R5-S4

R5-S4 is an active satellite operated by NASA JSC (United States), launched on 2024-07-04 from Vandenberg Space Force Base, United States on the VCLS Demo-2FB launch. It orbits in Low Earth Orbit (LEO) at altitudes between 414 km and 437 km with an inclination of 97.2°. It travels at approximately 27,569 km/h (7.66 km/s), completing one full orbit every 93 minutes — that’s roughly 15.47 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. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~1–3 years. Orbital Radar tracks R5-S4 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

R5-S4 orbits at an average altitude of 426 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 R5-S4’s average altitude, there are currently 6,973 active payloads and 121 tracked debris or rocket body fragments — notable neighbours include ISS (ZARYA), STARLINK-1017, STARLINK-1039. This makes it one of the more crowded altitude bands, containing roughly 36.8% of all active satellites. With an inclination of 97.2°, R5-S4 passes over latitudes between 97.2°N and 97.2°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 13,340 active satellites in total, of which 6,744 share a similar altitude band with R5-S4.