IRS 1A

IRS 1A is an active satellite operated by India, launched on 1988-03-17 from Baikonur, Kazakhstan. With over 38 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 893 km and 914 km with an inclination of 98.8°. It travels at approximately 26,648 km/h (7.40 km/s), completing one full orbit every 103 minutes — that’s roughly 13.97 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 ~100–500 years. Orbital Radar tracks IRS 1A in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

IRS 1A orbits at an average altitude of 904 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 IRS 1A’s average altitude, there are currently 211 active payloads and 1,306 tracked debris or rocket body fragments. With an inclination of 98.8°, IRS 1A passes over latitudes between 98.8°N and 98.8°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. India operates approximately 108 active satellites in total, of which 3 share a similar altitude band with IRS 1A.