ARC-1

ARC-1 is an active satellite operated by United States, launched on 2015-10-08 from Vandenberg SFB, California on the INTRUDER launch. After 11 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 370 km and 423 km with an inclination of 64.8°. It travels at approximately 27,628 km/h (7.67 km/s), completing one full orbit every 92 minutes — that’s roughly 15.57 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is months to ~1 year. Orbital Radar tracks ARC-1 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ARC-1 orbits at an average altitude of 397 km in the lower reaches of Low Earth Orbit, where atmospheric drag is significant and orbital lifetimes are measured in months to a few years. This is the busiest corridor in space — home to crewed spacecraft, rapid-revisit imaging satellites and the densest part of the Starlink constellation. Within ±50 km of ARC-1’s average altitude, there are currently 1,270 active payloads and 82 tracked debris or rocket body fragments — notable neighbours include STARLINK-1008, STARLINK-1012, STARLINK-1020. This makes it one of the more crowded altitude bands, containing roughly 7.1% of all active satellites. With an inclination of 64.8°, ARC-1 passes over latitudes between 64.8°N and 64.8°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. United States operates approximately 12,673 active satellites in total, of which 1,122 share a similar altitude band with ARC-1.