ET-001D

ET-001D is an active satellite operated by United States, launched on 2026-07-07 from Vandenberg Space Force Base, United States on the Transporter-17 launch. As a relatively recent addition to the catalogue, its orbital elements are well-characterised. It orbits in Low Earth Orbit (LEO) at altitudes between 585 km and 594 km with an inclination of 97.7°. It travels at approximately 27,243 km/h (7.57 km/s), completing one full orbit every 96 minutes — that’s roughly 14.93 orbits per day. Its near-polar, sun-synchronous orbit means it passes over any given point on Earth at approximately the same local solar time, ideal for consistent Earth observation lighting conditions. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~3–10 years. Orbital Radar tracks ET-001D in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ET-001D orbits at an average altitude of 590 km in a sun-synchronous orbit (SSO), a specialised subset of LEO where the orbital plane precesses to maintain a constant angle relative to the Sun. This provides consistent lighting conditions on every pass — essential for Earth observation, weather monitoring and environmental science. Within ±50 km of ET-001D’s average altitude, there are currently 1,557 active payloads and 660 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0050, STARLINK-3005, STARLINK-3090. This makes it one of the more crowded altitude bands, containing roughly 8.3% of all active satellites. With an inclination of 97.7°, ET-001D passes over latitudes between 97.7°N and 97.7°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 13,207 active satellites in total, of which 961 share a similar altitude band with ET-001D.