South Korea had been claiming they had placed their STSAT-2 scientific satellite into orbit on Tuesday, following its launch on their KSLV-1 (Korea Satellite Launch Vehicle) “Naro” rocket. However, Russian officials cited by “Interfax” are claiming the vehicle failed during second stage flight. The launch came after last week’s scrub – caused by a problem during the automated launch sequence, relating to pressurization issue.
Korea, in need of technology cooperation to develop a space launch vehicle in a short time, was able to begin space launch vehicle development through cooperation with Russia, driven by Korea’s membership in the Missile Technology Cooperation Regime (MTCR) in March 2001.
Originally, South Korea planned a completely indigenous design, but in 2005 it was announced that it would use a Russian Angara booster module as the basis of its space launcher. The program, like that of the Angara, was subject to continuous funding shortages and schedule delays.
The presidents of the two countries reached an agreement on aerospace technology cooperation, making the bilateral cooperation viable. This agreement was followed by the Korea Launch Vehicle System (KSLS) cooperation agreement between KARI and the Russian Khrunichev State Space Center in October 2004.
Although the process of signing the Technology Safeguard Agreement (TSA), the prerequisite for technology protection products, has been delayed, close cooperation in development was underway based on mutual trust between the two countries.
It was decided to develop a first stage in collaboration with Russia, based on the still-in-development Angara launcher. The first test of this vehicle was moved to 2007 and would consist of a launch of the first stage with a South Korean solid rocket motor kick stage to place the small 100-kg satellite into orbit. KARI oversaw basic system design, system management of the launcher, and basic design of the ground equipment.
South Korea has spent $402 million dollars on the project, with about 40 percent of monies going to Russia for its involvement.
The Naro (KSLV-1) launch vehicle is capable of launching a 100 kg cargo to a 300 km orbit at 38 degrees. At launch it develops a liftoff thrust of 1,910.000 kN, having a total launch mass of 140,000 kg. The launch has a diameter of 3.90 meters and a total length of 30.00 meters.
Consisting of the first stage with liquid propellant engine and the second stage with solid propellant kick motor, the 1st stage was developed in cooperation with Russia from 2004.
In April 2005, the two parties held a system design review meeting, to be followed by joint launch vehicle critical design review – however, the latter was delayed as the Technology Safeguard Agreement (TSA) – the prerequisite for major technology protection products – wasn’t signed until October 17 2006. As a result, the initial launch target, which was set for the end of 2007, could not be achieved.
The countdown, launch and satellite deployment sequence that was carried out for this mission started four days prior to launch, when the battery cells onboard Naro and the Science and Technology Satellite-2 (STSAT-2) are recharged. Three days before launch the weather conditions on launch date are checked and all systems are examined.
At T-54 hours the Naro with STSAT-2 is moved from rocket assembly complex to launch pad and fastened to the erector arm, ahead of final checks on all related mechanical systems. One day before launch engineers performed a launch rehearsal to check the vehicle’s systems and to conduct final check prior to blast off. The weather conditions around Naro Space Center are checked for strong winds and lightning weather constraints.
Four hours prior to launch all launch systems and preparations are checked, with controllers to determine the “go/no-go” conditions for the fuelling. This process is completed two hours before launch.
The chief technical controller makes the final decision to move forward or abort launch within 18 minutes of launch, and at 15 minutes before launch the automatic launch sequence begins for final countdown.
At launch, land-based tracking radar and high speed cameras following its ascent. Flying in a slightly north-easterly direction for 10 seconds after liftoff, the Naro rocket makes a “kick-turn” and veers south, 900m above launch pad at 20 seconds after launch. Max Q comes at T+55s and exceeds speed of sound 7.4 km from the ground.
The fairing is ejected 245km from launch pad at an altitude of 177km (215 seconds after launch) to permit separation of second stage rocket from main booster.
MECO comes 229 seconds after launch, followed by first and second stage separatation at T+232, 316 km downrange from Naro Space Center at an altitude of 196km. The first stage falls to earth near the Philippines.
At 395 seconds, the second stage rocket ignites at an altitude of 303 km. At this time Naro is 1,052km from its launch platform.
SECO comes at 453 seconds after launch. STSAT-2 – now at the correct trajectory for stable orbit – is at an altitude of 306km. The separation of the satellite is due at T+540s, followed by the deployment of the solar panels.
The first contact with controllers at the Korea Advanced Institute of Science and Technology in Deajeon is not scheduled until 13 hours after launch – which is where some confusion appears to have been made in some areas of the media. However, South Korea were initially claimed mission success.
Russian officials cited by the Interfax news service later claimed the second stage failed to place the satellite into orbit. More will follow.
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