Mission typeCommunication
COSPAR ID2010-032A
SATCAT no.36744
Mission duration7 years
Spacecraft properties
ManufacturerEADS Astrium
Launch mass2,460 kilograms (5,420 lb)
Power2.5 kilowatts
Start of mission
Launch date26 June 2010, 21:41 (2010-06-26UTC21:41Z) UTC
RocketAriane 5ECA
Launch siteKourou ELA-3
Orbital parameters
Reference systemGeocentric
Longitude128.2° East
Perigee altitude35,791 kilometres (22,239 mi)[1]
Apogee altitude35,795 kilometres (22,242 mi)[1]
Inclination0.03 degrees[1]
Period1436.13 minutes[1]
Epoch23 January 2015, 17:05:20 UTC[1]

Chollian, (Korean: 천리안, lit. Thousand Li View, clairvoyance)[2] also known as Communication, Ocean and Meteorological Satellite 1[3] (COMS-1), is a South Korean satellite which was launched in June, 2010. It will be operated by the Korea Aerospace Research Institute, who will use it for communication, oceanography, and meteorological observation.

COMS-1 was constructed by EADS Astrium, and is based on the Eurostar-3000S satellite bus, bringing together lessons learned from Eurostar satellites and NASA-made GOES satellites respectively. It has a mass of 2,460 kilograms (5,420 lb), and carries transponders broadcasting in the D/E and K bands of the NATO-defined spectrum, or the L/S and Ka bands of the IEEE-defined spectrum respectively. Its single solar array is expected to generate a minimum of 2.5 kilowatts of power.[4]

COMS-1 was launched by Arianespace using an Ariane 5ECA carrier rocket lifting off from ELA-3 at the Guiana Space Centre in Kourou, French Guiana. The first attempt to launch it occurred on 23 June 2010, however the launch was scrubbed due to a problem with one of the rocket's subsystems.[5] A subsequent attempt on 24 June was also scrubbed, due to a problem with the pressurisation of the rocket's fuel tanks.[6] The launch occurred at 21:41 UTC on 26 June 2010.[6][7] The Saudi Arabian Arabsat-5A satellite was launched by the same rocket, with a SYLDA adaptor being used to separate the spacecraft. Arabsat-5A was mounted atop the SYLDA, with COMS-1 underneath it.[8]

Following launch, COMS-1 separated into a geosynchronous transfer orbit. It will use an apogee motor to raise itself into geosynchronous orbit. Once it reaches this orbit, it will undergo testing before beginning operations at a longitude of 128.2 degrees East.[9] Its mission is scheduled to last seven years,[4] however the satellite has a design life of ten years.[10]

As follow-up satellites to Chollian-1, Chollian-2A and Chollian-2B were launched in December 2018 and in February 2020 respectively.[11]


  1. ^ a b c d e "COMS 1 Satellite details 2010-032A NORAD 36744". N2YO. 23 January 2015. Retrieved 25 January 2015.
  2. ^ McDowell, Jonathan (28 June 2010). "Issue 629". Jonathan's Space Report. Archived from the original on 24 October 2010. Retrieved 29 June 2010.
  3. ^ "Space Programs in Korea" (PDF). Asia Pacific Space Activity Forum. December 2006. p. 18. Retrieved 26 June 2010.
  4. ^ a b Krebs, Gunter. "COMS 1". Gunter's Space Page. Retrieved 26 June 2010.
  5. ^ "Flight 195 – Arabsat-5A - COMS: Launch delayed". Arianespace. 23 June 2010. Retrieved 26 June 2010.
  6. ^ a b "Arianespace launch 195 – Arabsat-5A and COMS: Liftoff is set for Saturday, June 26, 2010". Arianespace. 26 June 2010. Retrieved 26 June 2010.
  7. ^
  8. ^ "Ariane 5 Does The Heavy Lifting For Arabsat-5A and COMS". Satnews Daily. 21 June 2010. Archived from the original on 16 July 2011. Retrieved 23 June 2010.
  9. ^ "Satellite Launches for the Middle East and South Korea" (PDF). Arianespace. Archived from the original (PDF) on 4 July 2010. Retrieved 26 June 2010.
  10. ^ "COMS". EADS Astrium. Archived from the original on 15 July 2010. Retrieved 26 June 2010.
  11. ^ "South Korea's Chollian-2B Environmental Satellite To Launch In February 2020". Spacewatch.