KYOKKO 1 (EXOS A)

KYOKKO 1 (EXOS A) is an active satellite operated by Japan, launched on 1978-02-04 from Uchinoura, Japan on the EXOS-A launch. With over 48 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 640 km and 3,938 km with an inclination of 65.4°. It travels at approximately 24,424 km/h (6.78 km/s), completing one full orbit every 2 hours 14 minutes — that’s roughly 10.76 orbits per day. Its orbital eccentricity of 0.1904 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Orbital Radar tracks KYOKKO 1 (EXOS A) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

KYOKKO 1 (EXOS A) orbits at an average altitude of 2,289 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of KYOKKO 1 (EXOS A)’s average altitude, there are currently 1 active payload and 8 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 65.4°, KYOKKO 1 (EXOS A) passes over latitudes between 65.4°N and 65.4°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. Japan operates approximately 190 active satellites in total.