 13,279 active satellites in total.