South Korea’s first satellite to employ Synthetic Aperture Radar (SAR) for Earth observation and environmental monitoring is safely in orbit, following a successful launch from the Yasny base, near the village of Dombarovsky in Russia’s Orenburg Oblast. The Korean Multi-Purpose Satellite (KOMPSAT)-5 roared spectacularly aloft atop a three-stage Dnepr rocket from Site 13 at 8:39 p.m. local time (10:39 a.m. EDT) Thursday, 22 August. “The launch vehicle successfully deployed the satellite at approximately 15 minutes after launch,” said Lee Sang-ryool, an official from the Korea Aerospace Research Institute (KARI), in a post-launch statement.
Today’s mission was conducted under the auspices of Kosmotras, a commercial launch services provider owned and operated jointly by Russia, Ukraine, and Kazakhstan. The Dnepr was flying its 18th orbital mission today, having previously delivered a number of international payloads since Britain’s UoSAT-12 in April 1999. In particular, the 113-foot-tall rocket lofted Bigelow Aerospace’s Genesis-I (July 2006) and Genesis-II (June 2007) inflatable modules and has also carried satellites for Thailand, Italy, Malaysia, Saudi Arabia, Argentina, Germany, France, Belarus, Japan, South Korea, Colombia, Norway, and the United States. It has suffered one mission failure, caused by a malfunction in the pumping hydraulic drive of a combustion chamber which induced controllability problems.
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 This treaty has since been replaced by NewSTART, which received the signatures of U.S. President Barack Obama and Russian President Dmitri Medvedev in April 2010.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.
The Dnepr is an underground-silo-launched rocket, ejected by means of a hot gas generator. When it reached an altitude of about 66 feet, the first stage RD-264 engine ignited, producing 1.02 million pounds of thrust and burning for about 98 seconds. After the separation of the first stage, the second stage and its RD-0255 powerplant picked up the baton with 170,000 pounds of thrust for about 170 seconds, and finally the third stage’s single RD-869 engine injected KOMPSAT-5 into orbit. The third stage fired for a little over 600 seconds, with a thrust of 4,200 pounds.
Thirty-two minutes after liftoff, it was announced that KOMPSAT-5 had transmitted beacon signals to the Troll Satellite Station in Antarctica to confirm that it had achieved its required altitude and orbit. Further details will be provided by the Svalbard Satellite Station in Norway and by radio communication with South Korea’s ground station in Daejeon.
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 to Yasny. Following its arrival at the launch site, KOMPSAT-5 underwent checkout and testing and on 8 August the process of loading its attitude-control propellants was completed.
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. The launch of KOMPSAT-5 misses out the number 4, which is considered unlucky in Korea.