Arirang / KOMPSAT - Optical

Korea developed the low orbit earth observation multipurpose satellites Arirang 1 and 2 and launched them in 1999 and 2006, respectively. The Korea Multi-Purpose Satellite Arirang 1 was jointly developed with a US-based enterprise as Korea had no experience of developing a multipurpose satellite at that time. However, the development of Arirang 2 was led by Korean scientists and engineers based on the experience of developing Arirang 1. The development of the Korea Multi-Purpose Satellite Arirang 2 enabled Korea to achieve a rate of self-sufficiency of 91.5% in satellite design and 65.2% in the fabrication of satellite parts. Korea also became the seventh country in the world to possess a 1m-class high-resolution satellite. It is significant that it was achieved in only around ten years after the country began the development of a satellite.

The foundations for independent satellite technology attained through the development of Arirang 1 and 2 led to the development of Arirang 3, which is capable of 70cm resolution optical observation, Arirang 5, which is equipped with imaging radar, and Arirang 3A, which is capable of 55cm resolution optical and IR observation.

The South Korean reconnaissance satellite Kompsat 3 / Arirang-3 (Korean Multi-purpose Satellite 3) was launched from Japan’s Tanegashima Space Center on 17 May 2012. KOMPSAT-3 is the first sub-meter optical satellite developed and operated by the Korea Aerospace Research Institute (KARI). Orbiting at 685 kilometers (km), KOMPSAT-3 collects 70-centimeter (cm) panchromatic and 2.8-meter (m) 4-band multispectral (i.e. blue, green, red and near-infrared/NIR) imagery. KOMPSAT-3 differs from other multispectral high-resolution satellites with afternoon collection times and 14-bit depth imagery. This makes the Korean satellite an excellent choice for agricultural studies as well as a compliment to imagery collected in the morning.

The South Korean military began pushing in 2013 to deploy spy satellites to strengthen its surveillance of North Korea in light of growing missile and nuclear threats from the communist country. South Korea currently operated Arirang-3, a multipurpose satellite, which provided geographical information on the Korean Peninsula including North Korea's missile and nuclear test sites. However, it still relied on the United States for much of its intelligence due to the commercial satellite's limited capabilities.

Although the South Korean military can mobilize various intelligence assets to monitor the North Korean military's activities, its capability is limited in observing the control command and supporting facilities in the North. To be able to independently monitor the enemy's activities, the military planned to include deployment of military spy satellites in the mid- and long-term plan.

With adding reconnaissance satellites to its monitoring capabilities, the military hopes to increase its surveillance of major North Korean military facilities to better anticipate aggressive actions from the communist state. Demands for advanced spy satellites increased after the North successfully launched a long-range rocket in December 2012.

During a meeting of the defense project committee, on 11 June 2014 the government decided to begin developing a military reconnaissance satellite, which is capable of securing imagery intelligence on the Korean Peninsula and the surrounding regions, in 2015. Five satellites will be deployed in the early 2020s, the Defense Acquisition Program Administration (DAPA) said, with an official noting that some 1 trillion won (US$983 billion) is to be earmarked for their development and production.

Aside from developing spy satellites, the Air Force is considering an early warning satellite system, which can detect missiles, spacecraft launches and nuclear explosions using sensors that can detect the infrared emissions from these intense sources of heat.

On April 8, 2013 KARI (Korea Aerospace Research Institute) announced the start of commercial services of KOMPSAT-3 after in-orbit validation on 29 March, 2013. Now, Satrec Initiative will distribute KOMPSAT-3 imagey on a world-wide basis. KOMPSAT-3 provides 0.7m panchromatic and 2.8m multispectral imagery. KOMPSAT-3 has a unique local access time of 13:30 hours, and the imaging capability in the afternoon will increase the chance of acquiring cloud-free images over specific targets for the end users.

The Korea Multi-Purpose Satellite Arirang 3A is an earth observation satellite equipped with a 55cm class high-resolution EOC and Korea's first IR sensor. The high-resolution electronic optical camera AEISS-A (Advanced Earth Imaging System-A) developed with Korean technology and mounted on Arirang 3A features 55cm class optical photography, which is the highest resolution among cameras mounted on domestic satellites. The IR sensor, which is capable of detecting heat on the ground, is used to observe fire, volcanic activity and urban thermal islands during day and also nighttime. Arirang 3A operates in the sun’s synchronous orbit at an altitude of 528km and passes over Korea twice (day and night), photographing the Korean Peninsula for up to 50 minutes each day. The main body of Arirang 3A was developed by a private enterprise, while KARI transferred the technology to expand the domestic satellite industrial base.

An electronic optical camera is installed in the earth observation satellite, which takes pictures of the ground objects in the visible spectrum range that can be seen with the naked eye. Based on the technology acquired from the development of Korea Multi-Purpose Satellites Arirang 1 and 2, KARI independently developed the world-class electro-optical payloads AEISS (Advanced Earth Imaging Sensor System) and AEISS-A (Advanced Earth Imaging Sensor System-A). AEISS and AEISS-A were installed in Arirang 3 and 3A, respectively.

The AEISS accommodated on Arirang 3 is a 70cm resolution optical camera, which means that it can make the image of each people on the ground into a dot which can be distinguished from adjacent ones and accurately identify small cars moving on the ground while the satellite flies at 7km/s at an altitude of around 700km, which is roughly the distance between Pyeongyang and Jeju Island. For a commercial purpose observation satellite, this performance is among the world's top 5.

With the exception of the part manufacturing, AEISS was developed by KARI from its design to the assembly, alignment, and testing, as well as the final verification test in the space environment. Since a high performance camera like AEISS can be hardly developed through technology transfer or joint development, it is a technology that must be thoroughly acquired in house for the successive development and improvement of the high-performance earth observation satellites.

The development process is also very complicated. First of all, ultra-precision technology to the level of 1/5000 of a human hair is needed for the assembly of an optical system mainly consists of the reflectors and the structures. Moreover, even micro-vibrations generated by a human or vehicle near the building can cause a measurement error. This ultrasensitive instrument must be operated for 3~7 years under vacuum conditions and temperature difference of more than 100°C after withstanding a launch environment which gives shocks tens of times of gravity. That is why only a few counties such as the US, and France have been able to develop the state-of-the-art satellites with the electro-optical cameras like AEISS.

AEISS-A is a sister model of AEISS developed by KARI. Its optical resolution is 55cm, and it includes an IR channel to enable nighttime photography and heat sensing. To achieve this, the electronic module of AEISS was upgraded, and the IR channel developed in Korea was added to it. The higher resolution was obtained by solving the problems related to the shorter integration time and undesirable noise signals caused by lowering the altitude from 685km to 528km.

The Ministry of Science, ICT and Future Planning announced on 06 September 2016 that a multipurpose satellite that will observe natural disasters and the environment of the Korean Peninsula will be developed with domestic technology. The ministry said that the Korea Aerospace Research Institute will lead the project for developing the satellite named Arirang 7. A total of 310 billion won will be injected into the project with the aim of launching the satellite in 2021. The entire procedures of designing and putting together the satellite will be carried out using domestic technology.

The Arirang 7 will be equipped with an optical camera with a zero-point-three meter resolution, enabling it to distinguish whether a vehicle is a small car or a truck. Having an attitude control system, the satellite will be able to change its position eight to nine times when taking images of a certain place. The Arirang 3A, which was launched in March of last year, can determine the existence of cars on the Earth’s surface and change positions three times when taking imagery of one place.

South Korea's military plans to deploy five reconnaissance satellites, developed on its indigenous technology, by 2022 as part of its "Kill Chain" strategy to preemptively detect and destroy nuclear and missile threats from the Democratic People's Republic of Korea (DPRK), Yonhap news agency reported on 08 August 2016. South Korea's Defense Acquisition Program Administration (DAPA) said that the arms procurement agency will hold an explanation session on for the project to develop its homegrown reconnaissance satellite. During the session, the agency plans to explain how to proceed on the project, while listening to potential developer companies. It reportedly has a plan to give the public notice of a bid in September 2016 and sign a deal with bidders by the end of 2016.

The military will spend about 1 trillion won (900 million U.S. dollars) on the project. The Agency for Defense Development under Seoul's defense ministry will develop synthetic aperture radar (SAR), while the Korea Aerospace Research Institute (KARI) will be responsible for development of electro-optica and infrared ray instruments. One homegrown satellite will be deployed first in 2020, with two set to be installed in 2021. The remaining two will be put into orbit in 2022. When deployed, those satellites will be capable of detecting the DPRK's mobile missile launchers within two to three hours on average. The indigenous satellite development is part of its Kill Chain system to preemptively detect and destroy the DPRK's possible missile attacks. The Kill Chain is South Korea's own missile defense program along with the Korea Air and Missile Defense (KAMD) system.

A Defense Ministry official in Seoul said 18 October 2016 the South's military is exploring the idea of leasing surveillance satellite capability from Israel in particular. Because Israel uses its spy satellites mainly to monitor the Middle East, it may be feasible for South Korea to secure operating rights during periods when the satellites pass over the Korean peninsula. Seoul is aiming to boost its indigenous satellite overwatch technology, but is unlikely to have anything on a par with today's U.S. and Israeli satellites until about 2023. South Korea presently relies heavily on U.S. military reconnaissance satellites to gather intelligence on North Korean military activities, such as the recent launch of a Musudan missile, but wants to be able to monitor the North more directly on its own.