2009-08-25 18:04
Satellite Fails to Enter Orbit
By Kim Tong-hyung Staff Reporter GOHEUNG, South Jeolla Province _ South Korea bumbled its way into the Asian space race Tuesday, with the Naro Space Center witnessing the liftoff of the country’s first space rocket, Korea Space Launch Vehicle 1 (KSLV-1). However, the satellite that the launcher was delivering may just be lost in space or dumped at sea. The two-stage rocket, developed with the help of Russia, was intended to put a 100-kilogram satellite, the Science Technology Satellite No.2 (STSAT-2) into the lower Earth orbit. The Korea Aerospace Research Institute (KARI), the country's space agency, said that the satellite was separated from the second stage of the rocket nine minutes after the 5 p.m. launch as planned. But the spacecraft was then 342 kilometers above waters near Australia, instead of the 306-kilometer attitude it was supposed to hit. The satellite was programmed to send back signals to a Korea Advanced Institute of Science and Technology (KAIST) research center in Daejeon early Wednesday. However, the STSAT-2 is not likely to contact the ground facilities in time, if it ever does, as KARI officials have yet to confirm whether the satellite remains in a position to circle the Earth or bounced off completely into the abyss. A successful contact would have made Korea the 10th country in the world to deliver a locally-developed spacecraft into orbit from its own spaceport. "The first stage of the Naro rocket (KSLV-1), and the 'kick motor' of the second stage functioned, and the satellite was separated from the second stage. However, the current data shows that the satellite was not delivered in the precise position we had intended, and we have formed a technical committee with the Russian engineers to analyze what went wrong," said Ahn Byung-man, the minister of Education, Science and Technology, in a news conference here. "It would have been great if everything went well, but we believe analyzing what prevented the satellite from reaching the targeted position will be an invaluable experience for us in advancing our space technologies." KARI President Lee Ju-jin said it was unclear whether the satellite had entered some kind of orbit or is destined to be expensive tech junk. "We are trying to find by how much the STSAT-2 missed the targeted orbit," Lee said. "The satellite doesn't have a propulsion system," he added, meaning that the spacecraft isn't able to adjust its position on its own. The two-stage KSLV-1 is the heaviest and most powerful rocket ever to be lit up in Korean territory, standing 33 meters tall, weighing 140 tons and capable of generating a thrust of 170 tons at launch. The KSLV-1 first stage, containing the rocket engine and a liquid-fuel propulsion system, was developed by Russia's Khrunichev State Space Science and Production Center, which is providing technology for the project. The second stage of the rocket, which burns solid fuel and designed to hold satellites, was developed by KARI. Although KARI officials expressed regret over the misplaced satellite, it's difficult to say that was the priority. Using a massive, 140-ton launcher that generates more than 170 tons in thrust to carry a satellite as little as STSAT-2, when the payload capacity is likely several times bigger than that, is a proof that Naro engineers were focused on poking into the higher skies and not much more. But it's hard to deny that Tuesday's failure equals as a harsh reality check for Korean space technology. It seems that the KSLV-1 first stage, developed by the experienced Russians, worked perfectly. However, the rocket's Korean-made second stage, which was supposed to carry and push the satellite into its place, apparently had some issues. Kwon Se-jin, a professor of aerospace engineering at KAIST, said that there is a possibility that the "kick motor" in the KSLV-1 second stage, which is used to position the satellite into orbit, was never ignited. This would mean that the STSAT-II fell and is now lost at sea. "Korea has a wealth of experience in solid-fuel rocket engines, but most of the technology was developed for missiles. It is known that solid-fuel engines are harder to ignite when they are in space," Kwon said. "After the second stage is separated from the first stage at 340 kilometers or more, it would normally move at 7 to 8 kilometers per second when unassisted. That is not enough speed to overcome the Earth's gravity, and the role of the kick motor is to push this speed up to 10 kilometers per second, and thus, deliver the rocket into orbit." The team of Korean and Russian engineers at the Naro spaceport first attempted to launch the KSLV-1 last Wednesday, but a software flaw forced the launch to be called off less than eight minutes before the scheduled blast-off. This forced the Ministry of Education, Science and Technology to move the launch to Tuesday, before the closing of the current "launch window" reported to international aviation and maritime authorities that extends until Wednesday. The Khrunichev Center will prepare a second launch sometime between April and May next year, and is also contracted for a third launch should the second try end up a failure, KARI officials said. The engineers at Naro, named after an island where a launch site is located, Monday completed a technical rehearsal to evaluate the rocket's machinery and launch support equipment, in which they found no anomalies. The country spent about $402 million on the KSLV-1 project, which suffered its share of setbacks before Tuesday's lift-off. The KSLV-1 project is crucial for the Koreans, who have been attempting to join neighboring nations such as China, Japan and India in the Asian space race. Korea has already launched 10 indigenously produced satellites using the rockets and launch services of other countries. It also aims to build an unmanned space probe by 2025 that can reach the moon. The KSLV-1 launch was crucial for the Russians as well, as it equaled as the first stage test for their yet-to-be-flown "Angara" rocket, which has been in development since the mid-1990s and is expected to make its maiden flight in 2011. The KSLV-1 is designed with the same structural elements in an Angara first stage, including its rocket engine. Its RD-151 rocket engine, developed by Russia's NPO Energomash, is basically a derivative of the RD-191M engine that will be used for the Angara 1.1, the first rocket in the Angara family. Gains and Losses The launch was originally scheduled for late 2005, but was postponed six times before the science ministry settled on Aug. 19 earlier this month. The Khrunichev Center's failure to deliver on ground-test vehicle (GTV), a mock-up model of the rocket to be used for testing, was a cause of frustration last year. And the completion of the Naro spaceport took longer than expected, with the devastating earthquake in southwest China in May last year resulting in the late delivery of some key parts. And in late July, the Russian team hesitated again, claiming that they needed more time to ensure that the KSLV-1's rocket engine and propulsion system was functioning properly. This was despite that the flight model (FM) of the KSLV-1, or the rocket that was used for the actual launch, was delivered to Korea a month earlier. The KLSV-1 was finally strapped to the launching pad last Monday, but an automatic abort system was triggered with less than eight minutes left in the countdown when weak pressure was detected in a helium pressure tank used to control valves in the rocket engine. KARI officials later confirmed that there was nothing wrong with the tank, but software malfunction had caused the computerized system to read the data incorrectly. KARI engineers and government officials have also been uneasy about the controversy over their nature of collaboration with their Russian partners. The technology safeguard agreement (TSA) signed between Russia and Korea bans any technology transfer regarding the KSLV-1 first stage. And there has been debate on why Korea is using its taxpayers' money to finance what is basically a Russian rocket experiment when it is getting an unproven product in return. However, Tahk Min-jae, a KAIST rocket scientist who worked as an advisor for the KSLV-1 project, said that the significance of the launch should not be discounted. "We are not blowing money in the wind, as Korean space technology is taking a big step forward," Tahk said. "The experience of building the spaceport, and operating all the launch support equipment, computer systems and launch sequence are an invaluable experience that could be just as critical as advancing our technologies for developing liquid-fuel rocket engines. "The software used to regulate the launch process was developed by the Khrunichev Center, but actually, I think we already have the technology to produce better software. However, what we do from now is even more important, and the most immediate goal would be building a rocket test center at the Naro spaceport, where we can fire up rocket engines and analyze data." thkim@koreatimes.co.kr |
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