One of the boosters of the Delta II rocket failed to separate from the first stage of the spacecraft, placing it 5,000 km short of its planned GTO apogee. The satellite had to use up 7.5 years worth of its 12-year lifetime fuel supply to make up the deficiency, shortening Koreasat 1's expected life to about 4.5 years. In order to extend its lifetime, it gave up north–south station-keeping operating in "inclined mode." In the end, the satellite managed to function for 10 years.[4]
The satellite was equipped with a Star 30 solid apogee motor. It carried 625 kg (1,378 lb) of fuel for the apogee motor and 187 kg (412 lb) of hydrazine propellant.[5]
It was eventually positioned in geosynchronous orbit at 116° E operated it at 47.5° E where it was focused on Hungary. The satellite went out of service on December 16, 2005, and was moved to the graveyard orbit. As of March 9, 2007, it was located at 152.88° E drifting at 2.155° W per day.[2]
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).