 Engineers at the Korea Aerospace Research Institute (KARI) examine the Russian-made first stage of the Korea Space Launch Vehicle 1 (KSLV-1) near the Naro Space Center in South Jeolla Province. / Korea Times |
By Kim Tong-hyung
Staff reporter
South Korea's first space rocket launch was a dismal failure, although government officials insist on calling it a ``half-success.'' The Korea Aerospace Research Institute (KARI), the country's space agency, doesn't intend to leave any doubts this time around as it prepares to light up the Korea Space Launch Vehicle 1 (KSLV-1) again for an optimistic retry on June 9.
Yet it is difficult to pinpoint the areas required for improvement, when engineers and officials are still unsure what caused KSLV-1 to fail to place its payload satellite into orbit on its maiden flight last August.
``Our engineers know that failure is not an option this time around, and we are thoroughly inspecting every single possibility,'' Cho Gwang-rae, who heads KARI's rocket development unit said.
The agency's predominant objective currently is to improve the design of the KSLV-1's second stage, the part of the rocket that holds the satellite, redoing the wiring and adjusting the mechanical structure to simplify the system and reduce the possibilities of malfunction, said the KARI official.
The Russian-made KSLV-1 was the country's inaugural launch from the brand new Naro spaceport. Russia's Khrunichev State Research and Production Space Center, which is providing the technology for the KSLV-1 project, is contracted for at least one more launch.
The Khrunichev center is responsible for developing the first-stage of the two-stage KSLV-1, which includes the rocket engine and the liquid-fuel propulsion system.
The KARI-built second-stage of the rocket is designed to hold and eject the satellite, using an ``explosive bolt'' technique whereby a set of bolts stitching the fairings with the rocket are ignited and blown apart.
KARI finished the process of inserting the payload satellite into the KSLV-1 second stage and attaching the fairings last week. The next step is to connect the top half of the rocket to the Russian-built first-stage, a process that will begin next Monday and be completed sometime near the end of the month.
KARI conducted a flight simulation test to examine the flight tracking systems at the Naro Space Center and a second tracking station in Jeju Island, using a light airplane carrying mock-ups of the machinery that will be used in the actual rocket launch.
``The adjustments have been made and the results of the tests have been positive,'' said Ryu Guk-hui, an official from the space development division at the Ministry of Education, Science and Technology.
Blowing it the right way
The KSLV-1 achieved the desired speed and altitude during its Aug. 25 launch from the Naro Space Center in South Jeolla Province, but failed to properly unload the Science and Technology Satellite No. 1 (STSAT-1). The spacecraft is believed to have burned up in the atmosphere before it crashed back to Earth.
Shortly after the first launch, KARI officials said that the KSLV-1's failure to deliver the satellite into orbit was because one of the fairings, the part of the rocket that protects the satellite during the ascent, didn't separate properly.
However, an independent panel, led by Korea Advanced Institute of Science and Technology (KAIST) aerospace expert Lee In, was unable to produce a conclusive argument in reporting the results of their investigation in February, although narrowing the possibilities to either electrical problems or a mechanical flaw.
``The investigation panel went through every possibility and suggested ways to eliminate the sources of the potential problems. We had redesigned and tested a new triggering system in January, and conducted the separation tests for the fairings in ground tests,'' said a KARI official.
In KSLV-1's maiden flight, one of the fairings somehow remained attached 216 seconds after liftoff, when the explosives were timed to go off.
The last fairing remained attached to the launcher 540 seconds after liftoff, and was likely knocked off by the satellite as it ejected. It is believed that an electrical discharge or mechanical flaw prevented a section of the explosive bolts from going off properly.
For the second launch, KARI officials made adjustments to reduce the possibility of a discharge, using cables with better discharge resistance and molding the wires that connect the trigger and fairing separation system.
The new design also guards against the possibility of flaws in the fairing separation systems. Should a malfunction occur on one side of the fairings, the opposite side will be programmed to ignite the muted explosive bolts, KARI officials said.
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