South Korea’s first dedicated satellite to utilize Synthetic Aperture Radar (SAR) for Earth observations and environmental monitoring is scheduled to fly from the Yasny launch site, near the village of Dombarovsky in Russia’s Orenburg Oblast, on Thursday, 22 August. The Korea Multi-Purpose Satellite (KOMPSAT)-5 will be carried aboard a three-stage Dnepr rocket from Yasny’s Site 13, and the campaign is being conducted by Kosmotras, a commercial launch services provider operated jointly by Russia, Ukraine, and Kazakhstan.
Standing 113 feet tall and weighing an estimated 470,000 pounds, the Dnepr is a converted, Soviet-era SS-18 intercontinental ballistic missile, decommissioned from military service with Russia’s Strategic Rocket Forces as part of the provisions of the 1991-signed Strategic Arms Reduction Treaty (START). This treaty has since been replaced by NewSTART, which received the signatures of U.S. President Barack Obama and Russian President Dmitri Medvedev in April 2010.
As a potential weapon of war, the SS-18 achieved a 97 percent success rate and since April 1999 has flown 17 orbital missions, five from Yasny and 12 from Baikonur in Kazakhstan. All three of its stages utilize unsymmetrical dimethyl hydrazine, with an oxidizer of nitrogen tetroxide, and the vehicle has the capability of inserting 8,000 pounds of payload into a low-Earth orbit of up to 180 miles altitude or 5,000 pounds into a Sun-synchronous, geocentric orbit of up to 180 miles altitude.
On its first mission, launched from Baikonur on 21 April 1999, the Dnepr lofted Britain’s UoSAT-12 mini-satellite into low-Earth orbit. Since then, it has carried a range of payloads into orbit, most notably Bigelow Aerospace’s Genesis-I (July 2006) and Genesis-II (June 2007) inflatable modules. Satellites from Thailand, Italy, Malaysia, Saudi Arabia, Argentina, Germany, France, Belarus, Japan, South Korea, Colombia, Norway, and the United States have also been boosted into orbit by the Dnepr.
Only one of its 17 missions has ended in failure. Back in July 2006, a malfunction in the pumping hydraulic drive of a combustion chamber induced roll, pitch, and yaw instability and the vehicle crashed about 90 miles from the Baikonur pad. Although it hit the ground in an unpopulated region of Kazakhstan, the debris released toxic pollutants and the Russian government was forced to pay $1.1 million in compensation.
The Dnepr for Thursday’s launch arrived at Yasny for final processing in June 2013, followed by the KOMPSAT-5 payload on 11 July. The satellite was airlifted from Incheon Airport in the Republic of Korea to Orsk, Russia, aboard an Antonov-124 Ruslan aircraft, after which it was transported overland by truck to Yasny. Since its arrival at the launch site, KOMPSAT-5 has undergone checkout and testing, and on 8 August the process of loading its hydrazine attitude-control propellants and pressurant gas was completed.
The first stage of the Dnepr is powered by a single RD-264 engine, which will produce 1.02 million pounds of thrust at liftoff and burn for 130 seconds. After it has been exhausted and separated, the RD-0255 powerplant of the second stage will pick up the baton with 170,000 pounds of thrust for 190 seconds, leaving the third stage and its single RD-869 engine for the longest burn to inject KOMPSAT-5 into orbit. The third stage will ignite for 1,000 seconds—more than 16 minutes—with a thrust of 4,200 pounds. Upon the completion of this firing, KOMPSAT-5 will be separated from the vehicle.
This mission is South Korea’s first to employ X-band SAR technology and is expected to spend up to five years performing all-weather, 24-hour observations of the entire Korean Peninsula. From an orbit of 310-370 miles, inclined at 97.6 degrees, the radar data from KOMPSAT-5 should enable ground resolutions as fine as 1 meter (3.3 feet). It will fulfil Geographic Information Systems (GIS) requirements, together with ocean monitoring, land management, disaster monitoring, and environmental monitoring roles. As a secondary task, it will also perform atmospheric sounding and radio occultation science experiments with a dual-frequency GPS receiver and laser retroreflector array.
Developed by the Korea Aerospace Research Institute (KARI), the KOMPSAT-5 mission is the latest in a long line of Earth-resources spacecraft despatched by South Korea. Its predecessors included KOMPSAT-1, launched in December 1999 atop a Taurus rocket from Vandenberg Air Force Base, Calif., and KOMPSAT-2, which flew aboard a Rockot vehicle in July 2006. These two opening missions evaluated electro-optical cameras, ocean-scanning multi-spectral imagers, high-energy particle detectors, and ionospheric measurement sensors and demonstrated their worth in surveillance of natural disasters, utilization of mineral resources, cartography, and GIS construction.
Most recently, a Japanese H-IIA launch vehicle boosted KOMPSAT-3 into orbit in May 2012. This satellite employs a high-resolution, electro-optical camera and is presently a year into a planned four-year mission to provide continuous high-resolution imagery of Earth for GIS, environmental, agricultural, and oceanographic monitoring applications.