GEO-KOMPSAT-2B

GEO-KOMPSAT-2B, internationally designated 2020-013B and assigned NORAD catalog number 45246, is a South Korean geostationary Earth observation satellite operated by the Korea Aerospace Research Institute (KARI). Launched in February 2020, it represents a significant step in the Republic of Korea's independent space-based environmental monitoring capabilities, with a particular emphasis on tracking atmospheric pollutants across the Asia-Pacific region. The satellite is also widely known by its Korean name, Chollian-2B, continuing a lineage of geostationary missions that KARI has pursued as part of the country's broader ambitions in civil space infrastructure.

Mission and Purpose

Chollian-2B was conceived as an environmental and oceanographic observation platform, with a central focus on monitoring the distribution and movement of fine particulate matter and the aerosols and chemical precursors that contribute to its formation. Fine dust — a persistent and serious public health concern across East Asia — originates from a combination of industrial emissions, vehicle exhaust, agricultural burning, and transboundary transport of dust from arid inland regions. A satellite stationed in geostationary orbit directly above the region is uniquely well-suited to track these phenomena in near-real time, since it can observe the same geographic area continuously rather than making periodic passes like a polar-orbiting platform.

In addition to its atmospheric chemistry role, Chollian-2B carries ocean color monitoring instrumentation, enabling it to gather data on the biological and physical state of surrounding seas — information that is valuable for fisheries management, harmful algal bloom detection, and coastal environmental monitoring. The combination of these two broad observational functions gives the satellite a dual character, serving both meteorological and environmental science communities.

Chollian-2B is a companion to Chollian-2A, a related geostationary satellite that preceded it into orbit. The two are often described as twin or sister satellites, sharing a common heritage in terms of the KOMPSAT (Korea Multi-Purpose Satellite) and GEO-KOMPSAT programs administered by KARI. While Chollian-2A focused more heavily on meteorological imaging, Chollian-2B extends the program's coverage into the environmental monitoring domain. Together, they form a complementary pair providing broad situational awareness of the atmosphere and ocean around the Korean Peninsula and the wider Asia-Pacific region.

The satellite is formally part of the GEO-KOMPSAT-2 program — the name standing for Geostationary Korea Multi-Purpose Satellite, second generation — reflecting a deliberate national investment in geostationary infrastructure that would reduce South Korea's dependence on foreign data sources for environmental and weather intelligence.

Orbit and Tracking

Chollian-2B occupies a geostationary orbit, the class of orbit in which a satellite's orbital period matches the rotation rate of the Earth, causing it to appear stationary relative to the ground below. This characteristic is essential for the satellite's mission: continuous observation of a fixed geographic region is only possible from geostationary altitude.

The satellite's tracked orbital parameters confirm its geostationary status. Its apogee stands at 35,797 km and its perigee at 35,794 km, placing it in an exceptionally circular orbit at an altitude just below the nominal geostationary belt of approximately 35,786 km — the small discrepancy from textbook figures reflecting the slight eccentricity and measurement conventions involved in real-world tracking. The orbital inclination is 0.0°, confirming that the satellite travels in the equatorial plane with no north-south drift, as is expected for a well-maintained operational geostationary asset. Its orbital period is 1,436.2 minutes, very close to one sidereal day, which is precisely the condition required to maintain geostationary lock with a fixed longitude slot.

Under its NORAD catalog ID 45246 and COSPAR international designator 2020-013B, the object is tracked continuously by the U.S. Space Surveillance Network and is cataloged as a payload — distinguishing it from the rocket bodies and debris that accompanied it to orbit during the launch campaign. The "2020-013B" designator indicates it was the second tracked object associated with the thirteenth launch of 2020 to be cataloged internationally.

The satellite was launched on February 17, 2020 (Eastern Standard Time), which corresponds to February 18, 2020 in Korean local time and in UTC — a common source of minor date discrepancies across international references. As of the current catalog data, the satellite remains in orbit and is not known to have decayed or reentered.

Design and Operator

Chollian-2B is operated by the Korea Aerospace Research Institute, the primary government space agency of South Korea, headquartered in Daejeon. KARI was established in 1989 and has since overseen a wide range of programs spanning launch vehicle development, satellite manufacturing, and space science. The GEO-KOMPSAT-2 program represents one of KARI's most operationally significant undertakings in the geostationary domain, aimed at providing the Republic of Korea with sovereign remote sensing data for public benefit.

The satellite's manufacturer is not recorded in public tracking catalogs, and its mass is similarly not available in the verified public record for this entry. While detailed spacecraft specifications are not confirmed here, geostationary environmental monitoring satellites of this class are generally substantial platforms — typically in the range of several hundred kilograms to a few tonnes at launch — incorporating large solar arrays, precise attitude control systems, and optical payloads designed for high-sensitivity spectroscopic observation. However, no specific mass figure is stated for Chollian-2B in the available catalog data, and none is asserted here.

The choice of geostationary orbit for this mission reflects a deliberate operational philosophy. Unlike low Earth orbit imagers, which provide high spatial resolution but can only revisit a given location once or a few times per day, a geostationary platform sacrifices some resolution in exchange for the ability to observe the same region continuously, hour after hour. For atmospheric chemistry applications — where the movement of pollution plumes can shift dramatically over the course of a single day — this temporal continuity is not merely convenient but scientifically essential.

Significance and Current Status

The deployment of Chollian-2B marked a meaningful milestone in South Korea's environmental monitoring infrastructure. Prior to its operation, the country and its regional neighbors relied heavily on data from American and European geostationary satellites, or on polar-orbiting platforms with limited temporal resolution, for atmospheric chemistry information. By fielding a dedicated geostationary sensor optimized for aerosol and trace gas monitoring, South Korea positioned itself at the frontier of space-based air quality surveillance — a capability of direct importance to public health policy, transboundary pollution diplomacy, and climate science.

The satellite's focus on fine dust and atmospheric particulates resonates strongly with policy concerns shared across Northeast Asia. Persistent episodes of hazardous air quality affect populations in South Korea, Japan, China, and surrounding regions, and the sources of these events are often geographically diffuse and meteorologically complex. Satellite data capable of resolving the spatial and temporal evolution of pollution events in near-real time provides an evidence base that ground monitoring networks alone cannot supply. Chollian-2B's atmospheric instrument suite is designed to contribute directly to this kind of analysis.

Chollian-2B's companion role alongside Chollian-2A also illustrates a broader trend in national space programs: the value of building families of related satellites that, in combination, deliver capabilities exceeding what any single platform can achieve. The meteorological functions anchored by Chollian-2A and the environmental focus of Chollian-2B together give KARI and South Korean government agencies a layered view of the atmosphere and ocean that supports a range of operational and scientific applications.

As of the latest available catalog data, Chollian-2B remains in its geostationary orbit and continues to be tracked as an active payload. No reentry or decay event has been recorded. The satellite's 0.0° inclination and near-circular orbit at geostationary altitude indicate that active station-keeping maneuvers are being performed to maintain its assigned orbital slot, as is standard practice for operational geostationary spacecraft. A satellite in this orbit, if left uncontrolled, would gradually drift in inclination and longitude over months and years due to gravitational perturbations from the Moon and Sun and the non-uniform mass distribution of the Earth.

Observability

Chollian-2B is not a practical target for amateur visual observation. Geostationary satellites orbit at an altitude of roughly 35,795 km — more than ninety times the altitude of the International Space Station — and even the largest among them are far too faint to be seen with the naked eye under any normal circumstances. Through a telescope, geostationary satellites appear as faint, stationary points of light that do not move against the star field, making them difficult to distinguish from background stars without careful measurement or the use of satellite-tracking software to identify their precise expected coordinates. For observers using optical aids or sensitive imaging equipment, Chollian-2B can be located using its tracked orbital elements available through this catalog and standard satellite-tracking tools, but it will appear as an extremely dim, essentially motionless point. Its geostationary position means it neither rises nor sets for ground observers within its visibility arc.