ARIRANG-5 (KOMPSAT-5)

ARIRANG-5, also designated KOMPSAT-5 in the international catalog and tracked under NORAD ID 39227, is a South Korean Earth observation satellite operated by the Korea Aerospace Research Institute (KARI). Launched on August 21, 2013, the spacecraft occupies a sun-synchronous low Earth orbit at an altitude of roughly 550 kilometers and remains operational in that orbit today. It carries the international designator 2013-042A, marking it as the primary payload of its launch event. As one of the KOMPSAT series of remote sensing satellites developed under South Korea's national space program, ARIRANG-5 represents a significant chapter in the country's pursuit of indigenous satellite technology and independent Earth observation capability.

Mission and Purpose

ARIRANG-5 belongs to the Korea Multi-Purpose Satellite program, commonly abbreviated as KOMPSAT, a long-running series of Earth observation platforms developed and managed by KARI. The KOMPSAT program was established with the dual goals of developing domestic space technology expertise within South Korea and providing the country with a reliable, sovereign source of remote sensing data for civilian and governmental applications.

What distinguishes ARIRANG-5 from earlier members of the KOMPSAT constellation is its focus on synthetic aperture radar, or SAR, imaging. While optical Earth observation satellites are limited by cloud cover and lighting conditions, SAR instruments operate by transmitting microwave pulses toward the surface and recording the reflected signals. Because microwaves penetrate clouds and do not depend on sunlight, a SAR-equipped satellite can acquire imagery of the Earth's surface in virtually any weather condition and at any time of day or night. This characteristic makes SAR satellites especially valuable for disaster monitoring, environmental surveillance, maritime domain awareness, and agricultural assessment — applications where timely data is critical and waiting for clear skies is not an option.

South Korea occupies a geographic and geopolitical position where independent monitoring capability carries particular strategic importance. The Korean Peninsula is frequently subject to cloud cover, especially during the monsoon season, and the ability to observe surface conditions regardless of weather offers meaningful advantages for both civilian resource management and national security-adjacent awareness. ARIRANG-5's SAR capability was designed to address precisely this need, complementing the optical imaging provided by other satellites in the KOMPSAT family and rounding out South Korea's remote sensing portfolio.

The specific operational status of ARIRANG-5 is not currently reflected in public catalog records with definitive confirmation, and its mission status is listed as unknown in the LowEarth tracking database. The satellite has, however, remained in orbit continuously since its 2013 launch, and its orbital parameters remain consistent with an object in controlled or at minimum stable flight.

Orbit and Tracking

ARIRANG-5 occupies a sun-synchronous orbit (SSO), a specialized class of near-polar low Earth orbit in which the satellite's orbital plane maintains a roughly constant angle relative to the Sun throughout the year. This is achieved by selecting an inclination that causes the orbit to precess at the same rate as the Earth advances in its annual journey around the Sun — approximately one degree per day. The result is that the satellite passes over any given location on Earth at approximately the same local solar time on each successive pass, a property that greatly simplifies the comparison of images taken on different dates because lighting geometry remains consistent.

ARIRANG-5's current tracked orbital elements show an apogee of 560 kilometers and a perigee of 554 kilometers, yielding an orbit that is very nearly circular. The inclination is 97.6 degrees, which is slightly retrograde relative to Earth's rotation — a typical characteristic of sun-synchronous orbits, which require an inclination slightly greater than 90 degrees to achieve the necessary nodal precession. The orbital period is 95.6 minutes, meaning the satellite completes roughly fifteen full orbits of the Earth each day.

The low eccentricity of the orbit — the difference between apogee and perigee is only six kilometers — indicates a well-maintained or inherently stable trajectory. In sun-synchronous orbits at these altitudes, atmospheric drag is present but manageable, and the slight residual eccentricity is consistent with normal long-term behavior for a spacecraft at this altitude.

ARIRANG-5 is cataloged as object 39227 in the NORAD satellite catalog and is assigned the COSPAR international designator 2013-042A. These identifiers allow the satellite to be unambiguously tracked and distinguished from other objects in the catalog, including rocket bodies and debris associated with its launch. The "A" suffix in the COSPAR designator confirms its classification as the primary payload of the forty-second launch of 2013.

Design and Operator

ARIRANG-5 was developed under the auspices of the Korea Aerospace Research Institute, the primary government research and development agency responsible for South Korea's civil space program. KARI was established in the late 1980s and has since overseen the development of the entire KOMPSAT satellite series, alongside work on launch vehicles and space science missions. The institute operates under the aegis of South Korea's science and technology ministry and has pursued a deliberate strategy of building domestic capability by combining international partnerships with incremental in-house development.

The manufacturer of ARIRANG-5 is not specified in currently available catalog records. The KOMPSAT program has historically involved international industrial partnerships in various capacities, a common approach for nations in the process of building their indigenous space technology base. Such arrangements typically allow a country to acquire technology transfer and operational experience while working toward greater self-sufficiency in future programs.

Mass and power figures for ARIRANG-5 are not recorded in the public catalog entry reviewed here. The satellite is classified as a payload object, distinguishing it from associated launch vehicle components or other ancillary objects that may have been tracked from the same launch event.

Current Status

As of the information available in the LowEarth catalog, ARIRANG-5 has not been assigned a decay or reentry date, indicating that the spacecraft remains in orbit. With an orbital altitude centered around 550 to 560 kilometers, the satellite is operating in a regime where atmospheric drag is low enough to permit extended mission lifetimes without constant propulsive maintenance, though spacecraft at these altitudes do experience slow orbital decay over timescales of years to decades depending on solar activity and any onboard propulsion.

The satellite has been in orbit for over a decade since its August 2013 launch, a span that would represent a substantial operational life for a remote sensing platform. Whether ARIRANG-5 is currently returning science or observation data is not confirmed in the catalog record, and its mission status remains listed as unknown. Regardless of its operational state, the spacecraft continues to be tracked as a resident space object and its orbital elements are updated accordingly.

Within the broader context of South Korea's space program, ARIRANG-5 occupies an important historical position. Its launch came during a period of expanding ambition for KARI and the South Korean government, bracketed by earlier optical KOMPSAT missions and later, more capable successors. The satellite helped demonstrate South Korea's ability to develop, launch, and operate a technically demanding SAR mission, contributing to the expertise base that underpins the country's continued investment in space-based Earth observation.

How to Spot It

ARIRANG-5 is a relatively small satellite in a low sun-synchronous orbit, and it is not among the class of objects routinely visible to the naked eye under typical observing conditions. That said, low Earth orbit payloads at approximately 550 kilometers altitude can occasionally be glimpsed as faint, steadily moving points of light when conditions are favorable — specifically when the observer is in twilight, the satellite is sunlit, and the sky overhead is sufficiently dark.

Because ARIRANG-5 is in a sun-synchronous orbit inclined at 97.6 degrees, it passes over a very wide range of latitudes on each orbit, making it accessible to observers across most of the populated world at some point during any given day. The 95.6-minute orbital period means the satellite completes roughly fifteen passes per day globally, though any specific ground location will only see a fraction of those passes at observable geometry.

For accurate pass predictions, observers should use the LowEarth pass prediction tool with ARIRANG-5's NORAD catalog number 39227. The tool will calculate local rise, culmination, and set times based on current orbital elements and the observer's geographic coordinates, providing the best available guidance for a spotting attempt. As with all low Earth orbit satellites, predictions more than a few days in advance carry increasing uncertainty due to the cumulative effects of atmospheric drag and other perturbations.