SMDC ONE 2.3

SMDC ONE 2.3 is an active satellite operated by US Army Space and Missile Defense Command (United States), launched on 2013-12-06 from Vandenberg SFB, California on the TOPAZ 3 launch. After 13 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 329 km and 406 km with an inclination of 120.5°. It travels at approximately 27,688 km/h (7.69 km/s), completing one full orbit every 92 minutes — that’s roughly 15.67 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is months to ~1 year. Orbital Radar tracks SMDC ONE 2.3 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SMDC ONE 2.3 orbits at an average altitude of 368 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 SMDC ONE 2.3’s average altitude, there are currently 1,243 active payloads and 55 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 120.5°, SMDC ONE 2.3 passes over latitudes between 120.5°N and 120.5°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 12,413 active satellites in total, of which 1,133 share a similar altitude band with SMDC ONE 2.3.