Cheollian 1, Korea's first geostationary satellite, ended operations after completing a 16-year mission.
Korea Aerospace Research Institute (KARI) said it completed the disposal maneuver and component deactivation procedures for Cheollian 1 at 1:32 a.m. on the 8th. As a result, the weather, ocean observation, and communications missions that had continued since its launch in June 2010 were also finally terminated.
The disposal process proceeded by cutting power to the satellite's payloads and moving it to a disposal orbit about 300 km higher than its original geostationary orbit. The geostationary orbit is located at an altitude of about 35,786 km above Earth, and leaving a defunct satellite in that orbit can cause collision risks with other satellites or frequency interference.
KARI raised Cheollian 1's altitude through a total of six maneuvers. It then vented the remaining fuel, deactivated the propulsion and power systems, and completely shut down the power.
Cheollian 1 operated for 16 years, exceeding its original design life of seven years. The distance it traveled reached about 1.6 billion km. At the time of launch, Korea became the seventh country in the world to possess a weather observation satellite and laid the groundwork to independently secure some weather information that had relied on foreign data.
In particular, the weather payload captured about 560,000 images over roughly nine years and was used to observe disaster weather phenomena such as typhoons and heavy rainfall. The ocean payload produced about 30,000 images and was used for red tide observation in the West Sea and South Sea and for monitoring marine pollution. The communications payload provided Korea's first satellite communications test service using a geostationary satellite, serving as a foundation for related technology development.
The orbital slot and frequency resources used by Cheollian 1 will be succeeded by the follow-on satellite Cheollian 3. The weather mission carried out by Cheollian 1 is being performed by Cheollian 2A, and the ocean mission by Cheollian 2B.
Lee Sang-cheol, president of KARI, said, "Cheollian 1, Korea's first geostationary satellite, has carried out weather and ocean observation and communications missions over the past 16 years," adding, "It is a case of accumulating full life-cycle operational experience for national satellites in that we completed the procedure to clear the orbit for follow-on satellites after the mission ended."